Clarify site build and deploy scripts

Fix JSR license metadata
Bump Rust crates for breaking release
2026-08-13 19:53:38 +09:00 · 2026-08-13 19:45:04 +09:00 · 2026-08-13 19:40:08 +09:00 · 2026-08-13 19:31:21 +09:00 · 2026-08-13 19:01:14 +09:00 · 2026-08-13 18:55:03 +09:00
147 changed files with 31523 additions and 3397 deletions
@@ -3,3 +3,9 @@
 /.env
 /.yoi
 /result
+node_modules
+/dist
+site/decodal-site/dist
+
+# Astro
+site/decodal-site/.astro
@@ -12,25 +12,221 @@ dependencies = [
 ]

 [[package]]
-name = "decodal"
-version = "0.1.0"
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bumpalo"
+version = "3.20.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72f5acc6cb2ba439de613abc23857ec3d78374d8ed5ac84e9d11336e87da8649"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d85363c37faeca707aef026efa9f3b34d077bce547e48f770770625c6013679e"
 dependencies = [
- "decodal-core",
+ "crossbeam-utils",
 ]

 [[package]]
-name = "decodal-core"
-version = "0.1.0"
+name = "crossbeam-utils"
+version = "0.8.22"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61803da095bee82a81bb1a452ecc25d3b2f1416d1897eb86430c6159ef717c17"
+
+[[package]]
+name = "decodal"
+version = "0.2.0"
 dependencies = [
+ "decodal-derive",
 "regex",
 ]

+[[package]]
+name = "decodal-cli"
+version = "0.2.0"
+dependencies = [
+ "decodal",
+]
+
+[[package]]
+name = "decodal-derive"
+version = "0.1.3"
+dependencies = [
+ "decodal",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.117",
+]
+
+[[package]]
+name = "decodal-language-service"
+version = "0.2.0"
+dependencies = [
+ "decodal",
+]
+
+[[package]]
+name = "decodal-language-tools"
+version = "0.2.0"
+dependencies = [
+ "decodal",
+ "serde_json",
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "decodal-lsp"
+version = "0.2.0"
+dependencies = [
+ "decodal",
+ "decodal-language-service",
+ "decodal-language-tools",
+ "lsp-server",
+ "lsp-types",
+ "serde_json",
+]
+
+[[package]]
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+version = "0.2.0"
+dependencies = [
+ "decodal",
+ "decodal-language-service",
+ "js-sys",
+ "serde-wasm-bindgen",
+ "serde_json",
+ "wasm-bindgen",
+]
+
+[[package]]
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+checksum = "17c704e9dbe1ddd863da1e6ff3567795087b1eb201ce80d8fa81162e1516500d"
+dependencies = [
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+
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "92d699e522242e69e3003b94ecc1f960f3a5e015aa7c5d7486e65ad01dd94f5e"
+
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+checksum = "cd417de3d1d015fc3bfd2b1ea46dfc7bab72ef86f1cc7cc9c78e728b34a6d1fd"
+
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0d50a92467f8ba5dd6e3ee5d4bd04d73ab2e4e1c44474a0674821dfce14b79bc"
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+dependencies = [
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+ "futures-util",
+ "wasm-bindgen",
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+[[package]]
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ceec5bc11778974d1bcb055b18002eba7f4b3518b6a0081b3af5f21666da9ad"
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+[[package]]
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+version = "0.10.0"
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+checksum = "3ee25a31f2e571e426eef2896179450cafc7e2f5be00d8a93b1c2d21c0ff7656"
+dependencies = [
+ "crossbeam-channel",
+ "log",
+ "serde",
+ "serde_derive",
+ "serde_json",
+]
+
+[[package]]
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+checksum = "53353550a17c04ac46c585feb189c2db82154fc84b79c7a66c96c2c644f66071"
+dependencies = [
+ "bitflags",
+ "fluent-uri",
+ "serde",
+ "serde_json",
+ "serde_repr",
+]
+
 [[package]]
 name = "memchr"
 version = "2.8.2"
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 checksum = "88904434abc2901f197fe8cc55f0445e7ded921dba5911dad2e2b39b48e663c4"

+[[package]]
+name = "once_cell"
+version = "1.21.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f7c3e4beb33f85d45ae3e3a1792185706c8e16d043238c593331cc7cd313b50"
+
+[[package]]
+name = "pin-project-lite"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
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+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "regex"
 version = "1.12.4"
@@ -59,3 +255,159 @@ name = "regex-syntax"
 version = "0.8.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d6f6ff9a378485b298a5286656da665ba74413d36db0979633275d2e708145d4"
+
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+checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
+
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+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
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+ "serde_derive",
+]
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+ "js-sys",
+ "serde",
+ "wasm-bindgen",
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+dependencies = [
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+ "serde",
+ "serde_core",
+ "zmij",
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+
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@@ -2,12 +2,23 @@
 members = [
  "crates/decodal-core",
  "crates/decodal-cli",
+  "crates/decodal-wasm",
+  "crates/decodal-derive",
+  "crates/decodal-language-tools",
+  "crates/decodal-language-service",
+  "crates/decodal-lsp",
 ]
-resolver = "3"
+exclude = ["editors/tree-sitter-decodal"]
+resolver = "2"

-[profile.release]
-opt-level = "z"
-lto = true
-codegen-units = 1
-strip = true
-panic = "abort"
+[workspace.package]
+version = "0.2.0"
+edition = "2024"
+rust-version = "1.85"
+license = "MIT OR Apache-2.0"
+repository = "https://gitea.hareworks.net/Hare/Decodal"
+readme = "README.md"
+
+[workspace.dependencies]
+serde_json = "1"
+wasm-bindgen = "0.2"
@@ -0,0 +1,173 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
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+6. Trademarks. This License does not grant permission to use the trade
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+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
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+   liable to You for damages, including any direct, indirect, special,
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+   Work (including but not limited to damages for loss of goodwill,
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+9. Accepting Warranty or Additional Liability. While redistributing
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+
+END OF TERMS AND CONDITIONS
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Decodal contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
@@ -0,0 +1,105 @@
+# Decodal
+
+Decodal is a small deterministic DSL for describing, composing, validating, and materializing structured data.
+
+It is designed around a lightweight Rust library:
+
+- host-supplied source and structured-value imports through `ImportLoader`
+- shared host environments for production and semantic editor tooling
+- no filesystem access in the library core
+- concrete and abstract values with constraints and defaults
+- deterministic expression evaluation
+- optional regex support behind a Cargo feature
+- browser playground support through WebAssembly
+
+## Library crate
+
+Embedded hosts should depend on `decodal` and provide imports with an `ImportLoader`.
+
+```toml
+[dependencies]
+decodal = "0.1"
+```
+
+## Derive support
+
+For embedded Rust applications, Decodal can generate a schema and typed decoder from a Rust struct with the `derive` feature.
+
+```toml
+[dependencies]
+decodal = { version = "0.1", features = ["derive"] }
+```
+
+```rust
+use decodal::{Decodal, DecodalDecode, DecodalSchema, Engine};
+
+#[derive(Decodal)]
+struct Service {
+    name: String,
+    #[decodal(gt = 443, default = 8443)]
+    port: i64,
+    #[decodal(rename = "feature.enable", default = true)]
+    feature_enabled: bool,
+}
+```
+
+The derive implements:
+
+- `DecodalSchema`, which produces a host schema for `Engine::bind_global`
+- `DecodalDecode`, which converts materialized `Data` into the Rust struct
+
+## CLI
+
+A standalone CLI is kept in this repository as the `decodal-cli` workspace package.
+It builds a `decodal` binary, but it is not the primary crates.io package.
+
+Run a Decodal file from the repository:
+
+```sh
+cargo run -q -p decodal-cli -- examples/advanced/main.dcdl
+```
+
+Enable optional regex support when needed:
+
+```sh
+cargo run -q -p decodal-cli --features regex -- examples/regex/main.dcdl
+```
+
+## Language server
+
+The `decodal-language-service` crate provides transport-independent evaluation and completion, while `decodal-lsp` exposes it through the Language Server Protocol with live semantic diagnostics and document formatting.
+Its library API accepts the same host environment used for production evaluation, so application-defined globals and structured import routing remain available in the editor.
+
+```toml
+[dependencies]
+decodal = "0.2.0"
+decodal-language-service = "0.2.0"
+decodal-lsp = "0.2.0"
+```
+
+Run the default filesystem-backed server from the repository:
+
+```sh
+cargo run -q -p decodal-lsp
+```
+
+Embedded applications can implement `decodal_lsp::LspEnvironment` for their existing `HostEnvironment` and construct it from the `InitializeParams` passed to `decodal_lsp::run_stdio`.
+
+## Web playground
+
+The static documentation site and browser playground live under:
+
+```text
+site/decodal-site/
+```
+
+Browser hosts can use `decodal-wasm`. Its `DecodalLanguageService` accepts JavaScript-owned `globals`, `loadImport`, and `completeImport` callbacks; filesystem and virtual-project policy remain outside the package.
+
+## License
+
+Licensed under either of:
+
+- Apache License, Version 2.0
+- MIT license
+
+at your option.
@@ -0,0 +1,61 @@
+# Releasing Decodal
+
+Run all commands from the repository root. Publishing requires Cargo, npm, and JSR credentials; validation does not.
+
+## Versions
+
+- `decodal-derive`: `0.1.3` (already published)
+- Other published Rust crates: `0.2.0`
+- `decodal-wasm` npm/JSR package: `0.1.4`
+- `decodal-codemirror`: `0.1.6`
+
+The npm packages advertise the repository's dual `MIT OR Apache-2.0` license.
+JSR metadata uses the single `MIT` identifier required by its publisher; both license files remain included in every package.
+
+## Validate
+
+```sh
+cargo fmt --check
+cargo test --workspace
+cargo test -p decodal --no-default-features
+cargo clippy --workspace --all-targets -- -D warnings
+cargo clippy -p decodal-wasm --target wasm32-unknown-unknown -- -D warnings
+cargo clippy -p decodal-language-tools --target wasm32-unknown-unknown -- -D warnings
+npm --prefix site/decodal-site run build:wasm
+npm --prefix packages/decodal-codemirror test
+npm --prefix site/decodal-site test
+npm --prefix site/decodal-site run build
+deno check packages/decodal-wasm/mod.ts
+npm pack --dry-run ./packages/decodal-wasm
+deno publish --dry-run --config packages/decodal-wasm/jsr.json
+npm pack --dry-run ./packages/decodal-codemirror
+deno publish --dry-run --config packages/decodal-codemirror/jsr.json
+```
+
+## Publish Rust crates
+
+Publish in dependency order. Wait for each crate to become available in the crates.io index before continuing.
+Run the corresponding command with `--dry-run` immediately before each real publish.
+
+```sh
+cargo publish -p decodal
+cargo publish -p decodal-language-service
+cargo publish -p decodal-language-tools
+cargo publish -p decodal-lsp
+```
+
+`decodal-cli` and the Rust `decodal-wasm` wrapper remain repository-only packages.
+
+## Publish JavaScript packages
+
+The WASM build regenerates and normalizes both committed npm/JSR packages before publishing.
+
+```sh
+npm --prefix site/decodal-site run build:wasm
+npm publish ./packages/decodal-wasm
+deno publish --config packages/decodal-wasm/jsr.json
+npm publish ./packages/decodal-codemirror
+deno publish --config packages/decodal-codemirror/jsr.json
+```
+
+After both registries accept the release, tag the release commit and update the deployed site.
@@ -1,11 +1,23 @@
 [package]
+name = "decodal-cli"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Command-line interface for the Decodal data description language."
+keywords = ["decodal", "dsl", "config", "cli"]
+categories = ["command-line-utilities", "config"]
+publish = false
+
+[[bin]]
 name = "decodal"
-version = "0.1.0"
-edition = "2024"
+path = "src/main.rs"

 [features]
 default = []
-regex = ["decodal-core/regex"]
+regex = ["decodal/regex"]

 [dependencies]
-decodal-core = { path = "../decodal-core" }
+decodal = { version = "0.2.0", path = "../decodal-core" }
@@ -4,19 +4,22 @@ use std::{
    process::ExitCode,
 };

-use decodal_core::{Data, Diagnostic, DiagnosticKind, Engine, LoadedSource, SourceLoader, Span};
+use decodal::{
+    Data, Diagnostic, DiagnosticKind, Engine, ImportLoader, LoadedImport, LoadedSource, SourceId,
+    Span, format_diagnostic_with,
+};

 fn main() -> ExitCode {
    match run() {
        Ok(()) => ExitCode::SUCCESS,
        Err(error) => {
-            print_diagnostic(&error);
+            eprintln!("{error}");
            ExitCode::FAILURE
        }
    }
 }

-fn run() -> Result<(), Diagnostic> {
+fn run() -> Result<(), String> {
    let mut args = env::args().skip(1);
    let first = args.next().unwrap_or_else(|| String::from("--help"));
    match first.as_str() {
@@ -25,7 +28,7 @@ fn run() -> Result<(), Diagnostic> {
            Ok(())
        }
        "--version" | "-V" => {
-            println!("Decodal {}", decodal_core::version());
+            println!("Decodal {}", decodal::version());
            Ok(())
        }
        "check" => {
@@ -51,12 +54,19 @@ fn run() -> Result<(), Diagnostic> {
    }
 }

-fn materialize_path(path: &str) -> Result<Data, Diagnostic> {
-    let root = read_root_source(path)?;
+fn materialize_path(path: &str) -> Result<Data, String> {
+    let root = read_root_source(path).map_err(format_raw_diagnostic)?;
+    let root_name = root.name.clone();
    let mut engine = Engine::new(FsLoader);
-    let module = engine.add_root_source(root.key, root.name, &root.source)?;
-    let value = engine.eval_module(module)?;
-    engine.materialize(&value)
+    let module = engine
+        .add_root_source(root.key, root.name, &root.source)
+        .map_err(|error| format_diagnostic_with_root(&error, &root_name))?;
+    let value = engine
+        .eval_module(module)
+        .map_err(|error| engine.format_diagnostic(&error))?;
+    engine
+        .materialize(&value)
+        .map_err(|error| engine.format_diagnostic(&error))
 }

 fn read_root_source(path: &str) -> Result<LoadedSource, Diagnostic> {
@@ -85,12 +95,12 @@ fn read_root_source(path: &str) -> Result<LoadedSource, Diagnostic> {
 #[derive(Debug, Clone, Copy)]
 struct FsLoader;

-impl SourceLoader for FsLoader {
+impl ImportLoader for FsLoader {
    fn load(
        &mut self,
        current_key: Option<&str>,
        specifier: &str,
-    ) -> Result<LoadedSource, Diagnostic> {
+    ) -> Result<LoadedImport, Diagnostic> {
        let path = Path::new(specifier);
        let path = if path.is_absolute() {
            PathBuf::from(path)
@@ -102,7 +112,7 @@ impl SourceLoader for FsLoader {
        } else {
            PathBuf::from(path)
        };
-        load_path(&path)
+        load_path(&path).map(LoadedImport::Source)
    }
 }

@@ -139,15 +149,12 @@ fn print_help() {
    println!("  decodal -                  Read DCDL source from stdin");
 }

-fn print_diagnostic(error: &Diagnostic) {
-    eprintln!(
-        "error[{kind:?}] {source}:{start}..{end}: {message}",
-        kind = error.kind,
-        source = error.span.source.0,
-        start = error.span.start,
-        end = error.span.end,
-        message = error.message,
-    );
+fn format_diagnostic_with_root(error: &Diagnostic, root_name: &str) -> String {
+    format_diagnostic_with(error, |source| (source == SourceId(0)).then_some(root_name))
+}
+
+fn format_raw_diagnostic(error: Diagnostic) -> String {
+    format_diagnostic_with(&error, |_| None)
 }

 fn print_data(data: &Data, indent: usize) {
@@ -1,12 +1,21 @@
 [package]
-name = "decodal-core"
-version = "0.1.0"
-edition = "2024"
+name = "decodal"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Parser, evaluator, and embedding API for the Decodal data description language."
+keywords = ["decodal", "dsl", "config", "schema"]
+categories = ["config", "parser-implementations"]

 [features]
 default = ["std"]
 std = []
+derive = ["dep:decodal-derive"]
 regex = ["std", "dep:regex"]

 [dependencies]
+decodal-derive = { version = "0.1.3", path = "../decodal-derive", optional = true }
 regex = { version = "1.10", default-features = false, features = ["std", "unicode-perl"], optional = true }
@@ -1,6 +1,6 @@
-use decodal_core::{Data, EmptyLoader, Engine, HostValue};
+use decodal::{Data, EmptyLoader, Engine, HostValue};

-fn main() -> decodal_core::Result<()> {
+fn main() -> decodal::Result<()> {
    let mut engine = Engine::new(EmptyLoader);

    engine.bind_global(
@@ -0,0 +1,87 @@
+use decodal::{
+    Data, Diagnostic, DiagnosticKind, Engine, HostValue, ImportLoader, LoadedImport, Span,
+};
+
+const POST: &str = r#"---
+title: Hello
+draft: false
+---
+# Hello
+
+This body stays as Markdown.
+"#;
+
+struct ContentLoader;
+
+impl ImportLoader for ContentLoader {
+    fn load(
+        &mut self,
+        _current_key: Option<&str>,
+        specifier: &str,
+    ) -> decodal::Result<LoadedImport> {
+        if specifier != "./post.md" {
+            return Err(Diagnostic::new(
+                DiagnosticKind::Import,
+                Span::default(),
+                format!("unknown content import `{specifier}`"),
+            ));
+        }
+        Ok(LoadedImport::value(
+            "content/post.md",
+            parse_markdown(POST)?,
+        ))
+    }
+}
+
+fn parse_markdown(source: &str) -> decodal::Result<HostValue> {
+    let source = source.strip_prefix("---\n").ok_or_else(frontmatter_error)?;
+    let (frontmatter, body) = source.split_once("\n---\n").ok_or_else(frontmatter_error)?;
+    let mut fields = Vec::new();
+    for line in frontmatter.lines() {
+        let (name, value) = line.split_once(':').ok_or_else(frontmatter_error)?;
+        let value = match value.trim() {
+            "true" => HostValue::bool(true),
+            "false" => HostValue::bool(false),
+            value => HostValue::string(value),
+        };
+        fields.push((name.trim(), value));
+    }
+    Ok(HostValue::object([
+        ("frontmatter", HostValue::object(fields)),
+        ("body", HostValue::string(body)),
+    ]))
+}
+
+fn frontmatter_error() -> Diagnostic {
+    Diagnostic::new(
+        DiagnosticKind::Import,
+        Span::default(),
+        "invalid Markdown frontmatter",
+    )
+}
+
+fn main() -> decodal::Result<()> {
+    let mut engine = Engine::new(ContentLoader);
+    let module = engine.add_root_source(
+        "main.dcdl",
+        "main.dcdl",
+        r#"
+        let post = import "./post.md";
+        in {
+            title = post.frontmatter.title;
+            draft = post.frontmatter.draft;
+            body = post.body;
+        }
+        "#,
+    )?;
+    let value = engine.eval_module(module)?;
+    let data = engine.materialize(&value)?;
+
+    let Data::Object(fields) = data else {
+        panic!("expected imported Markdown to produce an object")
+    };
+    assert_eq!(fields[0].value, Data::String(String::from("Hello")));
+    assert_eq!(fields[1].value, Data::Bool(false));
+    assert!(matches!(fields[2].value, Data::String(_)));
+    Ok(())
+}
@@ -50,6 +50,9 @@ pub enum Expr {
    Ident(String),
    Object(Vec<Field>),
    Array(Vec<ExprId>),
+    ArrayConstraint {
+        item: ExprId,
+    },
    Let {
        bindings: Vec<Field>,
        body: ExprId,
@@ -67,10 +70,21 @@ pub enum Expr {
        params: Vec<Param>,
        body: ExprId,
    },
+    /// An explicitly parenthesized expression.
+    ///
+    /// Keeping this node preserves the delimiters and their trivia for source
+    /// tools while evaluation remains equivalent to evaluating `expr`.
+    Parenthesized {
+        expr: ExprId,
+    },
    Match {
        scrutinee: ExprId,
        arms: Vec<MatchArm>,
    },
+    Unary {
+        op: UnaryOp,
+        expr: ExprId,
+    },
    Binary {
        op: BinaryOp,
        lhs: ExprId,
@@ -117,8 +131,27 @@ pub enum Literal {
    Bool(bool),
 }

+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum UnaryOp {
+    Neg,
+    Not,
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum BinaryOp {
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Concat,
+    Equal,
+    NotEqual,
+    Greater,
+    GreaterEqual,
+    Less,
+    LessEqual,
+    LogicalAnd,
+    LogicalOr,
    And,
    Patch,
 }
@@ -3,103 +3,190 @@ use alloc::{string::String, vec::Vec};
 use crate::{
    Diagnostic, DiagnosticKind, Span,
    ast::CompareOp,
-    runtime::{Constraint, LiteralValue, PrimitiveType},
+    runtime::{Constraint, ConstraintEntry, LiteralValue, PrimitiveType},
 };

 pub fn normalize_constraints(
-    constraints: Vec<Constraint>,
+    constraints: Vec<ConstraintEntry>,
    span: Span,
-) -> crate::Result<Vec<Constraint>> {
-    let mut primitive = None;
-    let mut lower: Option<Bound> = None;
-    let mut upper: Option<Bound> = None;
+) -> crate::Result<Vec<ConstraintEntry>> {
+    let mut primitive: Option<(PrimitiveType, Span)> = None;
+    let mut array_span: Option<Span> = None;
+    let mut lower: Option<(Bound, Span)> = None;
+    let mut upper: Option<(Bound, Span)> = None;
    let mut rest = Vec::new();

-    for constraint in constraints {
-        match constraint {
+    for entry in constraints {
+        match entry.constraint {
            Constraint::Type(next) => match primitive {
-                Some(current) if current != next => {
+                Some((current, current_span)) if current != next => {
                    return Err(Diagnostic::new(
                        DiagnosticKind::Conflict,
                        span,
                        "primitive type constraints conflict",
-                    ));
+                    )
+                    .with_label(current_span, "first primitive constraint")
+                    .with_label(entry.span, "conflicting primitive constraint"));
                }
                Some(_) => {}
-                None => primitive = Some(next),
+                None => primitive = Some((next, entry.span)),
            },
            Constraint::Compare(op, value) => {
                let number = Number::from_literal(&value).ok_or_else(|| {
                    Diagnostic::new(
                        DiagnosticKind::TypeMismatch,
-                        span,
+                        entry.span,
                        "comparison constraints require numeric literals",
                    )
                })?;
                match op {
-                    CompareOp::Gt => merge_lower(&mut lower, Bound::new(number, false)),
-                    CompareOp::Gte => merge_lower(&mut lower, Bound::new(number, true)),
-                    CompareOp::Lt => merge_upper(&mut upper, Bound::new(number, false)),
-                    CompareOp::Lte => merge_upper(&mut upper, Bound::new(number, true)),
+                    CompareOp::Gt => {
+                        merge_lower(&mut lower, (Bound::new(number, false), entry.span))
+                    }
+                    CompareOp::Gte => {
+                        merge_lower(&mut lower, (Bound::new(number, true), entry.span))
+                    }
+                    CompareOp::Lt => {
+                        merge_upper(&mut upper, (Bound::new(number, false), entry.span))
+                    }
+                    CompareOp::Lte => {
+                        merge_upper(&mut upper, (Bound::new(number, true), entry.span))
+                    }
                    CompareOp::Eq => {
-                        merge_lower(&mut lower, Bound::new(number, true));
-                        merge_upper(&mut upper, Bound::new(number, true));
+                        merge_lower(&mut lower, (Bound::new(number, true), entry.span));
+                        merge_upper(&mut upper, (Bound::new(number, true), entry.span));
                    }
                }
            }
-            Constraint::Regex(pattern) => rest.push(Constraint::Regex(pattern)),
-            Constraint::BuiltinPredicate(name) => rest.push(Constraint::BuiltinPredicate(name)),
+            Constraint::Regex(pattern) => rest.push(ConstraintEntry {
+                constraint: Constraint::Regex(pattern),
+                span: entry.span,
+            }),
+            Constraint::ArrayItems(item) => {
+                array_span.get_or_insert(entry.span);
+                rest.push(ConstraintEntry {
+                    constraint: Constraint::ArrayItems(item),
+                    span: entry.span,
+                });
+            }
+            Constraint::BuiltinPredicate(name) => rest.push(ConstraintEntry {
+                constraint: Constraint::BuiltinPredicate(name),
+                span: entry.span,
+            }),
        }
    }

-    if matches!(primitive, Some(PrimitiveType::String | PrimitiveType::Bool))
+    if let (Some((_, primitive_span)), Some(array_span)) = (primitive, array_span) {
+        return Err(Diagnostic::new(
+            DiagnosticKind::Conflict,
+            span,
+            "array element constraints conflict with primitive type constraints",
+        )
+        .with_label(primitive_span, "primitive type constraint")
+        .with_label(array_span, "array element constraint"));
+    }
+
+    if let Some(array_span) = array_span
        && (lower.is_some() || upper.is_some())
    {
-        return Err(Diagnostic::new(
+        let mut diagnostic = Diagnostic::new(
+            DiagnosticKind::Conflict,
+            span,
+            "numeric comparison constraints conflict with array element constraints",
+        )
+        .with_label(array_span, "array element constraint");
+        if let Some((_, lower_span)) = lower {
+            diagnostic = diagnostic.with_label(lower_span, "numeric comparison constraint");
+        }
+        if let Some((_, upper_span)) = upper {
+            diagnostic = diagnostic.with_label(upper_span, "numeric comparison constraint");
+        }
+        return Err(diagnostic);
+    }
+
+    if matches!(
+        primitive,
+        Some((PrimitiveType::String | PrimitiveType::Bool, _))
+    ) && (lower.is_some() || upper.is_some())
+    {
+        let mut diagnostic = Diagnostic::new(
            DiagnosticKind::Conflict,
            span,
            "numeric comparison constraints conflict with non-numeric primitive type",
-        ));
+        );
+        if let Some((_, primitive_span)) = primitive {
+            diagnostic = diagnostic.with_label(primitive_span, "non-numeric primitive constraint");
+        }
+        if let Some((_, lower_span)) = lower {
+            diagnostic = diagnostic.with_label(lower_span, "numeric comparison constraint");
+        }
+        if let Some((_, upper_span)) = upper {
+            diagnostic = diagnostic.with_label(upper_span, "numeric comparison constraint");
+        }
+        return Err(diagnostic);
    }

-    if primitive == Some(PrimitiveType::Int)
+    if matches!(primitive, Some((PrimitiveType::Int, _)))
        && lower
            .iter()
            .chain(upper.iter())
-            .any(|bound| !matches!(bound.number, Number::Int(_)))
+            .any(|(bound, _)| !matches!(bound.number, Number::Int(_)))
    {
-        return Err(Diagnostic::new(
+        let mut diagnostic = Diagnostic::new(
            DiagnosticKind::Conflict,
            span,
            "Int comparison constraints must use integer literals",
-        ));
+        );
+        if let Some((_, primitive_span)) = primitive {
+            diagnostic = diagnostic.with_label(primitive_span, "Int primitive constraint");
+        }
+        if let Some((bound, bound_span)) = lower {
+            if !matches!(bound.number, Number::Int(_)) {
+                diagnostic = diagnostic.with_label(bound_span, "non-integer comparison constraint");
+            }
+        }
+        if let Some((bound, bound_span)) = upper {
+            if !matches!(bound.number, Number::Int(_)) {
+                diagnostic = diagnostic.with_label(bound_span, "non-integer comparison constraint");
+            }
+        }
+        return Err(diagnostic);
    }

    ensure_bounds_non_empty(primitive, lower, upper, span)?;

    let mut normalized = Vec::new();
-    if let Some(primitive) = primitive {
-        normalized.push(Constraint::Type(primitive));
+    if let Some((primitive, primitive_span)) = primitive {
+        normalized.push(ConstraintEntry {
+            constraint: Constraint::Type(primitive),
+            span: primitive_span,
+        });
    }
-    if let Some(lower) = lower {
-        normalized.push(Constraint::Compare(
-            if lower.inclusive {
-                CompareOp::Gte
-            } else {
-                CompareOp::Gt
-            },
-            lower.number.into_literal(),
-        ));
+    if let Some((lower, lower_span)) = lower {
+        normalized.push(ConstraintEntry {
+            constraint: Constraint::Compare(
+                if lower.inclusive {
+                    CompareOp::Gte
+                } else {
+                    CompareOp::Gt
+                },
+                lower.number.into_literal(),
+            ),
+            span: lower_span,
+        });
    }
-    if let Some(upper) = upper {
-        normalized.push(Constraint::Compare(
-            if upper.inclusive {
-                CompareOp::Lte
-            } else {
-                CompareOp::Lt
-            },
-            upper.number.into_literal(),
-        ));
+    if let Some((upper, upper_span)) = upper {
+        normalized.push(ConstraintEntry {
+            constraint: Constraint::Compare(
+                if upper.inclusive {
+                    CompareOp::Lte
+                } else {
+                    CompareOp::Lt
+                },
+                upper.number.into_literal(),
+            ),
+            span: upper_span,
+        });
    }
    normalized.extend(rest);
    Ok(normalized)
@@ -147,18 +234,22 @@ impl Number {
    }
 }

-fn merge_lower(current: &mut Option<Bound>, next: Bound) {
+fn merge_lower(current: &mut Option<(Bound, Span)>, next: (Bound, Span)) {
    match current {
        None => *current = Some(next),
-        Some(current_bound) if is_stricter_lower(next, *current_bound) => *current_bound = next,
+        Some((current_bound, _)) if is_stricter_lower(next.0, *current_bound) => {
+            *current = Some(next)
+        }
        Some(_) => {}
    }
 }

-fn merge_upper(current: &mut Option<Bound>, next: Bound) {
+fn merge_upper(current: &mut Option<(Bound, Span)>, next: (Bound, Span)) {
    match current {
        None => *current = Some(next),
-        Some(current_bound) if is_stricter_upper(next, *current_bound) => *current_bound = next,
+        Some((current_bound, _)) if is_stricter_upper(next.0, *current_bound) => {
+            *current = Some(next)
+        }
        Some(_) => {}
    }
 }
@@ -178,28 +269,32 @@ fn is_stricter_upper(next: Bound, current: Bound) -> bool {
 }

 fn ensure_bounds_non_empty(
-    primitive: Option<PrimitiveType>,
-    lower: Option<Bound>,
-    upper: Option<Bound>,
+    primitive: Option<(PrimitiveType, Span)>,
+    lower: Option<(Bound, Span)>,
+    upper: Option<(Bound, Span)>,
    span: Span,
 ) -> crate::Result<()> {
-    if primitive == Some(PrimitiveType::Int) {
-        let min = lower.map(int_lower_bound).unwrap_or(i128::from(i64::MIN));
-        let max = upper.map(int_upper_bound).unwrap_or(i128::from(i64::MAX));
+    if matches!(primitive, Some((PrimitiveType::Int, _))) {
+        let min = lower
+            .map(|(bound, _)| int_lower_bound(bound))
+            .unwrap_or(i128::from(i64::MIN));
+        let max = upper
+            .map(|(bound, _)| int_upper_bound(bound))
+            .unwrap_or(i128::from(i64::MAX));
        if min > max {
-            return Err(empty_numeric_bounds(span));
+            return Err(empty_numeric_bounds(span, lower, upper));
        }
        return Ok(());
    }

-    if let (Some(lower), Some(upper)) = (lower, upper) {
-        let lower_value = lower.number.as_f64();
-        let upper_value = upper.number.as_f64();
+    if let (Some((lower_bound, _)), Some((upper_bound, _))) = (lower, upper) {
+        let lower_value = lower_bound.number.as_f64();
+        let upper_value = upper_bound.number.as_f64();
        if lower_value > upper_value {
-            return Err(empty_numeric_bounds(span));
+            return Err(empty_numeric_bounds(span, lower, upper));
        }
-        if lower_value == upper_value && !(lower.inclusive && upper.inclusive) {
-            return Err(empty_numeric_bounds(span));
+        if lower_value == upper_value && !(lower_bound.inclusive && upper_bound.inclusive) {
+            return Err(empty_numeric_bounds(span, lower, upper));
        }
    }
    Ok(())
@@ -227,12 +322,23 @@ fn int_upper_bound(bound: Bound) -> i128 {
    }
 }

-fn empty_numeric_bounds(span: Span) -> Diagnostic {
-    Diagnostic::new(
+fn empty_numeric_bounds(
+    span: Span,
+    lower: Option<(Bound, Span)>,
+    upper: Option<(Bound, Span)>,
+) -> Diagnostic {
+    let mut diagnostic = Diagnostic::new(
        DiagnosticKind::Conflict,
        span,
        String::from("numeric comparison constraints have an empty intersection"),
-    )
+    );
+    if let Some((_, lower_span)) = lower {
+        diagnostic = diagnostic.with_label(lower_span, "lower bound constraint");
+    }
+    if let Some((_, upper_span)) = upper {
+        diagnostic = diagnostic.with_label(upper_span, "upper bound constraint");
+    }
+    diagnostic
 }

 #[cfg(test)]
@@ -240,13 +346,20 @@ mod tests {
    use super::*;
    use crate::runtime::LiteralValue;

+    fn entry(constraint: Constraint) -> ConstraintEntry {
+        ConstraintEntry {
+            constraint,
+            span: Span::default(),
+        }
+    }
+
    #[test]
    fn detects_primitive_conflict() {
        assert!(
            normalize_constraints(
                alloc::vec![
-                    Constraint::Type(PrimitiveType::Int),
-                    Constraint::Type(PrimitiveType::String),
+                    entry(Constraint::Type(PrimitiveType::Int)),
+                    entry(Constraint::Type(PrimitiveType::String)),
                ],
                Span::default(),
            )
@@ -259,9 +372,9 @@ mod tests {
        assert!(
            normalize_constraints(
                alloc::vec![
-                    Constraint::Type(PrimitiveType::Int),
-                    Constraint::Compare(CompareOp::Gt, LiteralValue::Int(10)),
-                    Constraint::Compare(CompareOp::Lt, LiteralValue::Int(11)),
+                    entry(Constraint::Type(PrimitiveType::Int)),
+                    entry(Constraint::Compare(CompareOp::Gt, LiteralValue::Int(10))),
+                    entry(Constraint::Compare(CompareOp::Lt, LiteralValue::Int(5))),
                ],
                Span::default(),
            )
@@ -270,15 +383,16 @@ mod tests {
    }

    #[test]
-    fn keeps_regex_constraints_without_intersection_check() {
-        let constraints = normalize_constraints(
-            alloc::vec![
-                Constraint::Regex(String::from("^a$")),
-                Constraint::Regex(String::from("^b$")),
-            ],
-            Span::default(),
-        )
-        .unwrap();
-        assert_eq!(constraints.len(), 2);
+    fn detects_non_integer_int_bound() {
+        assert!(
+            normalize_constraints(
+                alloc::vec![
+                    entry(Constraint::Type(PrimitiveType::Int)),
+                    entry(Constraint::Compare(CompareOp::Gt, LiteralValue::Float(1.5))),
+                ],
+                Span::default(),
+            )
+            .is_err()
+        );
    }
 }
@@ -1,4 +1,4 @@
-use alloc::string::String;
+use alloc::{string::String, vec::Vec};

 use crate::span::Span;

@@ -9,6 +9,14 @@ pub struct Diagnostic {
    pub kind: DiagnosticKind,
    pub span: Span,
    pub message: String,
+    pub labels: Vec<DiagnosticLabel>,
+    pub notes: Vec<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DiagnosticLabel {
+    pub span: Span,
+    pub message: String,
 }

 impl Diagnostic {
@@ -17,12 +25,27 @@ impl Diagnostic {
            kind,
            span,
            message: message.into(),
+            labels: Vec::new(),
+            notes: Vec::new(),
        }
    }

    pub fn syntax(span: Span, message: impl Into<String>) -> Self {
        Self::new(DiagnosticKind::Syntax, span, message)
    }
+
+    pub fn with_label(mut self, span: Span, message: impl Into<String>) -> Self {
+        self.labels.push(DiagnosticLabel {
+            span,
+            message: message.into(),
+        });
+        self
+    }
+
+    pub fn with_note(mut self, message: impl Into<String>) -> Self {
+        self.notes.push(message.into());
+        self
+    }
 }

 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -10,6 +10,11 @@ pub enum HostValue {
    Float(f64),
    Bool(bool),
    Array(Vec<HostValue>),
+    ArrayConstraint {
+        item: Box<HostValue>,
+        constraints: Vec<Constraint>,
+        default: Option<Box<HostValue>>,
+    },
    Object(Vec<HostField>),
    Abstract {
        constraints: Vec<Constraint>,
@@ -63,6 +68,18 @@ impl HostValue {
        )
    }

+    pub fn object_from_paths<I, N>(fields: I) -> Self
+    where
+        I: IntoIterator<Item = (N, HostValue)>,
+        N: Into<String>,
+    {
+        let mut root = Vec::new();
+        for (path, value) in fields {
+            insert_path(&mut root, &path.into(), value);
+        }
+        Self::Object(root)
+    }
+
    pub fn string_type() -> Self {
        Self::abstract_with_constraint(Constraint::Type(PrimitiveType::String))
    }
@@ -79,6 +96,14 @@ impl HostValue {
        Self::abstract_with_constraint(Constraint::Type(PrimitiveType::Bool))
    }

+    pub fn array_of(item: HostValue) -> Self {
+        Self::ArrayConstraint {
+            item: Box::new(item),
+            constraints: Vec::new(),
+            default: None,
+        }
+    }
+
    pub fn builtin_predicate(name: impl Into<String>) -> Self {
        Self::abstract_with_constraint(Constraint::BuiltinPredicate(name.into()))
    }
@@ -93,6 +118,7 @@ impl HostValue {
    pub fn with_constraint(mut self, constraint: Constraint) -> Self {
        match &mut self {
            Self::Abstract { constraints, .. } => constraints.push(constraint),
+            Self::ArrayConstraint { constraints, .. } => constraints.push(constraint),
            _ => {
                self = Self::Abstract {
                    constraints: alloc::vec![constraint],
@@ -127,6 +153,22 @@ impl HostValue {

    pub fn default(self, value: HostValue) -> Result<Self> {
        match self {
+            Self::ArrayConstraint {
+                item,
+                constraints,
+                default: None,
+            } => Ok(Self::ArrayConstraint {
+                item,
+                constraints,
+                default: Some(Box::new(value)),
+            }),
+            Self::ArrayConstraint {
+                default: Some(_), ..
+            } => Err(Diagnostic::new(
+                DiagnosticKind::DefaultConflict,
+                Span::default(),
+                "host value already has a default",
+            )),
            Self::Abstract {
                constraints,
                default: None,
@@ -162,3 +204,38 @@ impl HostValue {
        self.default(Self::bool(value))
    }
 }
+
+impl HostField {
+    pub fn new(name: impl Into<String>, value: HostValue) -> Self {
+        Self {
+            name: name.into(),
+            value,
+        }
+    }
+}
+
+fn insert_path(fields: &mut Vec<HostField>, path: &str, value: HostValue) {
+    let mut parts = path.splitn(2, '.');
+    let Some(head) = parts.next().filter(|part| !part.is_empty()) else {
+        return;
+    };
+    if let Some(tail) = parts.next() {
+        if let Some(field) = fields.iter_mut().find(|field| field.name == head) {
+            if let HostValue::Object(children) = &mut field.value {
+                insert_path(children, tail, value);
+            } else {
+                let mut children = Vec::new();
+                insert_path(&mut children, tail, value);
+                field.value = HostValue::Object(children);
+            }
+        } else {
+            let mut children = Vec::new();
+            insert_path(&mut children, tail, value);
+            fields.push(HostField::new(head, HostValue::Object(children)));
+        }
+    } else if let Some(field) = fields.iter_mut().find(|field| field.name == head) {
+        field.value = value;
+    } else {
+        fields.push(HostField::new(head, value));
+    }
+}
@@ -0,0 +1,34 @@
+use crate::{Engine, ImportLoader, Result};
+
+/// Host-owned configuration shared by runtime and language tooling.
+///
+/// Implementations create the import loader and install global bindings on a
+/// fresh engine. Calling [`HostEnvironment::create_engine`] therefore gives
+/// every consumer the same Decodal execution environment.
+pub trait HostEnvironment {
+    type Loader: ImportLoader;
+
+    fn create_loader(&self) -> Self::Loader;
+
+    fn configure_engine(&self, _engine: &mut Engine<Self::Loader>) -> Result<()> {
+        Ok(())
+    }
+
+    fn create_engine(&self) -> Result<Engine<Self::Loader>> {
+        let mut engine = Engine::new(self.create_loader());
+        self.configure_engine(&mut engine)?;
+        Ok(engine)
+    }
+}
+
+impl<T: HostEnvironment + ?Sized> HostEnvironment for &T {
+    type Loader = T::Loader;
+
+    fn create_loader(&self) -> Self::Loader {
+        T::create_loader(*self)
+    }
+
+    fn configure_engine(&self, engine: &mut Engine<Self::Loader>) -> Result<()> {
+        T::configure_engine(*self, engine)
+    }
+}
@@ -32,18 +32,45 @@ pub enum TokenKind {
    Semicolon,
    Comma,
    Dot,
+    Ellipsis,
    Colon,
    Equal,
+    EqualEqual,
+    Bang,
+    BangEqual,
    Arrow,
    Amp,
+    AmpAmp,
+    PipePipe,
+    Plus,
+    PlusPlus,
+    Minus,
+    Star,
+    Slash,
    SlashSlash,
    Gt,
    Gte,
    Lt,
    Lte,
+    /// A line comment, including its leading `#` and excluding its newline.
+    Comment,
    Eof,
 }

+/// Tokenizes source while retaining comments and source spans for tooling.
+///
+/// Whitespace remains available through the gaps between adjacent token spans,
+/// making this a lossless syntax view when paired with the original source.
+pub fn tokenize_source(source: &str) -> Result<Vec<Token>> {
+    tokenize_source_with_source_id(SourceId(0), source)
+}
+
+/// Tokenizes source with a caller-provided source identifier while retaining
+/// comments and source spans for tooling.
+pub fn tokenize_source_with_source_id(source_id: SourceId, source: &str) -> Result<Vec<Token>> {
+    Lexer::with_source_id(source_id, source).tokenize_with_comments()
+}
+
 pub struct Lexer<'a> {
    source_id: SourceId,
    source: &'a str,
@@ -52,6 +79,7 @@ pub struct Lexer<'a> {
 }

 impl<'a> Lexer<'a> {
+    #[cfg(test)]
    pub fn new(source: &'a str) -> Self {
        Self::with_source_id(SourceId(0), source)
    }
@@ -66,10 +94,30 @@ impl<'a> Lexer<'a> {
    }

    pub fn tokenize(mut self) -> Result<Vec<Token>> {
+        self.tokenize_impl(false)
+    }
+
+    fn tokenize_with_comments(mut self) -> Result<Vec<Token>> {
+        self.tokenize_impl(true)
+    }
+
+    fn tokenize_impl(&mut self, include_comments: bool) -> Result<Vec<Token>> {
        let mut tokens = Vec::new();
+        let mut previous = None;
        loop {
-            let token = self.next_token()?;
+            self.skip_whitespace();
+            if self.peek() == Some(b'#') {
+                let comment = self.lex_comment();
+                if include_comments {
+                    tokens.push(comment);
+                }
+                continue;
+            }
+            let token = self.next_non_ws_token(previous.as_ref())?;
            let is_eof = token.kind == TokenKind::Eof;
+            if !is_eof {
+                previous = Some(token.kind.clone());
+            }
            tokens.push(token);
            if is_eof {
                return Ok(tokens);
@@ -77,8 +125,7 @@ impl<'a> Lexer<'a> {
        }
    }

-    fn next_token(&mut self) -> Result<Token> {
-        self.skip_ws_and_comments();
+    fn next_non_ws_token(&mut self, previous: Option<&TokenKind>) -> Result<Token> {
        let start = self.pos;
        let Some(ch) = self.peek() else {
            return Ok(Token {
@@ -122,7 +169,18 @@ impl<'a> Lexer<'a> {
            }
            b'.' => {
                self.pos += 1;
-                TokenKind::Dot
+                if self.consume(b'.') {
+                    if self.consume(b'.') {
+                        TokenKind::Ellipsis
+                    } else {
+                        return Err(Diagnostic::syntax(
+                            self.span(start, self.pos),
+                            "expected third '.' in ellipsis",
+                        ));
+                    }
+                } else {
+                    TokenKind::Dot
+                }
            }
            b':' => {
                self.pos += 1;
@@ -134,16 +192,57 @@ impl<'a> Lexer<'a> {
            }
            b'&' => {
                self.pos += 1;
-                TokenKind::Amp
+                if self.consume(b'&') {
+                    TokenKind::AmpAmp
+                } else {
+                    TokenKind::Amp
+                }
+            }
+            b'|' => {
+                self.pos += 1;
+                if self.consume(b'|') {
+                    TokenKind::PipePipe
+                } else {
+                    return Err(Diagnostic::syntax(
+                        self.span(start, self.pos),
+                        "expected '|' after '|'",
+                    ));
+                }
+            }
+            b'+' => {
+                self.pos += 1;
+                if self.consume(b'+') {
+                    TokenKind::PlusPlus
+                } else {
+                    TokenKind::Plus
+                }
+            }
+            b'-' => {
+                self.pos += 1;
+                TokenKind::Minus
+            }
+            b'*' => {
+                self.pos += 1;
+                TokenKind::Star
            }
            b'=' => {
                self.pos += 1;
                if self.consume(b'>') {
                    TokenKind::Arrow
+                } else if self.consume(b'=') {
+                    TokenKind::EqualEqual
                } else {
                    TokenKind::Equal
                }
            }
+            b'!' => {
+                self.pos += 1;
+                if self.consume(b'=') {
+                    TokenKind::BangEqual
+                } else {
+                    TokenKind::Bang
+                }
+            }
            b'>' => {
                self.pos += 1;
                if self.consume(b'=') {
@@ -164,6 +263,8 @@ impl<'a> Lexer<'a> {
                self.pos += 1;
                if self.consume(b'/') {
                    TokenKind::SlashSlash
+                } else if previous.is_some_and(token_can_end_expr) {
+                    TokenKind::Slash
                } else {
                    self.lex_regex(start)?
                }
@@ -185,21 +286,23 @@ impl<'a> Lexer<'a> {
        })
    }

-    fn skip_ws_and_comments(&mut self) {
-        loop {
-            while matches!(self.peek(), Some(b' ' | b'\t' | b'\r' | b'\n')) {
-                self.pos += 1;
+    fn skip_whitespace(&mut self) {
+        while matches!(self.peek(), Some(b' ' | b'\t' | b'\r' | b'\n')) {
+            self.pos += 1;
+        }
+    }
+
+    fn lex_comment(&mut self) -> Token {
+        let start = self.pos;
+        while let Some(c) = self.peek() {
+            if c == b'\n' {
+                break;
            }
-            if self.peek() == Some(b'#') {
-                while let Some(c) = self.peek() {
-                    self.pos += 1;
-                    if c == b'\n' {
-                        break;
-                    }
-                }
-                continue;
-            }
-            break;
+            self.pos += 1;
+        }
+        Token {
+            kind: TokenKind::Comment,
+            span: self.span(start, self.pos),
        }
    }

@@ -341,6 +444,23 @@ fn is_ident_continue(c: u8) -> bool {
    c.is_ascii_alphanumeric() || c == b'_'
 }

+fn token_can_end_expr(kind: &TokenKind) -> bool {
+    matches!(
+        kind,
+        TokenKind::Ident(_)
+            | TokenKind::Int(_)
+            | TokenKind::Float(_)
+            | TokenKind::String(_)
+            | TokenKind::Regex(_)
+            | TokenKind::True
+            | TokenKind::False
+            | TokenKind::Underscore
+            | TokenKind::RBrace
+            | TokenKind::RBracket
+            | TokenKind::RParen
+    )
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -353,4 +473,39 @@ mod tests {
        assert_eq!(tokens[3].kind, TokenKind::Amp);
        assert_eq!(tokens[4].kind, TokenKind::Gte);
    }
+
+    #[test]
+    fn tokenizes_array_constraint_ellipsis() {
+        let tokens = Lexer::new("[...String]").tokenize().unwrap();
+        assert_eq!(tokens[0].kind, TokenKind::LBracket);
+        assert_eq!(tokens[1].kind, TokenKind::Ellipsis);
+        assert!(matches!(tokens[2].kind, TokenKind::Ident(_)));
+        assert_eq!(tokens[3].kind, TokenKind::RBracket);
+    }
+
+    #[test]
+    fn tooling_tokens_retain_comments_and_whitespace_gaps() {
+        let source = "value = 1; # trailing\n\n# leading\nnext = 2;";
+        let tokens = tokenize_source(source).unwrap();
+        let comments = tokens
+            .iter()
+            .filter(|token| token.kind == TokenKind::Comment)
+            .collect::<Vec<_>>();
+        assert_eq!(comments.len(), 2);
+        assert_eq!(
+            &source[comments[0].span.start as usize..comments[0].span.end as usize],
+            "# trailing"
+        );
+        assert!(
+            source[comments[0].span.end as usize..comments[1].span.start as usize].contains("\n\n")
+        );
+
+        let source_id = SourceId(7);
+        let identified = tokenize_source_with_source_id(source_id, "# comment").unwrap();
+        assert!(
+            identified
+                .iter()
+                .all(|token| token.span.source == source_id)
+        );
+    }
 }
@@ -6,23 +6,37 @@ pub mod ast;
 pub mod constraints;
 pub mod diagnostic;
 pub mod embedding;
+pub mod environment;
 pub mod eval;
-pub mod lexer;
+mod lexer;
 pub mod module;
 pub mod parser;
 pub mod runtime;
 pub mod span;
+pub mod typed;

 pub use ast::{Ast, BinaryOp, CompareOp, Expr, ExprId, Field, Literal, Param};
 pub use constraints::normalize_constraints;
+#[cfg(feature = "derive")]
+pub use decodal_derive::Decodal;
 pub use diagnostic::{Diagnostic, DiagnosticKind, Result};
 pub use embedding::{HostField, HostValue};
-pub use eval::Engine;
-pub use lexer::{Lexer, Token, TokenKind};
-pub use module::{EmptyLoader, LoadedSource, Module, SourceLoader};
+pub use environment::HostEnvironment;
+pub use eval::{Engine, format_diagnostic_with};
+pub use lexer::{
+    Token as SyntaxToken, TokenKind as SyntaxTokenKind, tokenize_source,
+    tokenize_source_with_source_id,
+};
+pub use module::{
+    EmptyLoader, ImportCandidate, ImportLoader, LoadedImport, LoadedSource, LoadedValue, Module,
+};
 pub use parser::{ParseOutput, Parser, SourceForm, parse_source, parse_source_with_source_id};
 pub use runtime::{Constraint, Data, ExprRef, LiteralValue, ModuleId, PrimitiveType, RuntimeValue};
 pub use span::{SourceId, Span};
+pub use typed::{
+    DecodalDecode, DecodalSchema, DecodeError, DecodeResult, IntoHostValue, data_at_path,
+    decode_path, prefix_decode_error,
+};

 pub fn version() -> &'static str {
    env!("CARGO_PKG_VERSION")
@@ -1,7 +1,7 @@
-use alloc::string::String;
+use alloc::{string::String, vec::Vec};

 use crate::{
-    Ast, ExprId, SourceForm, SourceId,
+    Ast, ExprId, HostValue, SourceForm, SourceId,
    runtime::{EnvId, ThunkId},
 };

@@ -24,15 +24,82 @@ pub struct LoadedSource {
    pub source: String,
 }

-pub trait SourceLoader {
-    fn load(&mut self, current_key: Option<&str>, specifier: &str) -> crate::Result<LoadedSource>;
+#[derive(Debug, Clone)]
+pub struct LoadedValue {
+    pub key: String,
+    pub value: HostValue,
+}
+
+#[derive(Debug, Clone)]
+pub enum LoadedImport {
+    Source(LoadedSource),
+    Value(LoadedValue),
+}
+
+/// An import specifier offered by host-owned language tooling.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ImportCandidate {
+    pub specifier: String,
+    pub detail: Option<String>,
+}
+
+impl ImportCandidate {
+    pub fn new(specifier: impl Into<String>) -> Self {
+        Self {
+            specifier: specifier.into(),
+            detail: None,
+        }
+    }
+
+    pub fn with_detail(mut self, detail: impl Into<String>) -> Self {
+        self.detail = Some(detail.into());
+        self
+    }
+}
+
+impl LoadedImport {
+    pub fn source(
+        key: impl Into<String>,
+        name: impl Into<String>,
+        source: impl Into<String>,
+    ) -> Self {
+        Self::Source(LoadedSource {
+            key: key.into(),
+            name: name.into(),
+            source: source.into(),
+        })
+    }
+
+    pub fn value(key: impl Into<String>, value: HostValue) -> Self {
+        Self::Value(LoadedValue {
+            key: key.into(),
+            value,
+        })
+    }
+}
+
+pub trait ImportLoader {
+    fn load(&mut self, current_key: Option<&str>, specifier: &str) -> crate::Result<LoadedImport>;
+
+    /// Returns host-resolvable import specifiers matching an unfinished prefix.
+    ///
+    /// Runtime-only loaders may keep the default implementation. Hosts that
+    /// provide an editor should implement this from the same namespace used by
+    /// [`ImportLoader::load`].
+    fn complete_import(
+        &mut self,
+        _current_key: Option<&str>,
+        _prefix: &str,
+    ) -> crate::Result<Vec<ImportCandidate>> {
+        Ok(Vec::new())
+    }
 }

 #[derive(Debug, Clone, Copy, Default)]
 pub struct EmptyLoader;

-impl SourceLoader for EmptyLoader {
-    fn load(&mut self, _current_key: Option<&str>, specifier: &str) -> crate::Result<LoadedSource> {
+impl ImportLoader for EmptyLoader {
+    fn load(&mut self, _current_key: Option<&str>, specifier: &str) -> crate::Result<LoadedImport> {
        Err(crate::Diagnostic::new(
            crate::DiagnosticKind::Import,
            crate::Span::default(),
@@ -2,7 +2,7 @@ use alloc::{string::String, vec::Vec};

 use crate::{
    SourceId, Span,
-    ast::{Ast, BinaryOp, CompareOp, Expr, ExprId, Field, Literal, MatchArm, Param},
+    ast::{Ast, BinaryOp, CompareOp, Expr, ExprId, Field, Literal, MatchArm, Param, UnaryOp},
    diagnostic::{Diagnostic, Result},
    lexer::{Lexer, Token, TokenKind},
 };
@@ -38,7 +38,10 @@ pub struct Parser {
 impl Parser {
    pub fn new(tokens: Vec<Token>) -> Self {
        Self {
-            tokens,
+            tokens: tokens
+                .into_iter()
+                .filter(|token| token.kind != TokenKind::Comment)
+                .collect(),
            pos: 0,
            ast: Ast::new(),
        }
@@ -115,6 +118,110 @@ impl Parser {
            let rhs = self.parse_expr(r_bp)?;
            let span = self.ast.span(lhs).join(self.ast.span(rhs)).join(op_span);
            lhs = match kind {
+                InfixKind::Add => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Add,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Sub => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Sub,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Mul => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Mul,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Div => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Div,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Concat => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Concat,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Equal => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Equal,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::NotEqual => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::NotEqual,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Greater => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Greater,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::GreaterEqual => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::GreaterEqual,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::Less => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::Less,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::LessEqual => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::LessEqual,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::LogicalAnd => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::LogicalAnd,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
+                InfixKind::LogicalOr => self.ast.push(
+                    Expr::Binary {
+                        op: BinaryOp::LogicalOr,
+                        lhs,
+                        rhs,
+                    },
+                    span,
+                ),
                InfixKind::And => self.ast.push(
                    Expr::Binary {
                        op: BinaryOp::And,
@@ -173,6 +280,28 @@ impl Parser {
            TokenKind::Let => self.parse_let(token.span),
            TokenKind::Match => self.parse_match(token.span),
            TokenKind::Import => self.parse_import(token.span),
+            TokenKind::Minus => {
+                let expr = self.parse_expr(17)?;
+                let span = token.span.join(self.ast.span(expr));
+                Ok(self.ast.push(
+                    Expr::Unary {
+                        op: UnaryOp::Neg,
+                        expr,
+                    },
+                    span,
+                ))
+            }
+            TokenKind::Bang => {
+                let expr = self.parse_expr(17)?;
+                let span = token.span.join(self.ast.span(expr));
+                Ok(self.ast.push(
+                    Expr::Unary {
+                        op: UnaryOp::Not,
+                        expr,
+                    },
+                    span,
+                ))
+            }
            TokenKind::Gt | TokenKind::Gte | TokenKind::Lt | TokenKind::Lte => {
                let op = match token.kind {
                    TokenKind::Gt => CompareOp::Gt,
@@ -181,7 +310,7 @@ impl Parser {
                    TokenKind::Lte => CompareOp::Lte,
                    _ => unreachable!(),
                };
-                let value = self.parse_expr(8)?;
+                let value = self.parse_expr(12)?;
                let span = token.span.join(self.ast.span(value));
                Ok(self.ast.push(Expr::CompareConstraint { op, value }, span))
            }
@@ -212,6 +341,17 @@ impl Parser {
    }

    fn parse_array_after_lbracket(&mut self, start_span: Span) -> Result<ExprId> {
+        if self.consume_kind(&TokenKind::Ellipsis).is_some() {
+            let item = self.parse_expr(0)?;
+            let _ = self.consume_kind(&TokenKind::Comma);
+            self.expect_kind(
+                &TokenKind::RBracket,
+                "expected ']' after array element constraint",
+            )?;
+            let span = start_span.join(self.previous_span());
+            return Ok(self.ast.push(Expr::ArrayConstraint { item }, span));
+        }
+
        let mut items = Vec::new();
        if self.consume_kind(&TokenKind::RBracket).is_some() {
            return Ok(self
@@ -243,8 +383,9 @@ impl Parser {
        }

        let expr = self.parse_expr(0)?;
-        self.expect_kind(&TokenKind::RParen, "expected ')' after expression")?;
-        Ok(expr)
+        let end_span = self.expect_kind(&TokenKind::RParen, "expected ')' after expression")?;
+        let span = start_span.join(end_span);
+        Ok(self.ast.push(Expr::Parenthesized { expr }, span))
    }

    fn parse_params_after_lparen(&mut self) -> Result<Vec<Param>> {
@@ -406,6 +547,19 @@ impl Parser {
            TokenKind::Default => Some((InfixKind::Default, 1, 2)),
            TokenKind::SlashSlash => Some((InfixKind::Patch, 3, 4)),
            TokenKind::Amp => Some((InfixKind::And, 5, 6)),
+            TokenKind::PipePipe => Some((InfixKind::LogicalOr, 7, 8)),
+            TokenKind::AmpAmp => Some((InfixKind::LogicalAnd, 9, 10)),
+            TokenKind::EqualEqual => Some((InfixKind::Equal, 11, 12)),
+            TokenKind::BangEqual => Some((InfixKind::NotEqual, 11, 12)),
+            TokenKind::Gt => Some((InfixKind::Greater, 11, 12)),
+            TokenKind::Gte => Some((InfixKind::GreaterEqual, 11, 12)),
+            TokenKind::Lt => Some((InfixKind::Less, 11, 12)),
+            TokenKind::Lte => Some((InfixKind::LessEqual, 11, 12)),
+            TokenKind::PlusPlus => Some((InfixKind::Concat, 12, 13)),
+            TokenKind::Plus => Some((InfixKind::Add, 13, 14)),
+            TokenKind::Minus => Some((InfixKind::Sub, 13, 14)),
+            TokenKind::Star => Some((InfixKind::Mul, 15, 16)),
+            TokenKind::Slash => Some((InfixKind::Div, 15, 16)),
            _ => None,
        }
    }
@@ -498,6 +652,19 @@ impl Parser {

 #[derive(Debug, Clone, Copy)]
 enum InfixKind {
+    Add,
+    Sub,
+    Mul,
+    Div,
+    Concat,
+    Equal,
+    NotEqual,
+    Greater,
+    GreaterEqual,
+    Less,
+    LessEqual,
+    LogicalAnd,
+    LogicalOr,
    And,
    Patch,
    Default,
@@ -522,4 +689,35 @@ mod tests {
        };
        assert_eq!(fields[0].path, ["feature", "enable"]);
    }
+
+    #[test]
+    fn parses_array_constraint() {
+        let parsed = parse_source("[...(String & /^api-/)]").unwrap();
+        let Expr::ArrayConstraint { item } = parsed.ast.get(parsed.root).expr else {
+            panic!()
+        };
+        let Expr::Parenthesized { expr } = parsed.ast.get(item).expr else {
+            panic!()
+        };
+        assert!(matches!(parsed.ast.get(expr).expr, Expr::Binary { .. }));
+        assert_eq!(parsed.ast.span(item), Span::new(SourceId(0), 4, 22));
+    }
+
+    #[test]
+    fn parser_accepts_the_public_lossless_token_stream() {
+        let tokens = crate::tokenize_source("value = (# note\n 1);").unwrap();
+        let parsed = Parser::new(tokens).parse().unwrap();
+        let Expr::Object(fields) = &parsed.ast.get(parsed.root).expr else {
+            panic!()
+        };
+        assert!(matches!(
+            parsed.ast.get(fields[0].value).expr,
+            Expr::Parenthesized { .. }
+        ));
+    }
+
+    #[test]
+    fn rejects_array_constraint_without_element_constraint() {
+        assert!(parse_source("[...]").is_err());
+    }
 }
@@ -1,6 +1,6 @@
 use alloc::{string::String, vec::Vec};

-use crate::{ExprId, ast::CompareOp};
+use crate::{ExprId, Span, ast::CompareOp};

 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct ModuleId(pub u32);
@@ -37,6 +37,7 @@ pub struct ObjectValue {
 pub struct ObjectField {
    pub name: String,
    pub value: ThunkId,
+    pub span: Span,
 }

 #[derive(Debug, Clone, PartialEq)]
@@ -54,13 +55,20 @@ pub struct FunctionParam {

 #[derive(Debug, Clone, PartialEq)]
 pub struct AbstractValue {
-    pub constraints: Vec<Constraint>,
+    pub constraints: Vec<ConstraintEntry>,
    pub default: Option<ThunkId>,
 }

+#[derive(Debug, Clone, PartialEq)]
+pub struct ConstraintEntry {
+    pub constraint: Constraint,
+    pub span: Span,
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub enum Constraint {
    Type(PrimitiveType),
+    ArrayItems(ThunkId),
    Compare(CompareOp, LiteralValue),
    Regex(String),
    BuiltinPredicate(String),
@@ -108,6 +116,7 @@ pub struct EnvId(pub u32);
 pub struct Thunk {
    pub kind: ThunkKind,
    pub state: ThunkState,
+    pub span: Span,
 }

 #[derive(Debug, Clone)]
@@ -0,0 +1,227 @@
+use alloc::{format, string::String, vec::Vec};
+
+use crate::{Data, HostValue};
+
+pub trait DecodalSchema {
+    fn decodal_schema() -> HostValue;
+}
+
+pub trait DecodalDecode: Sized {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self>;
+}
+
+pub trait IntoHostValue {
+    fn into_host_value(self) -> HostValue;
+}
+
+pub type DecodeResult<T> = core::result::Result<T, DecodeError>;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DecodeError {
+    pub path: String,
+    pub message: String,
+}
+
+impl DecodeError {
+    pub fn new(path: impl Into<String>, message: impl Into<String>) -> Self {
+        Self {
+            path: path.into(),
+            message: message.into(),
+        }
+    }
+
+    pub fn at_type(path: &str, expected: &'static str) -> Self {
+        Self::new(path, format!("expected {expected}"))
+    }
+}
+
+impl core::fmt::Display for DecodeError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        if self.path.is_empty() {
+            write!(f, "{}", self.message)
+        } else {
+            write!(f, "{}: {}", self.path, self.message)
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+impl std::error::Error for DecodeError {}
+
+pub fn decode_path<T: DecodalDecode>(data: &Data, path: &str) -> DecodeResult<T> {
+    let value = data_at_path(data, path).ok_or_else(|| DecodeError::new(path, "missing field"))?;
+    T::decodal_decode(value).map_err(|error| prefix_error(path, error))
+}
+
+pub fn data_at_path<'a>(data: &'a Data, path: &str) -> Option<&'a Data> {
+    let mut current = data;
+    for part in path.split('.') {
+        if part.is_empty() {
+            return None;
+        }
+        let Data::Object(fields) = current else {
+            return None;
+        };
+        current = &fields.iter().find(|field| field.name == part)?.value;
+    }
+    Some(current)
+}
+
+pub fn prefix_decode_error(path: &str, error: DecodeError) -> DecodeError {
+    prefix_error(path, error)
+}
+
+fn prefix_error(path: &str, mut error: DecodeError) -> DecodeError {
+    if error.path.is_empty() {
+        error.path = String::from(path);
+    } else if !path.is_empty() {
+        error.path = format!("{path}.{}", error.path);
+    }
+    error
+}
+
+impl DecodalSchema for String {
+    fn decodal_schema() -> HostValue {
+        HostValue::string_type()
+    }
+}
+
+impl DecodalDecode for String {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+        match data {
+            Data::String(value) => Ok(value.clone()),
+            _ => Err(DecodeError::at_type("", "String")),
+        }
+    }
+}
+
+impl IntoHostValue for String {
+    fn into_host_value(self) -> HostValue {
+        HostValue::string(self)
+    }
+}
+
+impl IntoHostValue for &str {
+    fn into_host_value(self) -> HostValue {
+        HostValue::string(self)
+    }
+}
+
+macro_rules! impl_int_decode {
+    ($($ty:ty),* $(,)?) => {
+        $(
+            impl DecodalSchema for $ty {
+                fn decodal_schema() -> HostValue {
+                    HostValue::int_type()
+                }
+            }
+
+            impl DecodalDecode for $ty {
+                fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+                    match data {
+                        Data::Int(value) => <$ty>::try_from(*value)
+                            .map_err(|_| DecodeError::new("", "integer value is out of range")),
+                        _ => Err(DecodeError::at_type("", "Int")),
+                    }
+                }
+            }
+
+            impl IntoHostValue for $ty {
+                fn into_host_value(self) -> HostValue {
+                    HostValue::int(self as i64)
+                }
+            }
+        )*
+    };
+}
+
+impl_int_decode!(i8, i16, i32, i64, u8, u16, u32);
+
+impl DecodalSchema for f64 {
+    fn decodal_schema() -> HostValue {
+        HostValue::float_type()
+    }
+}
+
+impl DecodalDecode for f64 {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+        match data {
+            Data::Float(value) => Ok(*value),
+            Data::Int(value) => Ok(*value as f64),
+            _ => Err(DecodeError::at_type("", "Float")),
+        }
+    }
+}
+
+impl IntoHostValue for f64 {
+    fn into_host_value(self) -> HostValue {
+        HostValue::float(self)
+    }
+}
+
+impl DecodalSchema for f32 {
+    fn decodal_schema() -> HostValue {
+        HostValue::float_type()
+    }
+}
+
+impl DecodalDecode for f32 {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+        f64::decodal_decode(data).map(|value| value as f32)
+    }
+}
+
+impl IntoHostValue for f32 {
+    fn into_host_value(self) -> HostValue {
+        HostValue::float(f64::from(self))
+    }
+}
+
+impl DecodalSchema for bool {
+    fn decodal_schema() -> HostValue {
+        HostValue::bool_type()
+    }
+}
+
+impl DecodalDecode for bool {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+        match data {
+            Data::Bool(value) => Ok(*value),
+            _ => Err(DecodeError::at_type("", "Bool")),
+        }
+    }
+}
+
+impl IntoHostValue for bool {
+    fn into_host_value(self) -> HostValue {
+        HostValue::bool(self)
+    }
+}
+
+impl<T: DecodalSchema> DecodalSchema for Vec<T> {
+    fn decodal_schema() -> HostValue {
+        HostValue::array_of(T::decodal_schema())
+    }
+}
+
+impl<T: DecodalDecode> DecodalDecode for Vec<T> {
+    fn decodal_decode(data: &Data) -> DecodeResult<Self> {
+        match data {
+            Data::Array(items) => items
+                .iter()
+                .enumerate()
+                .map(|(index, item)| {
+                    T::decodal_decode(item)
+                        .map_err(|error| prefix_error(&format!("[{index}]"), error))
+                })
+                .collect(),
+            _ => Err(DecodeError::at_type("", "Array")),
+        }
+    }
+}
+
+impl<T: IntoHostValue> IntoHostValue for Vec<T> {
+    fn into_host_value(self) -> HostValue {
+        HostValue::array(self.into_iter().map(IntoHostValue::into_host_value))
+    }
+}
@@ -0,0 +1,22 @@
+[package]
+name = "decodal-derive"
+version = "0.1.3"
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Derive macro for generating Decodal schemas and typed decoders from Rust structs."
+keywords = ["decodal", "derive", "proc-macro", "schema"]
+categories = ["config", "development-tools::procedural-macro-helpers"]
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1"
+quote = "1"
+syn = { version = "2", features = ["full"] }
+
+[dev-dependencies]
+decodal = { version = "0.2.0", path = "../decodal-core" }
@@ -0,0 +1,212 @@
+use proc_macro::TokenStream;
+use proc_macro2::TokenStream as TokenStream2;
+use quote::{format_ident, quote};
+use syn::{
+    Data, DeriveInput, Expr, Fields, LitStr, Result, Type, parse_macro_input, spanned::Spanned,
+};
+
+#[proc_macro_derive(Decodal, attributes(decodal))]
+pub fn derive_decodal(input: TokenStream) -> TokenStream {
+    match expand_decodal(parse_macro_input!(input as DeriveInput)) {
+        Ok(tokens) => tokens.into(),
+        Err(error) => error.to_compile_error().into(),
+    }
+}
+
+fn expand_decodal(input: DeriveInput) -> Result<TokenStream2> {
+    let name = input.ident;
+    let fields = match input.data {
+        Data::Struct(data) => match data.fields {
+            Fields::Named(fields) => fields.named,
+            _ => {
+                return Err(syn::Error::new(
+                    data.struct_token.span(),
+                    "Decodal derive supports structs with named fields only",
+                ));
+            }
+        },
+        _ => {
+            return Err(syn::Error::new(
+                name.span(),
+                "Decodal derive supports structs only",
+            ));
+        }
+    };
+
+    let mut schema_fields = Vec::new();
+    let mut decode_fields = Vec::new();
+
+    for field in fields {
+        let ident = field.ident.expect("named field");
+        let ty = field.ty;
+        let attrs = FieldAttrs::from_attrs(&field.attrs, &ident.to_string())?;
+        let path = attrs.rename.clone();
+        let schema_value = schema_expr(&ty, &attrs)?;
+        let decode_value = decode_expr(&ty, &path, &attrs);
+
+        schema_fields.push(quote! {
+            (#path, { #schema_value })
+        });
+        decode_fields.push(quote! {
+            #ident: #decode_value
+        });
+    }
+
+    let (impl_generics, ty_generics, where_clause) = input.generics.split_for_impl();
+
+    Ok(quote! {
+        impl #impl_generics ::decodal::DecodalSchema for #name #ty_generics #where_clause {
+            fn decodal_schema() -> ::decodal::HostValue {
+                ::decodal::HostValue::object_from_paths([
+                    #(#schema_fields),*
+                ])
+            }
+        }
+
+        impl #impl_generics ::decodal::DecodalDecode for #name #ty_generics #where_clause {
+            fn decodal_decode(data: &::decodal::Data) -> ::decodal::DecodeResult<Self> {
+                Ok(Self {
+                    #(#decode_fields),*
+                })
+            }
+        }
+    })
+}
+
+#[derive(Default)]
+struct FieldAttrs {
+    rename: String,
+    default: Option<DefaultAttr>,
+    constraints: Vec<ConstraintAttr>,
+}
+
+impl FieldAttrs {
+    fn from_attrs(attrs: &[syn::Attribute], fallback_name: &str) -> Result<Self> {
+        let mut output = Self {
+            rename: fallback_name.to_string(),
+            ..Self::default()
+        };
+
+        for attr in attrs {
+            if !attr.path().is_ident("decodal") {
+                continue;
+            }
+            attr.parse_nested_meta(|meta| {
+                if meta.path.is_ident("rename") {
+                    let value: LitStr = meta.value()?.parse()?;
+                    output.rename = value.value();
+                    return Ok(());
+                }
+                if meta.path.is_ident("default") {
+                    if meta.input.peek(syn::Token![=]) {
+                        let expr: Expr = meta.value()?.parse()?;
+                        output.default = Some(DefaultAttr::Expr(expr));
+                    } else {
+                        output.default = Some(DefaultAttr::Default);
+                    }
+                    return Ok(());
+                }
+                if let Some(kind) = ConstraintKind::from_path(&meta.path) {
+                    let expr: Expr = meta.value()?.parse()?;
+                    output.constraints.push(ConstraintAttr { kind, expr });
+                    return Ok(());
+                }
+                Err(meta.error("unsupported decodal attribute"))
+            })?;
+        }
+
+        Ok(output)
+    }
+}
+
+enum DefaultAttr {
+    Default,
+    Expr(Expr),
+}
+
+struct ConstraintAttr {
+    kind: ConstraintKind,
+    expr: Expr,
+}
+
+#[derive(Clone, Copy)]
+enum ConstraintKind {
+    Gt,
+    Gte,
+    Lt,
+    Lte,
+}
+
+impl ConstraintKind {
+    fn from_path(path: &syn::Path) -> Option<Self> {
+        if path.is_ident("gt") {
+            Some(Self::Gt)
+        } else if path.is_ident("gte") {
+            Some(Self::Gte)
+        } else if path.is_ident("lt") {
+            Some(Self::Lt)
+        } else if path.is_ident("lte") {
+            Some(Self::Lte)
+        } else {
+            None
+        }
+    }
+
+    fn method(self) -> syn::Ident {
+        match self {
+            Self::Gt => format_ident!("gt"),
+            Self::Gte => format_ident!("gte"),
+            Self::Lt => format_ident!("lt"),
+            Self::Lte => format_ident!("lte"),
+        }
+    }
+}
+
+fn schema_expr(ty: &Type, attrs: &FieldAttrs) -> Result<TokenStream2> {
+    let mut tokens = quote! {
+        let mut schema = <#ty as ::decodal::DecodalSchema>::decodal_schema();
+    };
+
+    for constraint in &attrs.constraints {
+        let method = constraint.kind.method();
+        let expr = &constraint.expr;
+        tokens.extend(quote! {
+            schema = schema.#method(#expr);
+        });
+    }
+
+    if let Some(default) = &attrs.default {
+        let default_expr = match default {
+            DefaultAttr::Default => quote! { <#ty as ::core::default::Default>::default() },
+            DefaultAttr::Expr(expr) => quote! { (#expr) },
+        };
+        tokens.extend(quote! {
+            schema = schema
+                .default(::decodal::IntoHostValue::into_host_value(#default_expr))
+                .expect("Decodal derive generated a valid default");
+        });
+    }
+
+    tokens.extend(quote! { schema });
+    Ok(tokens)
+}
+
+fn decode_expr(ty: &Type, path: &str, attrs: &FieldAttrs) -> TokenStream2 {
+    let missing = if let Some(default) = &attrs.default {
+        match default {
+            DefaultAttr::Default => quote! { <#ty as ::core::default::Default>::default() },
+            DefaultAttr::Expr(expr) => quote! { ::core::convert::Into::into(#expr) },
+        }
+    } else {
+        quote! { return Err(::decodal::DecodeError::new(#path, "missing field")); }
+    };
+
+    quote! {
+        if let Some(value) = ::decodal::data_at_path(data, #path) {
+            <#ty as ::decodal::DecodalDecode>::decodal_decode(value)
+                .map_err(|error| ::decodal::prefix_decode_error(#path, error))?
+        } else {
+            #missing
+        }
+    }
+}
@@ -0,0 +1,150 @@
+use decodal::{Data, DecodalDecode, DecodalSchema, EmptyLoader, Engine};
+use decodal_derive::Decodal;
+
+#[derive(Debug, PartialEq, Decodal)]
+struct Service {
+    name: String,
+    #[decodal(gt = 443, default = 8443)]
+    port: i64,
+    #[decodal(default = true, rename = "feature.enable")]
+    feature_enabled: bool,
+    #[decodal(default)]
+    tags: Vec<String>,
+}
+
+#[derive(Debug, PartialEq, Decodal)]
+struct Worker {
+    name: String,
+    #[decodal(default = true)]
+    enabled: bool,
+}
+
+#[derive(Debug, PartialEq, Decodal)]
+struct Fleet {
+    workers: Vec<Worker>,
+}
+
+#[test]
+fn derives_schema_and_decode() {
+    let mut engine = Engine::new(EmptyLoader);
+    engine
+        .bind_global("Service", Service::decodal_schema())
+        .unwrap();
+    let module = engine
+        .add_root_source(
+            "test",
+            "test",
+            r#"
+            Service & {
+              name = "api";
+              port = 9443;
+              feature.enable = false;
+              tags = ["web", "prod"];
+            }
+            "#,
+        )
+        .unwrap();
+    let value = engine.eval_module(module).unwrap();
+    let data = engine.materialize(&value).unwrap();
+    let service = Service::decodal_decode(&data).unwrap();
+    assert_eq!(
+        service,
+        Service {
+            name: "api".into(),
+            port: 9443,
+            feature_enabled: false,
+            tags: vec!["web".into(), "prod".into()],
+        }
+    );
+}
+
+#[test]
+fn defaults_are_available_in_schema() {
+    let mut engine = Engine::new(EmptyLoader);
+    engine
+        .bind_global("Service", Service::decodal_schema())
+        .unwrap();
+    let module = engine
+        .add_root_source(
+            "test",
+            "test",
+            r#"
+            Service & {
+              name = "api";
+            }
+            "#,
+        )
+        .unwrap();
+    let value = engine.eval_module(module).unwrap();
+    let data = engine.materialize(&value).unwrap();
+    let service = Service::decodal_decode(&data).unwrap();
+    assert_eq!(service.port, 8443);
+    assert!(service.feature_enabled);
+    assert!(service.tags.is_empty());
+}
+
+#[test]
+fn decode_reports_field_path() {
+    let data = Data::Object(vec![]);
+    let error = Service::decodal_decode(&data).unwrap_err();
+    assert_eq!(error.path, "name");
+}
+
+#[test]
+fn vec_schema_rejects_invalid_element_before_decode() {
+    let mut engine = Engine::new(EmptyLoader);
+    engine
+        .bind_global("Service", Service::decodal_schema())
+        .unwrap();
+    let module = engine
+        .add_root_source(
+            "test",
+            "test",
+            r#"
+            Service & {
+              name = "api";
+              port = 9443;
+              tags = ["web", 1];
+            }
+            "#,
+        )
+        .unwrap();
+    let error = engine.eval_module(module).unwrap_err();
+    assert!(
+        error
+            .labels
+            .iter()
+            .any(|label| label.message.contains("array element [1]"))
+    );
+}
+
+#[test]
+fn vec_schema_applies_nested_struct_defaults() {
+    let mut engine = Engine::new(EmptyLoader);
+    engine
+        .bind_global("Fleet", Fleet::decodal_schema())
+        .unwrap();
+    let module = engine
+        .add_root_source(
+            "test",
+            "test",
+            r#"
+            Fleet & {
+              workers = [{ name = "api"; }];
+            }
+            "#,
+        )
+        .unwrap();
+    let value = engine.eval_module(module).unwrap();
+    let data = engine.materialize(&value).unwrap();
+    let fleet = Fleet::decodal_decode(&data).unwrap();
+    assert_eq!(
+        fleet,
+        Fleet {
+            workers: vec![Worker {
+                name: "api".into(),
+                enabled: true,
+            }],
+        }
+    );
+}
@@ -0,0 +1,14 @@
+[package]
+name = "decodal-language-service"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Host-configurable semantic language service for Decodal."
+keywords = ["decodal", "lsp", "language-server", "editor"]
+categories = ["development-tools", "text-editors"]
+
+[dependencies]
+decodal = { version = "0.2.0", path = "../decodal-core" }
@@ -0,0 +1,905 @@
+use std::collections::{BTreeMap, HashMap};
+
+use decodal::{
+    Engine, HostEnvironment, HostValue, ImportLoader, LoadedImport, Result, RuntimeValue,
+};
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CompletionKind {
+    Keyword,
+    Constant,
+    Type,
+    Variable,
+    Namespace,
+    Property,
+    File,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CompletionItem {
+    pub label: String,
+    pub kind: CompletionKind,
+    pub detail: Option<String>,
+    pub priority: i32,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CompletionResult {
+    /// UTF-8 byte offset at which the unfinished token starts.
+    pub from: usize,
+    pub items: Vec<CompletionItem>,
+}
+
+#[derive(Debug, Clone, Default, PartialEq, Eq)]
+struct FieldTree(BTreeMap<String, FieldTree>);
+
+impl FieldTree {
+    fn new() -> Self {
+        Self::default()
+    }
+
+    fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    fn insert(&mut self, name: String, fields: FieldTree) {
+        self.0.insert(name, fields);
+    }
+
+    fn get(&self, name: &str) -> Option<&FieldTree> {
+        self.0.get(name)
+    }
+
+    fn remove(&mut self, name: &str) -> Option<FieldTree> {
+        self.0.remove(name)
+    }
+}
+
+impl IntoIterator for FieldTree {
+    type Item = (String, FieldTree);
+    type IntoIter = std::collections::btree_map::IntoIter<String, FieldTree>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        self.0.into_iter()
+    }
+}
+
+impl FromIterator<(String, FieldTree)> for FieldTree {
+    fn from_iter<T: IntoIterator<Item = (String, FieldTree)>>(iter: T) -> Self {
+        Self(iter.into_iter().collect())
+    }
+}
+
+pub(crate) fn complete<E: HostEnvironment>(
+    environment: &E,
+    key: &str,
+    source: &str,
+    position: usize,
+    explicit: bool,
+) -> Result<Option<CompletionResult>> {
+    let position = floor_char_boundary(source, position.min(source.len()));
+    if let Some((from, prefix)) = unfinished_import(source, position) {
+        let mut loader = environment.create_loader();
+        let items = loader
+            .complete_import(Some(key), prefix)?
+            .into_iter()
+            .map(|candidate| CompletionItem {
+                label: candidate.specifier,
+                kind: CompletionKind::File,
+                detail: candidate.detail,
+                priority: 30,
+            })
+            .collect();
+        return Ok(Some(CompletionResult {
+            from,
+            items: unique_items(items),
+        }));
+    }
+
+    if in_string_or_comment(source, position) {
+        return Ok(None);
+    }
+
+    let tokens = tokenize(source);
+    let local_fields = collect_fields(&tokens);
+    let imports = collect_import_bindings(&tokens);
+    let globals = collect_globals(environment)?;
+
+    if let Some((from, path)) = member_path(source, position) {
+        let mut parts = path.split('.');
+        let Some(root) = parts.next() else {
+            return Ok(None);
+        };
+        let mut fields;
+        let detail;
+        if let Some(specifier) = imports.get(root) {
+            let mut loader = environment.create_loader();
+            let loaded = loader.load(Some(key), specifier)?;
+            detail = match &loaded {
+                LoadedImport::Source(source) => source.name.clone(),
+                LoadedImport::Value(value) => value.key.clone(),
+            };
+            fields = match loaded {
+                LoadedImport::Source(source) => collect_fields(&tokenize(&source.source)),
+                LoadedImport::Value(value) => fields_from_host_value(&value.value),
+            };
+        } else if let Some(local) = local_fields.get(root) {
+            fields = local.clone();
+            detail = String::from("local value");
+        } else if let Some(global) = globals.get(root) {
+            fields = global.clone();
+            detail = String::from("host global");
+        } else {
+            return Ok(None);
+        }
+
+        for part in parts {
+            let Some(nested) = fields.remove(part) else {
+                return Ok(None);
+            };
+            fields = nested;
+        }
+        let items = fields
+            .into_iter()
+            .map(|(label, children)| CompletionItem {
+                label,
+                kind: if children.is_empty() {
+                    CompletionKind::Property
+                } else {
+                    CompletionKind::Namespace
+                },
+                detail: Some(detail.clone()),
+                priority: 30,
+            })
+            .collect();
+        return Ok(Some(CompletionResult {
+            from,
+            items: unique_items(items),
+        }));
+    }
+
+    let word_from = word_start(source, position);
+    if word_from == position && !explicit {
+        return Ok(None);
+    }
+
+    let mut items = builtin_items();
+    for (label, children) in local_fields {
+        items.push(CompletionItem {
+            label,
+            kind: if children.is_empty() {
+                CompletionKind::Variable
+            } else {
+                CompletionKind::Namespace
+            },
+            detail: Some(if children.is_empty() {
+                String::from("local value")
+            } else {
+                String::from("local object")
+            }),
+            priority: 20,
+        });
+    }
+    for label in collect_parameters(&tokens) {
+        items.push(CompletionItem {
+            label,
+            kind: CompletionKind::Variable,
+            detail: Some(String::from("parameter")),
+            priority: 20,
+        });
+    }
+    for (label, specifier) in imports {
+        items.push(CompletionItem {
+            label,
+            kind: CompletionKind::Namespace,
+            detail: Some(specifier),
+            priority: 30,
+        });
+    }
+    for (label, children) in globals {
+        items.push(CompletionItem {
+            label,
+            kind: if children.is_empty() {
+                CompletionKind::Variable
+            } else {
+                CompletionKind::Namespace
+            },
+            detail: Some(String::from("host global")),
+            priority: 40,
+        });
+    }
+
+    Ok(Some(CompletionResult {
+        from: word_from,
+        items: unique_items(items),
+    }))
+}
+
+fn builtin_items() -> Vec<CompletionItem> {
+    [
+        ("let", CompletionKind::Keyword, "local bindings", 5),
+        ("in", CompletionKind::Keyword, "let body", 0),
+        ("match", CompletionKind::Keyword, "pattern matching", 5),
+        ("import", CompletionKind::Keyword, "load a module", 5),
+        ("default", CompletionKind::Keyword, "fallback value", 0),
+        ("true", CompletionKind::Constant, "Bool", 0),
+        ("false", CompletionKind::Constant, "Bool", 0),
+        ("String", CompletionKind::Type, "string constraint", 5),
+        ("Int", CompletionKind::Type, "integer constraint", 5),
+        ("Float", CompletionKind::Type, "float constraint", 5),
+        ("Bool", CompletionKind::Type, "boolean constraint", 5),
+    ]
+    .into_iter()
+    .map(|(label, kind, detail, priority)| CompletionItem {
+        label: label.into(),
+        kind,
+        detail: Some(detail.into()),
+        priority,
+    })
+    .collect()
+}
+
+fn collect_globals<E: HostEnvironment>(environment: &E) -> Result<FieldTree> {
+    let mut engine = environment.create_engine()?;
+    let mut fields = FieldTree::new();
+    for (name, value) in engine.global_values()? {
+        fields.insert(name, fields_from_runtime(&mut engine, &value, 0)?);
+    }
+    Ok(fields)
+}
+
+fn fields_from_runtime<L: ImportLoader>(
+    engine: &mut Engine<L>,
+    value: &RuntimeValue,
+    depth: usize,
+) -> Result<FieldTree> {
+    if depth >= 32 {
+        return Ok(FieldTree::new());
+    }
+    let Some(fields) = engine.value_fields(value)? else {
+        return Ok(FieldTree::new());
+    };
+    let mut tree = FieldTree::new();
+    for (name, value) in fields {
+        tree.insert(name, fields_from_runtime(engine, &value, depth + 1)?);
+    }
+    Ok(tree)
+}
+
+fn fields_from_host_value(value: &HostValue) -> FieldTree {
+    match value {
+        HostValue::Object(fields) => fields
+            .iter()
+            .map(|field| (field.name.clone(), fields_from_host_value(&field.value)))
+            .collect(),
+        HostValue::ArrayConstraint {
+            default: Some(value),
+            ..
+        }
+        | HostValue::Abstract {
+            default: Some(value),
+            ..
+        } => fields_from_host_value(value),
+        _ => FieldTree::new(),
+    }
+}
+
+fn unique_items(items: Vec<CompletionItem>) -> Vec<CompletionItem> {
+    let mut unique = HashMap::<String, CompletionItem>::new();
+    let mut order = Vec::new();
+    for item in items {
+        if !unique.contains_key(&item.label) {
+            order.push(item.label.clone());
+        }
+        let replace = unique
+            .get(&item.label)
+            .is_none_or(|previous| item.priority > previous.priority);
+        if replace {
+            unique.insert(item.label.clone(), item);
+        }
+    }
+    order
+        .into_iter()
+        .filter_map(|label| unique.remove(&label))
+        .collect()
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+enum TokenKind {
+    Identifier(String),
+    String(String),
+    Symbol(char),
+    Arrow,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+struct Token {
+    kind: TokenKind,
+}
+
+fn tokenize(source: &str) -> Vec<Token> {
+    let bytes = source.as_bytes();
+    let mut tokens = Vec::new();
+    let mut index = 0;
+    while index < bytes.len() {
+        match bytes[index] {
+            b' ' | b'\t' | b'\r' | b'\n' => index += 1,
+            b'#' => {
+                while index < bytes.len() && bytes[index] != b'\n' {
+                    index += 1;
+                }
+            }
+            b'"' => {
+                index += 1;
+                let start = index;
+                let mut escaped = false;
+                while index < bytes.len() {
+                    let byte = bytes[index];
+                    if escaped {
+                        escaped = false;
+                    } else if byte == b'\\' {
+                        escaped = true;
+                    } else if byte == b'"' || byte == b'\n' {
+                        break;
+                    }
+                    index += 1;
+                }
+                let value = unescape_string(&source[start..index]);
+                index = index.saturating_add(1);
+                tokens.push(Token {
+                    kind: TokenKind::String(value),
+                });
+            }
+            byte if is_identifier_start(byte) => {
+                let start = index;
+                index += 1;
+                while index < bytes.len() && is_identifier_continue(bytes[index]) {
+                    index += 1;
+                }
+                tokens.push(Token {
+                    kind: TokenKind::Identifier(source[start..index].into()),
+                });
+            }
+            b'=' if bytes.get(index + 1) == Some(&b'>') => {
+                tokens.push(Token {
+                    kind: TokenKind::Arrow,
+                });
+                index += 2;
+            }
+            byte => {
+                tokens.push(Token {
+                    kind: TokenKind::Symbol(byte as char),
+                });
+                index += 1;
+            }
+        }
+    }
+    tokens
+}
+
+fn unescape_string(value: &str) -> String {
+    let mut chars = value.chars();
+    let mut unescaped = String::new();
+    while let Some(ch) = chars.next() {
+        if ch != '\\' {
+            unescaped.push(ch);
+            continue;
+        }
+        let Some(escaped) = chars.next() else {
+            unescaped.push('\\');
+            break;
+        };
+        unescaped.push(match escaped {
+            'n' => '\n',
+            'r' => '\r',
+            't' => '\t',
+            escaped => escaped,
+        });
+    }
+    unescaped
+}
+
+fn collect_fields(tokens: &[Token]) -> FieldTree {
+    let mut fields = FieldTree::new();
+    collect_fields_in(tokens, 0, tokens.len(), &mut fields);
+    fields
+}
+
+fn collect_fields_in(tokens: &[Token], start: usize, end: usize, fields: &mut FieldTree) {
+    let mut index = start;
+    while index < end {
+        let Some((path, equals)) = field_definition_at(tokens, index, end) else {
+            index += 1;
+            continue;
+        };
+        let value_start = equals + 1;
+        let value_end = definition_end(tokens, value_start, end);
+        let mut nested = &mut *fields;
+        for part in path {
+            nested = nested.0.entry(part).or_default();
+        }
+        collect_fields_in(tokens, value_start, value_end, nested);
+        index = value_end.saturating_add(1);
+    }
+}
+
+fn field_definition_at(tokens: &[Token], start: usize, end: usize) -> Option<(Vec<String>, usize)> {
+    let TokenKind::Identifier(first) = &tokens.get(start)?.kind else {
+        return None;
+    };
+    let mut path = vec![first.clone()];
+    let mut index = start + 1;
+    while index + 1 < end
+        && matches!(tokens[index].kind, TokenKind::Symbol('.'))
+        && matches!(tokens[index + 1].kind, TokenKind::Identifier(_))
+    {
+        let TokenKind::Identifier(part) = &tokens[index + 1].kind else {
+            unreachable!()
+        };
+        path.push(part.clone());
+        index += 2;
+    }
+    matches!(
+        tokens.get(index).map(|token| &token.kind),
+        Some(TokenKind::Symbol('='))
+    )
+    .then_some((path, index))
+}
+
+fn definition_end(tokens: &[Token], start: usize, end: usize) -> usize {
+    let mut delimiters = Vec::new();
+    for (index, token) in tokens.iter().enumerate().take(end).skip(start) {
+        match token.kind {
+            TokenKind::Symbol('(' | '[' | '{') => delimiters.push(token.kind.clone()),
+            TokenKind::Symbol(')') if matches!(delimiters.last(), Some(TokenKind::Symbol('('))) => {
+                delimiters.pop();
+            }
+            TokenKind::Symbol(']') if matches!(delimiters.last(), Some(TokenKind::Symbol('['))) => {
+                delimiters.pop();
+            }
+            TokenKind::Symbol('}') if matches!(delimiters.last(), Some(TokenKind::Symbol('{'))) => {
+                delimiters.pop();
+            }
+            TokenKind::Symbol(';') if delimiters.is_empty() => return index,
+            _ => {}
+        }
+    }
+    end
+}
+
+fn collect_import_bindings(tokens: &[Token]) -> BTreeMap<String, String> {
+    let mut imports = BTreeMap::new();
+    for window in tokens.windows(4) {
+        let (
+            TokenKind::Identifier(binding),
+            TokenKind::Symbol('='),
+            TokenKind::Identifier(keyword),
+            TokenKind::String(specifier),
+        ) = (
+            &window[0].kind,
+            &window[1].kind,
+            &window[2].kind,
+            &window[3].kind,
+        )
+        else {
+            continue;
+        };
+        if keyword == "import" {
+            imports.insert(binding.clone(), specifier.clone());
+        }
+    }
+    imports
+}
+
+fn collect_parameters(tokens: &[Token]) -> Vec<String> {
+    let mut parameters = Vec::new();
+    for (close, token) in tokens.iter().enumerate() {
+        if !matches!(token.kind, TokenKind::Symbol(')'))
+            || !matches!(
+                tokens.get(close + 1).map(|token| &token.kind),
+                Some(TokenKind::Arrow)
+            )
+        {
+            continue;
+        }
+        let Some(open) = matching_open_paren(tokens, close) else {
+            continue;
+        };
+        let mut depth = 0usize;
+        let mut segment_start = true;
+        for token in &tokens[open + 1..close] {
+            match &token.kind {
+                TokenKind::Symbol('(' | '[' | '{') => depth += 1,
+                TokenKind::Symbol(')' | ']' | '}') => depth = depth.saturating_sub(1),
+                TokenKind::Symbol(',') if depth == 0 => segment_start = true,
+                TokenKind::Identifier(name) if depth == 0 && segment_start => {
+                    parameters.push(name.clone());
+                    segment_start = false;
+                }
+                _ => {}
+            }
+        }
+    }
+    parameters
+}
+
+fn matching_open_paren(tokens: &[Token], close: usize) -> Option<usize> {
+    let mut depth = 0usize;
+    for index in (0..close).rev() {
+        match tokens[index].kind {
+            TokenKind::Symbol(')') => depth += 1,
+            TokenKind::Symbol('(') if depth == 0 => return Some(index),
+            TokenKind::Symbol('(') => depth -= 1,
+            _ => {}
+        }
+    }
+    None
+}
+
+fn unfinished_import(source: &str, position: usize) -> Option<(usize, &str)> {
+    let bytes = source.as_bytes();
+    let mut index = 0usize;
+    let mut previous_word = None;
+    while index < position {
+        match bytes[index] {
+            b' ' | b'\t' | b'\r' | b'\n' => index += 1,
+            b'#' => {
+                while index < position && bytes[index] != b'\n' {
+                    index += 1;
+                }
+                previous_word = None;
+            }
+            b'"' => {
+                let from = index + 1;
+                index += 1;
+                let mut escaped = false;
+                while index < position {
+                    let byte = bytes[index];
+                    if escaped {
+                        escaped = false;
+                    } else if byte == b'\\' {
+                        escaped = true;
+                    } else if byte == b'"' || byte == b'\n' {
+                        break;
+                    }
+                    index += 1;
+                }
+                if index == position && previous_word == Some("import") {
+                    return Some((from, &source[from..position]));
+                }
+                index = index.saturating_add(1);
+                previous_word = None;
+            }
+            byte if is_identifier_start(byte) => {
+                let start = index;
+                index += 1;
+                while index < position && is_identifier_continue(bytes[index]) {
+                    index += 1;
+                }
+                previous_word = Some(&source[start..index]);
+            }
+            _ => {
+                index += 1;
+                previous_word = None;
+            }
+        }
+    }
+    None
+}
+
+fn in_string_or_comment(source: &str, position: usize) -> bool {
+    let bytes = source.as_bytes();
+    let mut index = 0usize;
+    while index < position {
+        match bytes[index] {
+            b'#' => {
+                while index < position && bytes[index] != b'\n' {
+                    index += 1;
+                }
+                if index == position {
+                    return true;
+                }
+            }
+            b'"' => {
+                index += 1;
+                let mut escaped = false;
+                while index < position {
+                    let byte = bytes[index];
+                    if escaped {
+                        escaped = false;
+                    } else if byte == b'\\' {
+                        escaped = true;
+                    } else if byte == b'"' || byte == b'\n' {
+                        break;
+                    }
+                    index += 1;
+                }
+                if index == position {
+                    return true;
+                }
+                index = index.saturating_add(1);
+            }
+            _ => index += 1,
+        }
+    }
+    false
+}
+
+fn member_path(source: &str, position: usize) -> Option<(usize, &str)> {
+    let bytes = source.as_bytes();
+    let from = word_start(source, position);
+    if from == 0 || bytes[from - 1] != b'.' {
+        return None;
+    }
+    let mut base_start = from - 1;
+    while base_start > 0 {
+        let byte = bytes[base_start - 1];
+        if is_identifier_continue(byte) || byte == b'.' {
+            base_start -= 1;
+        } else {
+            break;
+        }
+    }
+    let base = &source[base_start..from - 1];
+    (!base.is_empty()
+        && base
+            .split('.')
+            .all(|part| !part.is_empty() && is_identifier(part)))
+    .then_some((from, base))
+}
+
+fn word_start(source: &str, position: usize) -> usize {
+    let bytes = source.as_bytes();
+    let mut from = position;
+    while from > 0 && is_identifier_continue(bytes[from - 1]) {
+        from -= 1;
+    }
+    from
+}
+
+fn is_identifier(value: &str) -> bool {
+    let bytes = value.as_bytes();
+    bytes.first().is_some_and(|byte| is_identifier_start(*byte))
+        && bytes[1..].iter().all(|byte| is_identifier_continue(*byte))
+}
+
+fn is_identifier_start(byte: u8) -> bool {
+    byte.is_ascii_alphabetic() || byte == b'_'
+}
+
+fn is_identifier_continue(byte: u8) -> bool {
+    is_identifier_start(byte) || byte.is_ascii_digit()
+}
+
+fn floor_char_boundary(source: &str, mut position: usize) -> usize {
+    while !source.is_char_boundary(position) {
+        position -= 1;
+    }
+    position
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::BTreeMap;
+
+    use decodal::{
+        Diagnostic, DiagnosticKind, EmptyLoader, HostValue, ImportCandidate, LoadedImport, Span,
+    };
+
+    use super::*;
+
+    #[derive(Clone, Default)]
+    struct TestEnvironment {
+        files: BTreeMap<String, String>,
+    }
+
+    #[derive(Clone, Default)]
+    struct TestLoader {
+        files: BTreeMap<String, String>,
+    }
+
+    impl ImportLoader for TestLoader {
+        fn load(&mut self, _current_key: Option<&str>, specifier: &str) -> Result<LoadedImport> {
+            if specifier == "./post.md" {
+                return Ok(LoadedImport::value(
+                    "post.md",
+                    HostValue::object([
+                        (
+                            "frontmatter",
+                            HostValue::object([
+                                ("title", HostValue::string("Hello")),
+                                ("draft", HostValue::bool(false)),
+                            ]),
+                        ),
+                        ("body", HostValue::string("# Hello")),
+                    ]),
+                ));
+            }
+            let key = resolve_virtual("main.dcdl", specifier);
+            let Some(source) = self.files.get(&key) else {
+                return Err(Diagnostic::new(
+                    DiagnosticKind::Import,
+                    Span::default(),
+                    "unknown import",
+                ));
+            };
+            Ok(LoadedImport::source(key.clone(), key, source))
+        }
+
+        fn complete_import(
+            &mut self,
+            _current_key: Option<&str>,
+            prefix: &str,
+        ) -> Result<Vec<ImportCandidate>> {
+            Ok(self
+                .files
+                .keys()
+                .map(|path| format!("./{path}"))
+                .filter(|path| path.starts_with(prefix))
+                .map(ImportCandidate::new)
+                .collect())
+        }
+    }
+
+    impl HostEnvironment for TestEnvironment {
+        type Loader = TestLoader;
+
+        fn create_loader(&self) -> Self::Loader {
+            TestLoader {
+                files: self.files.clone(),
+            }
+        }
+
+        fn configure_engine(&self, engine: &mut Engine<Self::Loader>) -> Result<()> {
+            engine.bind_global(
+                "App",
+                HostValue::object([(
+                    "config",
+                    HostValue::object([
+                        ("enabled", HostValue::bool_type()),
+                        ("port", HostValue::int_type()),
+                    ]),
+                )]),
+            )?;
+            Ok(())
+        }
+    }
+
+    fn environment() -> TestEnvironment {
+        TestEnvironment {
+            files: BTreeMap::from([
+                (
+                    "schemas/service.dcdl".into(),
+                    "Service = { name = String; resources = { cpu = Int; }; };".into(),
+                ),
+                (
+                    "env/production.dcdl".into(),
+                    "capacity = { cpu = 2000; };".into(),
+                ),
+                (
+                    "資料/service.dcdl".into(),
+                    "Service = { label = String; };".into(),
+                ),
+            ]),
+        }
+    }
+
+    fn labels(result: CompletionResult) -> Vec<String> {
+        result.items.into_iter().map(|item| item.label).collect()
+    }
+
+    #[test]
+    fn completes_import_paths_from_the_host_loader() {
+        let source = "schema = import \"./sch";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(result.from, source.len() - 5);
+        assert!(labels(result).contains(&"./schemas/service.dcdl".into()));
+    }
+
+    #[test]
+    fn completes_nested_fields_from_imported_source() {
+        let source = "let schema = import \"./schemas/service.dcdl\"; in schema.Service.";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(labels(result), ["name", "resources"]);
+    }
+
+    #[test]
+    fn completes_structured_host_imports() {
+        let source = "let post = import \"./post.md\"; in post.frontmatter.";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(labels(result), ["draft", "title"]);
+    }
+
+    #[test]
+    fn preserves_unicode_import_specifiers() {
+        let source = "let schema = import \"./資料/service.dcdl\"; in schema.Service.";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(labels(result), ["label"]);
+    }
+
+    #[test]
+    fn completes_host_globals_from_the_evaluation_environment() {
+        let source = "App.config.";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(labels(result), ["enabled", "port"]);
+    }
+
+    #[test]
+    fn completes_language_locals_parameters_and_partial_members() {
+        let source = "let service = { port = 8080; }; in (value: Int) => service.po";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        assert_eq!(result.from, source.len() - 2);
+        assert_eq!(labels(result), ["port"]);
+
+        let source = "let service = { port = 8080; }; in (value: Int) => val";
+        let result = complete(&environment(), "main.dcdl", source, source.len(), false)
+            .unwrap()
+            .unwrap();
+        let labels = labels(result);
+        assert!(labels.contains(&"String".into()));
+        assert!(labels.contains(&"service".into()));
+        assert!(labels.contains(&"value".into()));
+        assert!(labels.contains(&"App".into()));
+    }
+
+    #[test]
+    fn suppresses_completions_in_strings_and_comments() {
+        let string = "value = \"hello world\"";
+        assert!(
+            complete(&environment(), "main.dcdl", string, string.len() - 1, false)
+                .unwrap()
+                .is_none()
+        );
+        let comment = "value = true; # hello";
+        assert!(
+            complete(&environment(), "main.dcdl", comment, comment.len(), false)
+                .unwrap()
+                .is_none()
+        );
+    }
+
+    #[test]
+    fn empty_environment_remains_supported() {
+        let result = complete(&EmptyEnvironment, "main.dcdl", "Str", 3, false)
+            .unwrap()
+            .unwrap();
+        assert!(labels(result).contains(&"String".into()));
+    }
+
+    struct EmptyEnvironment;
+
+    impl HostEnvironment for EmptyEnvironment {
+        type Loader = EmptyLoader;
+
+        fn create_loader(&self) -> Self::Loader {
+            EmptyLoader
+        }
+    }
+
+    fn resolve_virtual(current: &str, specifier: &str) -> String {
+        let mut parts = current.split('/').collect::<Vec<_>>();
+        parts.pop();
+        for part in specifier.split('/') {
+            match part {
+                "" | "." => {}
+                ".." => {
+                    parts.pop();
+                }
+                part => parts.push(part),
+            }
+        }
+        parts.join("/")
+    }
+}
@@ -0,0 +1,204 @@
+use decodal::{Data, Diagnostic, HostEnvironment, Result};
+
+mod completion;
+
+pub use completion::{CompletionItem, CompletionKind, CompletionResult};
+
+/// Semantic tooling backed by the same host environment as production.
+pub struct LanguageService<E> {
+    environment: E,
+}
+
+impl<E> LanguageService<E> {
+    pub fn new(environment: E) -> Self {
+        Self { environment }
+    }
+
+    pub fn environment(&self) -> &E {
+        &self.environment
+    }
+
+    pub fn environment_mut(&mut self) -> &mut E {
+        &mut self.environment
+    }
+
+    pub fn into_environment(self) -> E {
+        self.environment
+    }
+}
+
+impl<E: HostEnvironment> LanguageService<E> {
+    /// Runs the production parse, evaluation, and materialization pipeline.
+    pub fn evaluate(
+        &self,
+        key: impl Into<String>,
+        name: impl Into<String>,
+        source: &str,
+    ) -> Result<Data> {
+        let mut engine = self.environment.create_engine()?;
+        let module = engine.add_root_source(key, name, source)?;
+        let value = engine.eval_module(module)?;
+        engine.materialize(&value)
+    }
+
+    /// Evaluates a document and exposes failures in an editor-friendly form.
+    ///
+    /// The evaluator currently stops at the first failure, so an invalid
+    /// analysis contains one diagnostic. The collection leaves room for a
+    /// future diagnostic-accumulation pass without changing this API.
+    pub fn analyze(
+        &self,
+        key: impl Into<String>,
+        name: impl Into<String>,
+        source: &str,
+    ) -> SemanticAnalysis {
+        match self.evaluate(key, name, source) {
+            Ok(data) => SemanticAnalysis {
+                data: Some(data),
+                diagnostics: Vec::new(),
+            },
+            Err(diagnostic) => SemanticAnalysis {
+                data: None,
+                diagnostics: vec![diagnostic],
+            },
+        }
+    }
+
+    /// Completes the document using the same host globals and import loader as
+    /// production evaluation.
+    pub fn complete(
+        &self,
+        key: impl AsRef<str>,
+        source: &str,
+        position: usize,
+        explicit: bool,
+    ) -> Result<Option<CompletionResult>> {
+        completion::complete(&self.environment, key.as_ref(), source, position, explicit)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct SemanticAnalysis {
+    pub data: Option<Data>,
+    pub diagnostics: Vec<Diagnostic>,
+}
+
+impl SemanticAnalysis {
+    pub fn is_valid(&self) -> bool {
+        self.diagnostics.is_empty()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use decodal::{
+        Data, Diagnostic, DiagnosticKind, Engine, HostValue, ImportLoader, LoadedImport, Span,
+    };
+
+    use super::*;
+
+    const ROOT: &str = r#"Post & import "./post.md""#;
+
+    struct ContentEnvironment {
+        draft: HostValue,
+    }
+
+    struct ContentLoader {
+        draft: HostValue,
+    }
+
+    impl ImportLoader for ContentLoader {
+        fn load(
+            &mut self,
+            _current_key: Option<&str>,
+            specifier: &str,
+        ) -> decodal::Result<LoadedImport> {
+            if specifier != "./post.md" {
+                return Err(Diagnostic::new(
+                    DiagnosticKind::Import,
+                    Span::default(),
+                    "unknown content import",
+                ));
+            }
+            Ok(LoadedImport::value(
+                "content/post.md",
+                HostValue::object([
+                    (
+                        "frontmatter",
+                        HostValue::object([
+                            ("title", HostValue::string("Hello")),
+                            ("draft", self.draft.clone()),
+                        ]),
+                    ),
+                    ("body", HostValue::string("# Hello")),
+                ]),
+            ))
+        }
+    }
+
+    impl HostEnvironment for ContentEnvironment {
+        type Loader = ContentLoader;
+
+        fn create_loader(&self) -> Self::Loader {
+            ContentLoader {
+                draft: self.draft.clone(),
+            }
+        }
+
+        fn configure_engine(&self, engine: &mut Engine<Self::Loader>) -> decodal::Result<()> {
+            engine.bind_global(
+                "Post",
+                HostValue::object([
+                    (
+                        "frontmatter",
+                        HostValue::object([
+                            ("title", HostValue::string_type()),
+                            ("draft", HostValue::bool_type()),
+                        ]),
+                    ),
+                    ("body", HostValue::string_type()),
+                ]),
+            )?;
+            Ok(())
+        }
+    }
+
+    fn evaluate_direct(environment: &ContentEnvironment) -> decodal::Result<Data> {
+        let mut engine = environment.create_engine()?;
+        let module = engine.add_root_source("main.dcdl", "main.dcdl", ROOT)?;
+        let value = engine.eval_module(module)?;
+        engine.materialize(&value)
+    }
+
+    #[test]
+    fn injected_environment_matches_direct_evaluation() {
+        let environment = ContentEnvironment {
+            draft: HostValue::bool(false),
+        };
+        let direct = evaluate_direct(&environment).unwrap();
+        let service = LanguageService::new(&environment);
+        let analysis = service.analyze("main.dcdl", "main.dcdl", ROOT);
+
+        assert!(analysis.is_valid());
+        assert_eq!(analysis.data, Some(direct));
+    }
+
+    #[test]
+    fn injected_environment_preserves_import_diagnostics() {
+        let service = LanguageService::new(ContentEnvironment {
+            draft: HostValue::string("maybe"),
+        });
+        let analysis = service.analyze("main.dcdl", "main.dcdl", ROOT);
+
+        assert!(!analysis.is_valid());
+        assert_eq!(analysis.data, None);
+        assert_eq!(
+            analysis.diagnostics[0].message,
+            "expected Bool, found String"
+        );
+        assert_eq!(
+            analysis.diagnostics[0].notes,
+            ["imported `content/post.md` at `frontmatter.draft` supplied a value of type String"]
+        );
+    }
+}
@@ -0,0 +1,22 @@
+[package]
+name = "decodal-language-tools"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Source-level language tooling for Decodal."
+keywords = ["decodal", "formatter", "lsp", "language-tools"]
+categories = ["development-tools", "text-processing"]
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+decodal = { version = "0.2.0", path = "../decodal-core" }
+serde_json.workspace = true
+wasm-bindgen.workspace = true
+
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = false
@@ -0,0 +1,759 @@
+use std::{error::Error, fmt};
+
+use decodal::{
+    Ast, BinaryOp, CompareOp, Expr, ExprId, Field, Param, SourceForm, Span, SyntaxToken,
+    SyntaxTokenKind,
+    ast::{MatchArm, UnaryOp},
+    parse_source, tokenize_source,
+};
+use wasm_bindgen::prelude::*;
+
+const INDENT: usize = 4;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FormatError {
+    message: String,
+}
+
+impl FormatError {
+    fn new(message: impl Into<String>) -> Self {
+        Self {
+            message: message.into(),
+        }
+    }
+
+    pub fn message(&self) -> &str {
+        &self.message
+    }
+}
+
+impl fmt::Display for FormatError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.message)
+    }
+}
+
+impl Error for FormatError {}
+
+/// Formats a complete Decodal source with the canonical parser and syntax tokens.
+///
+/// Native and WebAssembly callers execute this exact implementation. Comments
+/// are recovered from the lossless token stream while expression structure and
+/// precedence come from the same AST used by evaluation.
+pub fn format_source(source: &str) -> Result<String, FormatError> {
+    let parsed = parse_source(source)
+        .map_err(|diagnostic| FormatError::new(format!("parse error: {}", diagnostic.message)))?;
+    let tokens = tokenize_source(source)
+        .map_err(|diagnostic| FormatError::new(format!("lex error: {}", diagnostic.message)))?;
+    Ok(Formatter::new(source, &parsed.ast, tokens).format(parsed.root, parsed.source_form))
+}
+
+#[wasm_bindgen(js_name = formatSource)]
+pub fn format_source_json(source: &str) -> String {
+    match format_source(source) {
+        Ok(formatted) => serde_json::json!({ "ok": true, "source": formatted }).to_string(),
+        Err(error) => serde_json::json!({ "ok": false, "error": error.message() }).to_string(),
+    }
+}
+
+struct Formatter<'a> {
+    source: &'a str,
+    ast: &'a Ast,
+    tokens: Vec<SyntaxToken>,
+    comments: Vec<Span>,
+}
+
+impl<'a> Formatter<'a> {
+    fn new(source: &'a str, ast: &'a Ast, tokens: Vec<SyntaxToken>) -> Self {
+        let comments = tokens
+            .iter()
+            .filter(|token| token.kind == SyntaxTokenKind::Comment)
+            .map(|token| token.span)
+            .collect();
+        Self {
+            source,
+            ast,
+            tokens,
+            comments,
+        }
+    }
+
+    fn format(&self, root: ExprId, source_form: SourceForm) -> String {
+        let mut out = String::new();
+        if source_form == SourceForm::Fields {
+            let Expr::Object(fields) = &self.ast.get(root).expr else {
+                unreachable!("field-form sources parse to an object")
+            };
+            self.write_field_list(&mut out, fields, 0, self.source.len(), 0);
+        } else {
+            let span = self.ast.span(root);
+            self.write_between(&mut out, 0, span.start as usize, None, 0);
+            self.write_expr(&mut out, root, 0, 0);
+            self.write_between(
+                &mut out,
+                span.end as usize,
+                self.source.len(),
+                Some(span.end as usize),
+                0,
+            );
+        }
+        trim_trailing_whitespace(&mut out);
+        out.push('\n');
+        out
+    }
+
+    fn write_field_list(
+        &self,
+        out: &mut String,
+        fields: &[Field],
+        start: usize,
+        end: usize,
+        indent: usize,
+    ) {
+        let mut cursor = start;
+        let mut previous_end = None;
+        for field in fields {
+            let field_start = field.span.start as usize;
+            self.write_between(out, cursor, field_start, previous_end, indent);
+            write_indent(out, indent);
+            self.write_field(out, field, indent);
+            out.push(';');
+            cursor = field.span.end as usize;
+            previous_end = Some(cursor);
+        }
+        self.write_between(out, cursor, end, previous_end, indent);
+    }
+
+    fn write_field(&self, out: &mut String, field: &Field, indent: usize) {
+        let value_start = self.ast.span(field.value).start as usize;
+        if self.has_comment_between(field.span.start as usize, value_start) {
+            out.push_str(self.raw(field.span));
+            return;
+        }
+        for (index, part) in field.path.iter().enumerate() {
+            if index > 0 {
+                out.push('.');
+            }
+            out.push_str(part);
+        }
+        out.push_str(" = ");
+        self.write_expr(out, field.value, indent, 0);
+    }
+
+    fn write_expr(&self, out: &mut String, id: ExprId, indent: usize, parent_prec: u8) {
+        let node = self.ast.get(id);
+        if self.has_comment(node.span)
+            && !matches!(
+                node.expr,
+                Expr::Object(_) | Expr::Array(_) | Expr::Let { .. } | Expr::Match { .. }
+            )
+        {
+            out.push_str(self.raw(node.span));
+            return;
+        }
+
+        let precedence = self.precedence(id);
+        let parenthesize = precedence < parent_prec;
+        if parenthesize {
+            out.push('(');
+        }
+
+        match &node.expr {
+            Expr::Literal(_) | Expr::Ident(_) | Expr::RegexConstraint(_) | Expr::Wildcard => {
+                out.push_str(self.raw(node.span));
+            }
+            Expr::Object(fields) => self.write_object(out, node.span, fields, indent),
+            Expr::Array(items) => self.write_array(out, node.span, items, indent),
+            Expr::ArrayConstraint { item } => {
+                out.push_str("[...");
+                self.write_expr(out, *item, indent, 0);
+                out.push(']');
+            }
+            Expr::Let { bindings, body } => self.write_let(out, node.span, bindings, *body, indent),
+            Expr::Import(_) => {
+                out.push_str("import ");
+                let raw = self.raw(node.span);
+                out.push_str(raw.strip_prefix("import").unwrap_or(raw).trim());
+            }
+            Expr::Path { base, field } => {
+                self.write_expr(out, *base, indent, precedence);
+                out.push('.');
+                out.push_str(field);
+            }
+            Expr::Call { callee, args } => {
+                self.write_expr(out, *callee, indent, precedence);
+                out.push('(');
+                for (index, argument) in args.iter().enumerate() {
+                    if index > 0 {
+                        out.push_str(", ");
+                    }
+                    self.write_expr(out, *argument, indent, 0);
+                }
+                out.push(')');
+            }
+            Expr::Function { params, body } => self.write_function(out, params, *body, indent),
+            Expr::Parenthesized { expr } => {
+                out.push('(');
+                self.write_expr(out, *expr, indent, 0);
+                out.push(')');
+            }
+            Expr::Match { scrutinee, arms } => {
+                self.write_match(out, node.span, *scrutinee, arms, indent)
+            }
+            Expr::Unary { op, expr } => {
+                out.push_str(match op {
+                    UnaryOp::Neg => "-",
+                    UnaryOp::Not => "!",
+                });
+                self.write_expr(out, *expr, indent, precedence);
+            }
+            Expr::Binary { op, lhs, rhs } => {
+                self.write_expr(out, *lhs, indent, precedence);
+                out.push(' ');
+                out.push_str(binary_operator(*op));
+                out.push(' ');
+                self.write_expr(out, *rhs, indent, precedence + 1);
+            }
+            Expr::Default { base, fallback } => {
+                self.write_expr(out, *base, indent, precedence);
+                out.push_str(" default ");
+                self.write_expr(out, *fallback, indent, precedence + 1);
+            }
+            Expr::CompareConstraint { op, value } => {
+                out.push_str(compare_operator(*op));
+                out.push(' ');
+                self.write_expr(out, *value, indent, precedence);
+            }
+        }
+
+        if parenthesize {
+            out.push(')');
+        }
+    }
+
+    fn write_object(&self, out: &mut String, span: Span, fields: &[Field], indent: usize) {
+        let (start, end) =
+            self.delimited_range(span, SyntaxTokenKind::LBrace, SyntaxTokenKind::RBrace);
+        if fields.is_empty() && !self.has_comment_between(start, end) {
+            out.push_str("{}");
+            return;
+        }
+        out.push_str("{\n");
+        self.write_field_list(out, fields, start, end, indent + INDENT);
+        write_indent(out, indent);
+        out.push('}');
+    }
+
+    fn write_array(&self, out: &mut String, span: Span, items: &[ExprId], indent: usize) {
+        let (start, end) =
+            self.delimited_range(span, SyntaxTokenKind::LBracket, SyntaxTokenKind::RBracket);
+        if items.is_empty() && !self.has_comment_between(start, end) {
+            out.push_str("[]");
+            return;
+        }
+        let inline = !self.has_comment_between(start, end)
+            && items.iter().all(|item| self.is_inline_expr(*item));
+        if inline {
+            out.push('[');
+            for (index, item) in items.iter().enumerate() {
+                if index > 0 {
+                    out.push_str(", ");
+                }
+                self.write_expr(out, *item, indent, 0);
+            }
+            out.push(']');
+            return;
+        }
+
+        out.push_str("[\n");
+        let mut cursor = start;
+        let mut previous_end = None;
+        for item in items {
+            let item_span = self.ast.span(*item);
+            self.write_between(
+                out,
+                cursor,
+                item_span.start as usize,
+                previous_end,
+                indent + INDENT,
+            );
+            write_indent(out, indent + INDENT);
+            self.write_expr(out, *item, indent + INDENT, 0);
+            out.push(',');
+            cursor = item_span.end as usize;
+            previous_end = Some(cursor);
+        }
+        self.write_between(out, cursor, end, previous_end, indent + INDENT);
+        write_indent(out, indent);
+        out.push(']');
+    }
+
+    fn write_let(
+        &self,
+        out: &mut String,
+        span: Span,
+        bindings: &[Field],
+        body: ExprId,
+        indent: usize,
+    ) {
+        let body_span = self.ast.span(body);
+        let in_token = self
+            .tokens_between(span.start as usize, body_span.start as usize)
+            .rev()
+            .find(|token| token.kind == SyntaxTokenKind::In)
+            .expect("parsed let expressions contain `in`");
+        let let_token = self
+            .tokens_between(span.start as usize, span.end as usize)
+            .find(|token| token.kind == SyntaxTokenKind::Let)
+            .expect("parsed let expressions contain `let`");
+
+        out.push_str("let\n");
+        self.write_field_list(
+            out,
+            bindings,
+            let_token.span.end as usize,
+            in_token.span.start as usize,
+            indent + INDENT,
+        );
+        write_indent(out, indent);
+        out.push_str("in");
+        self.write_between(
+            out,
+            in_token.span.end as usize,
+            body_span.start as usize,
+            Some(in_token.span.end as usize),
+            indent + INDENT,
+        );
+        write_indent(out, indent + INDENT);
+        self.write_expr(out, body, indent + INDENT, 0);
+    }
+
+    fn write_function(&self, out: &mut String, params: &[Param], body: ExprId, indent: usize) {
+        out.push('(');
+        for (index, parameter) in params.iter().enumerate() {
+            if index > 0 {
+                out.push_str(", ");
+            }
+            out.push_str(&parameter.name);
+            if let Some(constraint) = parameter.constraint {
+                out.push_str(": ");
+                self.write_expr(out, constraint, indent, 0);
+            }
+        }
+        out.push_str(") =>");
+        if self.is_inline_expr(body) {
+            out.push(' ');
+            self.write_expr(out, body, indent, 0);
+        } else {
+            out.push('\n');
+            write_indent(out, indent + INDENT);
+            self.write_expr(out, body, indent + INDENT, 0);
+        }
+    }
+
+    fn write_match(
+        &self,
+        out: &mut String,
+        span: Span,
+        scrutinee: ExprId,
+        arms: &[MatchArm],
+        indent: usize,
+    ) {
+        out.push_str("match ");
+        self.write_expr(out, scrutinee, indent, 0);
+        let scrutinee_end = self.ast.span(scrutinee).end as usize;
+        let open = self
+            .tokens_between(scrutinee_end, span.end as usize)
+            .find(|token| token.kind == SyntaxTokenKind::LBrace)
+            .expect("parsed match expressions contain `{`");
+        let close = self
+            .tokens_between(open.span.end as usize, span.end as usize)
+            .rev()
+            .find(|token| token.kind == SyntaxTokenKind::RBrace)
+            .expect("parsed match expressions contain `}`");
+        let start = open.span.end as usize;
+        let end = close.span.start as usize;
+        if self.has_comment_between(scrutinee_end, open.span.start as usize) {
+            self.write_between(
+                out,
+                scrutinee_end,
+                open.span.start as usize,
+                Some(scrutinee_end),
+                indent,
+            );
+            write_indent(out, indent);
+            out.push('{');
+        } else {
+            out.push_str(" {");
+        }
+        if arms.is_empty() && !self.has_comment_between(start, end) {
+            out.push('}');
+            return;
+        }
+
+        out.push('\n');
+        let mut cursor = start;
+        let mut previous_end = None;
+        for arm in arms {
+            self.write_between(
+                out,
+                cursor,
+                arm.span.start as usize,
+                previous_end,
+                indent + INDENT,
+            );
+            write_indent(out, indent + INDENT);
+            if self.has_comment_between(
+                self.ast.span(arm.pattern).end as usize,
+                self.ast.span(arm.body).start as usize,
+            ) {
+                out.push_str(self.raw(arm.span));
+            } else {
+                self.write_expr(out, arm.pattern, indent + INDENT, 0);
+                out.push_str(": ");
+                self.write_expr(out, arm.body, indent + INDENT, 0);
+            }
+            out.push(';');
+            cursor = arm.span.end as usize;
+            previous_end = Some(cursor);
+        }
+        self.write_between(out, cursor, end, previous_end, indent + INDENT);
+        write_indent(out, indent);
+        out.push('}');
+    }
+
+    fn write_between(
+        &self,
+        out: &mut String,
+        start: usize,
+        end: usize,
+        previous_end: Option<usize>,
+        indent: usize,
+    ) {
+        let mut cursor = start.min(end);
+        for comment in self.comments_between(start, end) {
+            let comment_start = comment.start as usize;
+            let trailing = previous_end.is_some_and(|previous| {
+                !out.ends_with('\n') && self.same_line(previous, comment_start)
+            });
+            if trailing {
+                out.push(' ');
+                out.push_str(self.raw(*comment));
+                out.push('\n');
+            } else {
+                ensure_line_break(out);
+                if self.has_blank_line(cursor, comment_start) {
+                    ensure_blank_line(out);
+                }
+                write_indent(out, indent);
+                out.push_str(self.raw(*comment));
+                out.push('\n');
+            }
+            cursor = comment.end as usize;
+        }
+        if previous_end.is_some() {
+            ensure_line_break(out);
+        }
+        if self.has_blank_line(cursor, end) {
+            ensure_blank_line(out);
+        }
+    }
+
+    fn precedence(&self, id: ExprId) -> u8 {
+        match &self.ast.get(id).expr {
+            Expr::Default { .. } => 1,
+            Expr::Binary { op, .. } => match op {
+                BinaryOp::Patch => 3,
+                BinaryOp::And => 5,
+                BinaryOp::LogicalOr => 7,
+                BinaryOp::LogicalAnd => 9,
+                BinaryOp::Equal
+                | BinaryOp::NotEqual
+                | BinaryOp::Greater
+                | BinaryOp::GreaterEqual
+                | BinaryOp::Less
+                | BinaryOp::LessEqual => 11,
+                BinaryOp::Concat => 12,
+                BinaryOp::Add | BinaryOp::Sub => 13,
+                BinaryOp::Mul | BinaryOp::Div => 15,
+            },
+            Expr::Unary { .. } | Expr::CompareConstraint { .. } => 17,
+            Expr::Call { .. } | Expr::Path { .. } => 19,
+            Expr::Parenthesized { .. } => 20,
+            _ => 20,
+        }
+    }
+
+    fn is_inline_expr(&self, id: ExprId) -> bool {
+        let node = self.ast.get(id);
+        if self.has_comment(node.span) {
+            return false;
+        }
+        match &node.expr {
+            Expr::Literal(_)
+            | Expr::Ident(_)
+            | Expr::RegexConstraint(_)
+            | Expr::Wildcard
+            | Expr::Import(_)
+            | Expr::CompareConstraint { .. } => true,
+            Expr::Path { base, .. } => self.is_inline_expr(*base),
+            Expr::Call { callee, args } => {
+                self.is_inline_expr(*callee)
+                    && args.iter().all(|argument| self.is_inline_expr(*argument))
+            }
+            Expr::Unary { expr, .. } => self.is_inline_expr(*expr),
+            Expr::Binary { lhs, rhs, .. } => self.is_inline_expr(*lhs) && self.is_inline_expr(*rhs),
+            Expr::Default { base, fallback } => {
+                self.is_inline_expr(*base) && self.is_inline_expr(*fallback)
+            }
+            Expr::Array(items) => items.iter().all(|item| self.is_inline_expr(*item)),
+            Expr::ArrayConstraint { item } => self.is_inline_expr(*item),
+            Expr::Parenthesized { expr } => self.is_inline_expr(*expr),
+            Expr::Object(_) | Expr::Let { .. } | Expr::Function { .. } | Expr::Match { .. } => {
+                false
+            }
+        }
+    }
+
+    fn delimited_range(
+        &self,
+        span: Span,
+        open_kind: SyntaxTokenKind,
+        close_kind: SyntaxTokenKind,
+    ) -> (usize, usize) {
+        let open = self
+            .tokens_between(span.start as usize, span.end as usize)
+            .find(|token| same_kind(&token.kind, &open_kind))
+            .expect("parsed delimited expressions contain an opening token");
+        let close = self
+            .tokens_between(open.span.end as usize, span.end as usize)
+            .rev()
+            .find(|token| same_kind(&token.kind, &close_kind))
+            .expect("parsed delimited expressions contain a closing token");
+        (open.span.end as usize, close.span.start as usize)
+    }
+
+    fn tokens_between(
+        &self,
+        start: usize,
+        end: usize,
+    ) -> impl DoubleEndedIterator<Item = &SyntaxToken> {
+        self.tokens.iter().filter(move |token| {
+            token.span.start as usize >= start && token.span.end as usize <= end
+        })
+    }
+
+    fn comments_between(&self, start: usize, end: usize) -> impl Iterator<Item = &Span> {
+        self.comments
+            .iter()
+            .filter(move |comment| comment.start as usize >= start && comment.end as usize <= end)
+    }
+
+    fn has_comment(&self, span: Span) -> bool {
+        self.has_comment_between(span.start as usize, span.end as usize)
+    }
+
+    fn has_comment_between(&self, start: usize, end: usize) -> bool {
+        self.comments_between(start, end).next().is_some()
+    }
+
+    fn same_line(&self, start: usize, end: usize) -> bool {
+        !self.slice(start, end).contains('\n')
+    }
+
+    fn has_blank_line(&self, start: usize, end: usize) -> bool {
+        self.slice(start, end)
+            .bytes()
+            .filter(|byte| *byte == b'\n')
+            .count()
+            >= 2
+    }
+
+    fn raw(&self, span: Span) -> &'a str {
+        self.slice(span.start as usize, span.end as usize).trim()
+    }
+
+    fn slice(&self, start: usize, end: usize) -> &'a str {
+        &self.source[start.min(self.source.len())..end.min(self.source.len())]
+    }
+}
+
+fn binary_operator(operator: BinaryOp) -> &'static str {
+    match operator {
+        BinaryOp::Add => "+",
+        BinaryOp::Sub => "-",
+        BinaryOp::Mul => "*",
+        BinaryOp::Div => "/",
+        BinaryOp::Concat => "++",
+        BinaryOp::Equal => "==",
+        BinaryOp::NotEqual => "!=",
+        BinaryOp::Greater => ">",
+        BinaryOp::GreaterEqual => ">=",
+        BinaryOp::Less => "<",
+        BinaryOp::LessEqual => "<=",
+        BinaryOp::LogicalAnd => "&&",
+        BinaryOp::LogicalOr => "||",
+        BinaryOp::And => "&",
+        BinaryOp::Patch => "//",
+    }
+}
+
+fn compare_operator(operator: CompareOp) -> &'static str {
+    match operator {
+        CompareOp::Gt => ">",
+        CompareOp::Gte => ">=",
+        CompareOp::Lt => "<",
+        CompareOp::Lte => "<=",
+        CompareOp::Eq => "==",
+    }
+}
+
+fn same_kind(left: &SyntaxTokenKind, right: &SyntaxTokenKind) -> bool {
+    core::mem::discriminant(left) == core::mem::discriminant(right)
+}
+
+fn write_indent(out: &mut String, indent: usize) {
+    out.extend(core::iter::repeat_n(' ', indent));
+}
+
+fn ensure_line_break(out: &mut String) {
+    if !out.is_empty() && !out.ends_with('\n') {
+        out.push('\n');
+    }
+}
+
+fn ensure_blank_line(out: &mut String) {
+    if !out.is_empty() && !out.ends_with("\n\n") {
+        ensure_line_break(out);
+        out.push('\n');
+    }
+}
+
+fn trim_trailing_whitespace(out: &mut String) {
+    while out.ends_with(char::is_whitespace) {
+        out.pop();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn formats_fields_and_preserves_comments() {
+        let source =
+            "Server={\n# host\nhost=String default \"localhost\"; # trailing\n\nport=Int&>0;\n};";
+        let formatted = format_source(source).unwrap();
+        assert_eq!(
+            formatted,
+            "Server = {\n    # host\n    host = String default \"localhost\"; # trailing\n\n    port = Int & > 0;\n};\n"
+        );
+    }
+
+    #[test]
+    fn formats_arrays_and_match_comments() {
+        let source = "result=match x{# c\n_: [1,{a=2;}];};";
+        let formatted = format_source(source).unwrap();
+        assert_eq!(
+            formatted,
+            "result = match x {\n    # c\n    _: [\n        1,\n        {\n            a = 2;\n        },\n    ];\n};\n"
+        );
+    }
+
+    #[test]
+    fn formats_array_constraints() {
+        let source = "tags=[...String];ports=[...(Int&>=1)];";
+        let formatted = format_source(source).unwrap();
+        assert_eq!(
+            formatted,
+            "tags = [...String];\nports = [...(Int & >= 1)];\n"
+        );
+    }
+
+    #[test]
+    fn formats_let_functions_and_precedence_from_the_canonical_ast() {
+        let source = "value=let x=1+2*3;in(a:Int)=>{result=(x+a)*2;};";
+        let formatted = format_source(source).unwrap();
+        assert_eq!(
+            formatted,
+            "value = let\n    x = 1 + 2 * 3;\nin\n    (a: Int) =>\n        {\n            result = (x + a) * 2;\n        };\n"
+        );
+    }
+
+    #[test]
+    fn preserves_regex_and_escaped_strings() {
+        let source = r#"value={pattern=/^api\/.+$/;text="a\n\"b";};"#;
+        let formatted = format_source(source).unwrap();
+        assert!(formatted.contains(r#"pattern = /^api\/.+$/;"#));
+        assert!(formatted.contains(r#"text = "a\n\"b";"#));
+    }
+
+    #[test]
+    fn preserves_comments_inside_grouping_and_between_structural_tokens() {
+        let source = "value = (# grouped\n 1 + 2); result = match x # before brace\n { _ # before body\n : value; };";
+        let formatted = format_source(source).unwrap();
+        assert!(formatted.contains("(# grouped\n 1 + 2)"));
+        assert!(formatted.contains("match x # before brace\n{"));
+        assert!(formatted.contains("_ # before body\n : value;"));
+        assert_eq!(format_source(&formatted).unwrap(), formatted);
+    }
+
+    #[test]
+    fn wasm_export_returns_the_same_formatter_result() {
+        let source = "value={a=1;};";
+        let expected = format_source(source).unwrap();
+        let output: serde_json::Value = serde_json::from_str(&format_source_json(source)).unwrap();
+        assert_eq!(output["source"], expected);
+    }
+
+    #[test]
+    fn formats_all_repository_examples_idempotently() {
+        let examples = [
+            (
+                "advanced/main",
+                include_str!("../../../examples/advanced/main.dcdl"),
+            ),
+            (
+                "advanced/profiles",
+                include_str!("../../../examples/advanced/profiles.dcdl"),
+            ),
+            (
+                "advanced/schema",
+                include_str!("../../../examples/advanced/schema.dcdl"),
+            ),
+            (
+                "arithmetic",
+                include_str!("../../../examples/arithmetic.dcdl"),
+            ),
+            (
+                "array-concat",
+                include_str!("../../../examples/array-concat.dcdl"),
+            ),
+            (
+                "array-constraint",
+                include_str!("../../../examples/array-constraint.dcdl"),
+            ),
+            ("basic", include_str!("../../../examples/basic.dcdl")),
+            (
+                "import/main",
+                include_str!("../../../examples/import/main.dcdl"),
+            ),
+            (
+                "import/schema",
+                include_str!("../../../examples/import/schema.dcdl"),
+            ),
+            ("logical", include_str!("../../../examples/logical.dcdl")),
+            (
+                "regex/main",
+                include_str!("../../../examples/regex/main.dcdl"),
+            ),
+        ];
+        for (name, source) in examples {
+            let once = format_source(source).unwrap_or_else(|error| panic!("{name}: {error}"));
+            let twice = format_source(&once).unwrap_or_else(|error| {
+                panic!("{name} reformatted to invalid source: {error}\n{once}")
+            });
+            assert_eq!(once, twice, "{name}");
+        }
+    }
+}
@@ -0,0 +1,19 @@
+[package]
+name = "decodal-lsp"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Language Server Protocol implementation for Decodal."
+keywords = ["decodal", "lsp", "language-server", "editor"]
+categories = ["development-tools", "text-editors"]
+
+[dependencies]
+decodal = { version = "0.2.0", path = "../decodal-core" }
+decodal-language-service = { version = "0.2.0", path = "../decodal-language-service" }
+decodal-language-tools = { version = "0.2.0", path = "../decodal-language-tools" }
+lsp-server = "0.10"
+lsp-types = "0.97"
+serde_json.workspace = true
@@ -0,0 +1,11 @@
+use std::process::ExitCode;
+
+fn main() -> ExitCode {
+    match decodal_lsp::run_stdio(|_| Ok(decodal_lsp::FileSystemEnvironment::default())) {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(error) => {
+            eprintln!("decodal-lsp failed: {error}");
+            ExitCode::FAILURE
+        }
+    }
+}
@@ -0,0 +1,28 @@
+[package]
+name = "decodal-wasm"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+readme.workspace = true
+description = "Host-configurable Decodal evaluator and language service for JavaScript runtimes."
+keywords = ["decodal", "wasm", "dsl", "config"]
+categories = ["wasm", "config"]
+publish = false
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+decodal = { version = "0.2.0", path = "../decodal-core" }
+decodal-language-service = { version = "0.2.0", path = "../decodal-language-service" }
+serde_json.workspace = true
+wasm-bindgen.workspace = true
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+js-sys = "0.3"
+serde-wasm-bindgen = "0.6"
+
+[package.metadata.wasm-pack.profile.release]
+wasm-opt = false
@@ -0,0 +1,228 @@
+use decodal::{CompareOp, Constraint, HostValue, LiteralValue, PrimitiveType};
+use serde_json::{Map, Value};
+
+pub(crate) fn from_json(value: &Value) -> Result<HostValue, String> {
+    match value {
+        Value::Null => Err(String::from("null is not a Decodal host value")),
+        Value::Bool(value) => Ok(HostValue::bool(*value)),
+        Value::Number(value) => number(value),
+        Value::String(value) => Ok(HostValue::string(value)),
+        Value::Array(items) => items
+            .iter()
+            .enumerate()
+            .map(|(index, value)| {
+                from_json(value).map_err(|error| format!("array item {index}: {error}"))
+            })
+            .collect::<Result<Vec<_>, _>>()
+            .map(HostValue::array),
+        Value::Object(fields) => object(fields),
+    }
+}
+
+fn number(value: &serde_json::Number) -> Result<HostValue, String> {
+    if let Some(value) = value.as_i64() {
+        return Ok(HostValue::int(value));
+    }
+    if let Some(value) = value.as_u64() {
+        return i64::try_from(value)
+            .map(HostValue::int)
+            .map_err(|_| String::from("integer host value is outside the signed 64-bit range"));
+    }
+    value
+        .as_f64()
+        .filter(|value| value.is_finite())
+        .map(HostValue::float)
+        .ok_or_else(|| String::from("invalid numeric host value"))
+}
+
+fn object(fields: &Map<String, Value>) -> Result<HostValue, String> {
+    let Some(descriptor) = fields.get("$decodal") else {
+        return fields
+            .iter()
+            .map(|(name, value)| {
+                from_json(value)
+                    .map(|value| (name.clone(), value))
+                    .map_err(|error| format!("field `{name}`: {error}"))
+            })
+            .collect::<Result<Vec<_>, _>>()
+            .map(HostValue::object);
+    };
+
+    let descriptor = descriptor
+        .as_str()
+        .ok_or_else(|| String::from("`$decodal` must be a descriptor name"))?;
+    let constraints = parse_constraints(fields.get("constraints"))?;
+    let default = fields
+        .get("default")
+        .map(from_json)
+        .transpose()?
+        .map(Box::new);
+
+    match descriptor {
+        "String" | "Int" | "Float" | "Bool" => {
+            let primitive = match descriptor {
+                "String" => PrimitiveType::String,
+                "Int" => PrimitiveType::Int,
+                "Float" => PrimitiveType::Float,
+                "Bool" => PrimitiveType::Bool,
+                _ => unreachable!(),
+            };
+            let mut all_constraints = vec![Constraint::Type(primitive)];
+            all_constraints.extend(constraints);
+            Ok(HostValue::Abstract {
+                constraints: all_constraints,
+                default,
+            })
+        }
+        "Array" => {
+            let item = fields
+                .get("item")
+                .ok_or_else(|| String::from("Array descriptor requires `item`"))?;
+            Ok(HostValue::ArrayConstraint {
+                item: Box::new(from_json(item)?),
+                constraints,
+                default,
+            })
+        }
+        "Abstract" => Ok(HostValue::Abstract {
+            constraints,
+            default,
+        }),
+        name => Err(format!("unknown Decodal host descriptor `{name}`")),
+    }
+}
+
+fn parse_constraints(value: Option<&Value>) -> Result<Vec<Constraint>, String> {
+    let Some(value) = value else {
+        return Ok(Vec::new());
+    };
+    let items = value
+        .as_array()
+        .ok_or_else(|| String::from("`constraints` must be an array"))?;
+    items
+        .iter()
+        .enumerate()
+        .map(|(index, value)| {
+            parse_constraint(value).map_err(|error| format!("constraint {index}: {error}"))
+        })
+        .collect()
+}
+
+fn parse_constraint(value: &Value) -> Result<Constraint, String> {
+    let fields = value
+        .as_object()
+        .ok_or_else(|| String::from("constraint must be an object"))?;
+    let kind = required_string(fields, "kind")?;
+    match kind {
+        "type" => match required_string(fields, "value")? {
+            "String" => Ok(Constraint::Type(PrimitiveType::String)),
+            "Int" => Ok(Constraint::Type(PrimitiveType::Int)),
+            "Float" => Ok(Constraint::Type(PrimitiveType::Float)),
+            "Bool" => Ok(Constraint::Type(PrimitiveType::Bool)),
+            value => Err(format!("unknown primitive type `{value}`")),
+        },
+        "compare" => {
+            let operation = match required_string(fields, "op")? {
+                ">" => CompareOp::Gt,
+                ">=" => CompareOp::Gte,
+                "<" => CompareOp::Lt,
+                "<=" => CompareOp::Lte,
+                operation => return Err(format!("unknown comparison operator `{operation}`")),
+            };
+            let value = fields
+                .get("value")
+                .ok_or_else(|| String::from("compare constraint requires `value`"))?;
+            Ok(Constraint::Compare(operation, literal(value)?))
+        }
+        "regex" => Ok(Constraint::Regex(
+            required_string(fields, "value")?.to_owned(),
+        )),
+        "predicate" => Ok(Constraint::BuiltinPredicate(
+            required_string(fields, "value")?.to_owned(),
+        )),
+        kind => Err(format!("unknown constraint kind `{kind}`")),
+    }
+}
+
+fn literal(value: &Value) -> Result<LiteralValue, String> {
+    match value {
+        Value::String(value) => Ok(LiteralValue::String(value.clone())),
+        Value::Bool(value) => Ok(LiteralValue::Bool(*value)),
+        Value::Number(value) => match number(value)? {
+            HostValue::Int(value) => Ok(LiteralValue::Int(value)),
+            HostValue::Float(value) => Ok(LiteralValue::Float(value)),
+            _ => unreachable!(),
+        },
+        _ => Err(String::from("comparison value must be a primitive literal")),
+    }
+}
+
+fn required_string<'a>(fields: &'a Map<String, Value>, name: &str) -> Result<&'a str, String> {
+    fields
+        .get(name)
+        .and_then(Value::as_str)
+        .ok_or_else(|| format!("constraint requires string `{name}`"))
+}
+
+#[cfg(test)]
+mod tests {
+    use decodal::{Constraint, HostValue, LiteralValue, PrimitiveType};
+
+    use super::from_json;
+
+    #[test]
+    fn converts_plain_js_shaped_values() {
+        let value = serde_json::json!({
+            "frontmatter": { "draft": false },
+            "body": "# Hello",
+        });
+        assert_eq!(
+            from_json(&value).unwrap(),
+            HostValue::object([
+                ("body", HostValue::string("# Hello")),
+                (
+                    "frontmatter",
+                    HostValue::object([("draft", HostValue::bool(false))]),
+                ),
+            ])
+        );
+    }
+
+    #[test]
+    fn converts_schema_descriptors() {
+        let value = serde_json::json!({
+            "$decodal": "Array",
+            "item": {
+                "$decodal": "Int",
+                "constraints": [{ "kind": "compare", "op": ">", "value": 0 }],
+            },
+            "default": [1, 2],
+        });
+        assert_eq!(
+            from_json(&value).unwrap(),
+            HostValue::ArrayConstraint {
+                item: Box::new(HostValue::Abstract {
+                    constraints: vec![
+                        Constraint::Type(PrimitiveType::Int),
+                        Constraint::Compare(decodal::CompareOp::Gt, LiteralValue::Int(0)),
+                    ],
+                    default: None,
+                }),
+                constraints: Vec::new(),
+                default: Some(Box::new(HostValue::array([
+                    HostValue::int(1),
+                    HostValue::int(2),
+                ]))),
+            }
+        );
+    }
+
+    #[test]
+    fn rejects_null_values() {
+        assert!(
+            from_json(&serde_json::Value::Null)
+                .unwrap_err()
+                .contains("null")
+        );
+    }
+}
@@ -0,0 +1,263 @@
+#[cfg(target_arch = "wasm32")]
+use decodal::HostEnvironment;
+use decodal::{Data, EmptyLoader, Engine, SourceId, format_diagnostic_with};
+#[cfg(target_arch = "wasm32")]
+use decodal_language_service::{CompletionKind, LanguageService};
+use wasm_bindgen::prelude::*;
+
+#[cfg(any(target_arch = "wasm32", test))]
+mod host_value;
+#[cfg(target_arch = "wasm32")]
+mod web_environment;
+
+#[cfg(target_arch = "wasm32")]
+use web_environment::JsEnvironment;
+
+/// Evaluates one standalone Decodal source with no host globals or imports.
+#[wasm_bindgen]
+pub fn evaluate(source: &str) -> String {
+    encode_result(evaluate_inner(source))
+}
+
+/// A browser-facing language service configured entirely by its JavaScript host.
+///
+/// The host owns globals, import loading, and import completion. This keeps
+/// filesystem, network, and virtual-project policy outside the WASM package.
+#[cfg(target_arch = "wasm32")]
+#[wasm_bindgen(js_name = DecodalLanguageService)]
+pub struct WebLanguageService {
+    environment: JsEnvironment,
+}
+
+#[cfg(target_arch = "wasm32")]
+#[wasm_bindgen(js_class = DecodalLanguageService)]
+impl WebLanguageService {
+    #[wasm_bindgen(constructor)]
+    pub fn new(options: JsValue) -> Result<WebLanguageService, JsValue> {
+        Ok(Self {
+            environment: JsEnvironment::from_options(options)?,
+        })
+    }
+
+    /// Evaluates a source using the injected globals and import loader.
+    pub fn evaluate(&self, key: &str, name: &str, source: &str) -> String {
+        encode_result(evaluate_with_environment(
+            &self.environment,
+            key,
+            name,
+            source,
+        ))
+    }
+
+    /// Completes a source using the same injected environment as evaluation.
+    ///
+    /// Positions and returned ranges are UTF-16 offsets, matching browser
+    /// editors and the Language Server Protocol.
+    pub fn complete(&self, key: &str, source: &str, position: usize, explicit: bool) -> String {
+        encode_completion(&self.environment, key, source, position, explicit)
+    }
+}
+
+fn encode_result(result: Result<String, String>) -> String {
+    match result {
+        Ok(output) => serde_json::json!({ "ok": true, "output": output }).to_string(),
+        Err(error) => serde_json::json!({ "ok": false, "error": error }).to_string(),
+    }
+}
+
+fn evaluate_inner(source: &str) -> Result<String, String> {
+    let mut engine = Engine::new(EmptyLoader);
+    let module = match engine.add_root_source("playground", "playground", source) {
+        Ok(module) => module,
+        Err(error) => return Err(format_diagnostic_with_root(&error, "playground")),
+    };
+    let value = match engine.eval_module(module) {
+        Ok(value) => value,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
+    let data = match engine.materialize(&value) {
+        Ok(data) => data,
+        Err(error) => return Err(engine.format_diagnostic(&error)),
+    };
+    Ok(format_data(&data, 0))
+}
+
+#[cfg(target_arch = "wasm32")]
+fn evaluate_with_environment(
+    environment: &JsEnvironment,
+    key: &str,
+    name: &str,
+    source: &str,
+) -> Result<String, String> {
+    let mut engine = environment
+        .create_engine()
+        .map_err(|diagnostic| diagnostic.message)?;
+    let module = match engine.add_root_source(key, name, source) {
+        Ok(module) => module,
+        Err(diagnostic) => return Err(engine.format_diagnostic(&diagnostic)),
+    };
+    let value = match engine.eval_module(module) {
+        Ok(value) => value,
+        Err(diagnostic) => return Err(engine.format_diagnostic(&diagnostic)),
+    };
+    let data = match engine.materialize(&value) {
+        Ok(data) => data,
+        Err(diagnostic) => return Err(engine.format_diagnostic(&diagnostic)),
+    };
+    Ok(format_data(&data, 0))
+}
+
+#[cfg(target_arch = "wasm32")]
+fn encode_completion(
+    environment: &JsEnvironment,
+    key: &str,
+    source: &str,
+    position: usize,
+    explicit: bool,
+) -> String {
+    let byte_position = utf16_offset_to_byte(source, position);
+    let service = LanguageService::new(environment);
+    let completion = match service.complete(key, source, byte_position, explicit) {
+        Ok(completion) => completion,
+        Err(diagnostic) => {
+            return serde_json::json!({
+                "ok": false,
+                "error": diagnostic.message,
+            })
+            .to_string();
+        }
+    };
+    let completion = completion.map(|completion| {
+        let from = byte_offset_to_utf16(source, completion.from);
+        let options = completion
+            .items
+            .into_iter()
+            .map(|item| {
+                serde_json::json!({
+                    "label": item.label,
+                    "kind": completion_kind_name(item.kind),
+                    "detail": item.detail,
+                    "priority": item.priority,
+                })
+            })
+            .collect::<Vec<_>>();
+        serde_json::json!({ "from": from, "options": options })
+    });
+    serde_json::json!({ "ok": true, "completion": completion }).to_string()
+}
+
+#[cfg(target_arch = "wasm32")]
+fn completion_kind_name(kind: CompletionKind) -> &'static str {
+    match kind {
+        CompletionKind::Keyword => "keyword",
+        CompletionKind::Constant => "constant",
+        CompletionKind::Type => "type",
+        CompletionKind::Variable => "variable",
+        CompletionKind::Namespace => "namespace",
+        CompletionKind::Property => "property",
+        CompletionKind::File => "file",
+    }
+}
+
+#[cfg(any(target_arch = "wasm32", test))]
+fn utf16_offset_to_byte(source: &str, offset: usize) -> usize {
+    let mut utf16 = 0usize;
+    for (byte, ch) in source.char_indices() {
+        if utf16 >= offset {
+            return byte;
+        }
+        let next = utf16 + ch.len_utf16();
+        if next > offset {
+            return byte;
+        }
+        utf16 = next;
+    }
+    source.len()
+}
+
+#[cfg(any(target_arch = "wasm32", test))]
+fn byte_offset_to_utf16(source: &str, mut offset: usize) -> usize {
+    offset = offset.min(source.len());
+    while !source.is_char_boundary(offset) {
+        offset = offset.saturating_sub(1);
+    }
+    source[..offset].encode_utf16().count()
+}
+
+fn format_diagnostic_with_root(diagnostic: &decodal::Diagnostic, root_name: &str) -> String {
+    format_diagnostic_with(diagnostic, |source| {
+        (source == SourceId(0)).then_some(root_name)
+    })
+}
+
+fn format_data(data: &Data, indent: usize) -> String {
+    match data {
+        Data::String(value) => json_string(value),
+        Data::Int(value) => value.to_string(),
+        Data::Float(value) => value.to_string(),
+        Data::Bool(value) => value.to_string(),
+        Data::Array(items) => {
+            if items.is_empty() {
+                return String::from("[]");
+            }
+            let mut out = String::from("[\n");
+            for (index, item) in items.iter().enumerate() {
+                out.push_str(&" ".repeat(indent + 2));
+                out.push_str(&format_data(item, indent + 2));
+                if index + 1 != items.len() {
+                    out.push(',');
+                }
+                out.push('\n');
+            }
+            out.push_str(&" ".repeat(indent));
+            out.push(']');
+            out
+        }
+        Data::Object(fields) => {
+            if fields.is_empty() {
+                return String::from("{}");
+            }
+            let mut out = String::from("{\n");
+            for (index, field) in fields.iter().enumerate() {
+                out.push_str(&" ".repeat(indent + 2));
+                out.push_str(&json_string(&field.name));
+                out.push_str(": ");
+                out.push_str(&format_data(&field.value, indent + 2));
+                if index + 1 != fields.len() {
+                    out.push(',');
+                }
+                out.push('\n');
+            }
+            out.push_str(&" ".repeat(indent));
+            out.push('}');
+            out
+        }
+    }
+}
+
+fn json_string(value: &str) -> String {
+    serde_json::to_string(value).expect("strings are always JSON-serializable")
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{byte_offset_to_utf16, evaluate_inner, utf16_offset_to_byte};
+
+    #[test]
+    fn evaluates_standalone_sources() {
+        assert_eq!(
+            evaluate_inner("value = 1;").unwrap(),
+            "{\n  \"value\": 1\n}"
+        );
+    }
+
+    #[test]
+    fn converts_web_utf16_offsets() {
+        let source = "a😀β";
+        assert_eq!(utf16_offset_to_byte(source, 0), 0);
+        assert_eq!(utf16_offset_to_byte(source, 1), 1);
+        assert_eq!(utf16_offset_to_byte(source, 3), 5);
+        assert_eq!(byte_offset_to_utf16(source, 5), 3);
+        assert_eq!(byte_offset_to_utf16(source, source.len()), 4);
+    }
+}
@@ -0,0 +1,209 @@
+use std::collections::BTreeMap;
+
+use decodal::{
+    Diagnostic, DiagnosticKind, Engine, HostEnvironment, HostValue, ImportCandidate, ImportLoader,
+    LoadedImport, Span,
+};
+use js_sys::{Function, Reflect};
+use serde_json::Value;
+use wasm_bindgen::{JsCast, JsValue};
+
+use crate::host_value;
+
+pub(crate) struct JsEnvironment {
+    globals: BTreeMap<String, HostValue>,
+    load_import: Option<Function>,
+    complete_import: Option<Function>,
+}
+
+impl JsEnvironment {
+    pub(crate) fn from_options(options: JsValue) -> Result<Self, JsValue> {
+        if !options.is_null() && !options.is_undefined() && !options.is_object() {
+            return Err(JsValue::from_str(
+                "DecodalLanguageService options must be an object",
+            ));
+        }
+
+        let globals = property(&options, "globals")?;
+        let globals = if globals.is_null() || globals.is_undefined() {
+            BTreeMap::new()
+        } else {
+            let globals: Value = serde_wasm_bindgen::from_value(globals).map_err(|error| {
+                JsValue::from_str(&format!("failed to read `globals`: {error}"))
+            })?;
+            let globals = globals.as_object().ok_or_else(|| {
+                JsValue::from_str("DecodalLanguageService `globals` must be an object")
+            })?;
+            globals
+                .iter()
+                .map(|(name, value)| {
+                    host_value::from_json(value)
+                        .map(|value| (name.clone(), value))
+                        .map_err(|error| {
+                            JsValue::from_str(&format!("invalid global `{name}`: {error}"))
+                        })
+                })
+                .collect::<Result<BTreeMap<_, _>, _>>()?
+        };
+
+        Ok(Self {
+            globals,
+            load_import: optional_function(&options, "loadImport")?,
+            complete_import: optional_function(&options, "completeImport")?,
+        })
+    }
+}
+
+impl HostEnvironment for JsEnvironment {
+    type Loader = JsLoader;
+
+    fn create_loader(&self) -> Self::Loader {
+        JsLoader {
+            load_import: self.load_import.clone(),
+            complete_import: self.complete_import.clone(),
+        }
+    }
+
+    fn configure_engine(&self, engine: &mut Engine<Self::Loader>) -> decodal::Result<()> {
+        for (name, value) in &self.globals {
+            engine.bind_global(name, value.clone())?;
+        }
+        Ok(())
+    }
+}
+
+pub(crate) struct JsLoader {
+    load_import: Option<Function>,
+    complete_import: Option<Function>,
+}
+
+impl ImportLoader for JsLoader {
+    fn load(
+        &mut self,
+        current_key: Option<&str>,
+        specifier: &str,
+    ) -> decodal::Result<LoadedImport> {
+        let callback = self.load_import.as_ref().ok_or_else(|| {
+            import_error(format!(
+                "no JavaScript `loadImport` callback is configured for `{specifier}`"
+            ))
+        })?;
+        let current_key = current_key.map(JsValue::from_str).unwrap_or(JsValue::NULL);
+        let specifier = JsValue::from_str(specifier);
+        let loaded = callback
+            .call2(&JsValue::UNDEFINED, &current_key, &specifier)
+            .map_err(|error| import_error(js_error_message(error)))?;
+        let loaded: Value = serde_wasm_bindgen::from_value(loaded)
+            .map_err(|error| import_error(format!("invalid `loadImport` result: {error}")))?;
+        loaded_import(&loaded).map_err(import_error)
+    }
+
+    fn complete_import(
+        &mut self,
+        current_key: Option<&str>,
+        prefix: &str,
+    ) -> decodal::Result<Vec<ImportCandidate>> {
+        let Some(callback) = &self.complete_import else {
+            return Ok(Vec::new());
+        };
+        let current_key = current_key.map(JsValue::from_str).unwrap_or(JsValue::NULL);
+        let prefix = JsValue::from_str(prefix);
+        let candidates = callback
+            .call2(&JsValue::UNDEFINED, &current_key, &prefix)
+            .map_err(|error| import_error(js_error_message(error)))?;
+        let candidates: Value = serde_wasm_bindgen::from_value(candidates)
+            .map_err(|error| import_error(format!("invalid `completeImport` result: {error}")))?;
+        import_candidates(&candidates).map_err(import_error)
+    }
+}
+
+fn loaded_import(value: &Value) -> Result<LoadedImport, String> {
+    let fields = value
+        .as_object()
+        .ok_or_else(|| String::from("`loadImport` must return an object"))?;
+    let kind = string_field(fields, "kind")?;
+    let key = string_field(fields, "key")?;
+    match kind {
+        "source" => {
+            let source = string_field(fields, "source")?;
+            let name = fields.get("name").and_then(Value::as_str).unwrap_or(key);
+            Ok(LoadedImport::source(key, name, source))
+        }
+        "value" => {
+            let value = fields
+                .get("value")
+                .ok_or_else(|| String::from("value import requires `value`"))?;
+            let value = host_value::from_json(value)
+                .map_err(|error| format!("invalid imported value: {error}"))?;
+            Ok(LoadedImport::value(key, value))
+        }
+        kind => Err(format!("unknown `loadImport` result kind `{kind}`")),
+    }
+}
+
+fn import_candidates(value: &Value) -> Result<Vec<ImportCandidate>, String> {
+    value
+        .as_array()
+        .ok_or_else(|| String::from("`completeImport` must return an array"))?
+        .iter()
+        .enumerate()
+        .map(|(index, value)| match value {
+            Value::String(specifier) => Ok(ImportCandidate::new(specifier)),
+            Value::Object(fields) => {
+                let mut candidate = ImportCandidate::new(string_field(fields, "specifier")?);
+                if let Some(detail) = fields.get("detail") {
+                    let detail = detail.as_str().ok_or_else(|| {
+                        format!("import candidate {index} `detail` must be a string")
+                    })?;
+                    candidate = candidate.with_detail(detail);
+                }
+                Ok(candidate)
+            }
+            _ => Err(format!(
+                "import candidate {index} must be a string or object"
+            )),
+        })
+        .collect()
+}
+
+fn string_field<'a>(
+    fields: &'a serde_json::Map<String, Value>,
+    name: &str,
+) -> Result<&'a str, String> {
+    fields
+        .get(name)
+        .and_then(Value::as_str)
+        .ok_or_else(|| format!("`loadImport` result requires string `{name}`"))
+}
+
+fn property(options: &JsValue, name: &str) -> Result<JsValue, JsValue> {
+    if options.is_null() || options.is_undefined() {
+        return Ok(JsValue::UNDEFINED);
+    }
+    Reflect::get(options, &JsValue::from_str(name))
+}
+
+fn optional_function(options: &JsValue, name: &str) -> Result<Option<Function>, JsValue> {
+    let value = property(options, name)?;
+    if value.is_null() || value.is_undefined() {
+        return Ok(None);
+    }
+    value
+        .dyn_into::<Function>()
+        .map(Some)
+        .map_err(|_| JsValue::from_str(&format!("`{name}` must be a function")))
+}
+
+fn js_error_message(value: JsValue) -> String {
+    if let Some(message) = value.as_string() {
+        return message;
+    }
+    Reflect::get(&value, &JsValue::from_str("message"))
+        .ok()
+        .and_then(|message| message.as_string())
+        .unwrap_or_else(|| String::from("JavaScript import callback failed"))
+}
+
+fn import_error(message: impl Into<String>) -> Diagnostic {
+    Diagnostic::new(DiagnosticKind::Import, Span::default(), message)
+}
@@ -4,11 +4,13 @@ pkgs.mkShell {
    cargo
    clippy
    git
+    lld
    nodejs
    nixfmt
    rustc
    rustfmt
    tree-sitter
+    wasm-pack
  ];

  shellHook = ''
@@ -0,0 +1,140 @@
+# Components
+
+Decodal is split into a small runtime core and separate syntax tooling components.
+The public surface is intentionally organized by use case: execute Decodal with Rust or WebAssembly, edit Decodal on the Web with Lezer and CodeMirror, and integrate Decodal into general-purpose editors with Tree-sitter.
+
+## Runtime components
+
+### Rust crate
+
+The `decodal` crate is the primary Rust runtime and embedding API.
+It owns parsing, evaluation, materialization, diagnostics, host-provided values, and schema/decode traits.
+Rust applications should use this crate when they want to load Decodal source, evaluate it, or embed Decodal into a host program.
+
+Important paths:
+
+```text
+crates/decodal-core/
+crates/decodal-derive/
+```
+
+`decodal-derive` provides optional derive macros for Rust struct integration.
+It is a companion to the runtime crate rather than an editor or syntax-highlighting component.
+
+### WebAssembly package
+
+`decodal-wasm` exposes the runtime to browsers.
+The documentation site playground uses it to evaluate Decodal entirely in the browser.
+
+Important paths:
+
+```text
+crates/decodal-wasm/
+packages/decodal-wasm/
+```
+
+The npm package is `decodal-wasm`.
+The JSR package is `@hare/decodal-wasm`.
+
+The generated files in `packages/decodal-wasm/` are committed so the site can build without requiring every consumer to run `wasm-pack` first.
+The WebAssembly package is for execution, not syntax highlighting.
+
+## Language tools
+
+Semantic editor integration lives in the host-configurable language service crate.
+It depends only on the runtime and accepts the same `HostEnvironment` implementation used by a production application.
+The LSP crate adapts that service to the Language Server Protocol over stdin/stdout.
+It provides full document synchronization, semantic diagnostics, and whole-document formatting.
+A host-specific LSP binary injects its loader and global schema configuration without reimplementing evaluation rules.
+
+Important paths:
+
+```text
+crates/decodal-language-service/
+crates/decodal-lsp/
+```
+
+The default `decodal-lsp` binary reads Decodal imports from the filesystem.
+Embedded hosts can call its library entry point with a custom `LspEnvironment` to reuse structured imports and to make unsaved external documents, such as Markdown, visible to the loader.
+
+Source formatting lives in a separate Rust language tools crate.
+It uses the canonical Decodal AST together with the runtime lexer's lossless syntax tokens, so native LSP and WebAssembly callers execute the same formatter implementation.
+
+This component is responsible for operations that must preserve source text details such as comments and whitespace.
+It is used by the CodeMirror package's bundled formatter WebAssembly and can also be used by an LSP adapter for formatting.
+It does not depend on Tree-sitter or Lezer.
+
+Important paths:
+
+```text
+crates/decodal-language-tools/
+```
+
+The current language tools crate exposes the formatter.
+
+## Web editor components
+
+The Web playground editor uses CodeMirror 6 with a generated Lezer parser.
+Lezer provides syntax highlighting, folding, indentation, and editor syntax tree behavior. The browser formatter command calls the canonical Rust formatter compiled to WebAssembly.
+
+Important paths:
+
+```text
+editors/lezer-decodal/decodal.grammar
+packages/decodal-codemirror/src/decodal.js
+packages/decodal-codemirror/src/decodal-parser.js
+packages/decodal-codemirror/src/decodal-parser.terms.js
+packages/decodal-codemirror/src/format.js
+packages/decodal-codemirror/wasm/
+```
+
+The npm package is `decodal-codemirror`.
+The JSR package is `@hare/decodal-codemirror`.
+
+The Lezer grammar is derived from the canonical grammar documentation, but it is not a literal copy of the EBNF.
+Precedence and token conflict handling are represented in the Lezer grammar in the form CodeMirror needs.
+
+## General editor components
+
+Tree-sitter is the portable editor-integration grammar.
+Editors such as Zed, Neovim, Helix, and Emacs should consume this component when they need Decodal parsing or highlighting outside the Web playground.
+
+Important paths:
+
+```text
+editors/tree-sitter-decodal/grammar.js
+editors/tree-sitter-decodal/queries/highlights.scm
+editors/tree-sitter-decodal/queries/locals.scm
+editors/tree-sitter-decodal/src/
+```
+
+The generated parser sources under `editors/tree-sitter-decodal/src/` are committed so editor integrations can consume the grammar without regenerating it first.
+
+## Canonical grammar
+
+The human-readable grammar lives in:
+
+```text
+doc/manual/souce/language/grammar.md
+```
+
+This EBNF is the language-level reference.
+The Rust parser, Lezer grammar, and Tree-sitter grammar should be kept aligned with it, but each implementation may encode precedence and recovery behavior in the form required by its parser generator or runtime.
+
+## Syntax token API
+
+The `decodal` crate exposes `tokenize_source`, `tokenize_source_with_source_id`, `SyntaxToken`, and `SyntaxTokenKind` for source-preserving tooling.
+Comments have explicit tokens, while whitespace is represented by gaps between token spans and can be recovered from the original source.
+The evaluator parser and formatter therefore share one lexical definition without making Tree-sitter an upstream dependency.
+
+Consumers should otherwise use the component matching their environment:
+
+- Rust execution and embedding: `decodal`
+- Browser execution: `decodal-wasm`
+- Web formatting and editor syntax: canonical formatter / CodeMirror / Lezer
+- Semantic editor analysis: `decodal-language-service`
+- Language Server Protocol integration: `decodal-lsp`
+- Rust formatting: `decodal-language-tools`
+- General editor syntax: Tree-sitter
+
+Tree-sitter and Lezer remain downstream editor grammars and are not dependencies of the runtime formatter.
@@ -59,8 +59,9 @@ Config = MyConfig & {

 ## default の合成

-初期方針では、`&` による異なる default 同士の合成は conflict とする。
-同じ default は同一候補として扱ってよい。
+`&` で片方だけが default を持つ場合、その default を保持する。
+同じ thunk 由来の default 同士は同一 default として保持する。
+異なる default 同士は conflict とする。

 ```text
 merge_default(None, None) -> None
@@ -117,3 +118,9 @@ Abstract { constraints, default: None }

 materialize は default を採用する唯一の段階である。
 通常評価中に明示値が得られた場合、default は採用されない。
+
+## Diagnostic context
+
+Composition and materialization keep source spans for object fields, constraints, defaults, and thunks where possible.
+When a conflict occurs, the diagnostic should identify the operation span and related participant spans, such as the left field, right field, constraint, or default value.
+For object materialization errors, diagnostics also include the field path being processed when known.
@@ -10,10 +10,22 @@ Diagnostic {
  kind: DiagnosticKind
  span: Span
  message: String
-  notes: Vec<Note>
+  labels: Vec<DiagnosticLabel>
+  notes: Vec<String>
+}
+
+DiagnosticLabel {
+  span: Span
+  message: String
 }
 ```

+`span` は primary location を示す。
+表示時には `Span.source` を source id のまま出すのではなく、可能な限り file path や virtual file name に解決する。
+`labels` は同じ error に関係する追加 location を示す。
+`notes` は source location を持たない semantic context を示す。
+合成や materialize の失敗では、衝突した constraint、value、default、または処理中 field path を label に含める。
+
 代表的な diagnostic kind:

 - syntax error
@@ -27,6 +39,9 @@ Diagnostic {
 - match failure
 - materialization failure

+Structured imports use semantic provenance rather than synthetic source spans.
+Constraint failures report the imported value's stable key and logical field or array path alongside the source span of the Decodal constraint that rejected it.
+
 ## エラーは値ではない

 評価失敗は `RuntimeValue` ではなく `Diagnostic` を返す。
@@ -38,6 +53,18 @@ Result<RuntimeValue, Diagnostic>

 これにより、制約違反、未定義識別子、循環依存、import 失敗などが通常値として流れることを避ける。

+## 合成と materialize の diagnostic
+
+合成や materialize の失敗は、以下を示す。
+
+1. どの段階で失敗したか: composition、patch、materialization
+2. どの field path を処理中だったか
+3. どの constraint、value、default が衝突したか
+4. なぜ合成または materialize できないか
+
+例えば default が constraint を満たさない場合は、constraint の位置と default value の位置の両方を label として持つ。
+object field の合成で concrete value が衝突する場合は、左辺 field と右辺 field の位置を label として持つ。
+
 ## `try / catch` は core に入れない

 汎用 `try / catch` は core に入れない。
@@ -47,21 +74,6 @@ fallback は有限で明示的な仕組みに限定する。

 - `default`: 未指定値の fallback。
 - `match`: 有限 pattern に基づく分岐。
- optional import: ファイル不存在など、限定された失敗だけを fallback 可能にする候補。
- optional field access: field 不在だけを fallback 可能にする候補。
- union / tagged schema: 複数 schema の選択を明示的に表す将来候補。

-## optional fallback の扱い
-
-optional import や optional field access を導入する場合も、捕捉できる失敗は限定する。
-
-例として optional import は、ファイル不存在だけを fallback 可能にし、parse error や import 先の制約違反は diagnostic として報告する方がよい。
-
-```text
-optional import:
-  file not found -> fallback
-  parse error    -> diagnostic
-  eval error     -> diagnostic
-```
-
-この方針により、fallback は通常の値選択として扱い、エラー内容に依存した実行時分岐は避ける。
+Decodal は `unknown` / `any` を持たないため、field 不在や未解決 identifier を fallback 可能な通常値として扱わない。
+それらは diagnostic として報告する。
@@ -1,7 +1,7 @@
 # Embedding API

 Decodal core can be embedded without giving the core crate access to a filesystem.
-The host supplies imported sources through `SourceLoader` and may also provide global bindings through the host prelude API.
+The host supplies imports through `ImportLoader` and may also provide global bindings through the host prelude API.

 ## Host prelude

@@ -24,7 +24,7 @@ Primitive type names such as `String`, `Int`, `Float`, and `Bool` are handled be
 The host can bind values before adding or evaluating user sources.

 ```rust
-use decodal_core::{EmptyLoader, Engine, HostValue};
+use decodal::{EmptyLoader, Engine, HostValue};

 let mut engine = Engine::new(EmptyLoader);

@@ -59,12 +59,16 @@ HostValue =
  Float
  Bool
  Array(Vec<HostValue>)
+  ArrayConstraint { item, constraints, default }
  Object(Vec<HostField>)
  Abstract { constraints, default }
 ```

 When a host value is bound, the engine internalizes it into `RuntimeValue` and allocates value thunks for object fields, array items, and defaults.

+`HostValue::array_of(item)` builds an array constraint with a required element schema.
+There is no host API for an unconstrained abstract array.
+
 ## Abstract host objects

 A host-provided schema object is represented as a concrete object structure whose fields may contain abstract values.
@@ -87,11 +91,135 @@ Concrete(Object {

 This matches the runtime model used for Decodal source-defined schema objects.

-## SourceLoader and prelude together
+## Typed Rust integration

-`SourceLoader` and host prelude bindings are independent mechanisms.
+Hosts can enable the `derive` feature on `decodal` to keep a Rust struct, the Decodal schema, and the decoded result in sync.
+The derive implements two traits from the `decodal` crate:

- Use `SourceLoader` when user sources should explicitly import host-provided modules.
+- `DecodalSchema`: builds a `HostValue` schema that can be passed to `Engine::bind_global`.
+- `DecodalDecode`: decodes materialized `Data` back into the Rust type.
+
+```rust
+use decodal::{Decodal, DecodalDecode, DecodalSchema, EmptyLoader, Engine};
+
+#[derive(Decodal)]
+struct Service {
+    name: String,
+
+    #[decodal(gt = 443, default = 8443)]
+    port: i64,
+
+    #[decodal(rename = "feature.enable", default = true)]
+    feature_enabled: bool,
+}
+
+let mut engine = Engine::new(EmptyLoader);
+engine.bind_global("Service", Service::decodal_schema())?;
+
+let value = engine.eval_module(module)?;
+let data = engine.materialize(&value)?;
+let service = Service::decodal_decode(&data)?;
+```
+
+Supported field attributes are intentionally small:
+
+- `rename = "path.to.field"`
+- `default`
+- `default = value`
+- numeric constraints: `gt`, `gte`, `lt`, `lte`
+
+The derive does not add host callbacks or reflection.
+It only generates schema construction and typed decoding code.
+
+## ImportLoader and prelude together
+
+`ImportLoader` and host prelude bindings are independent mechanisms.
+
+- Use `ImportLoader` when user sources should explicitly import host-provided sources or values.
 - Use prelude bindings when host-provided schemas or constants should be globally available.

 Both mechanisms share the same runtime evaluator, thunk model, and materialization rules.
+
+## Shared host environment
+
+An embedded application can implement `HostEnvironment` to keep loader creation and global binding setup in one place.
+Both production evaluation and semantic editor tooling create their engines from this environment, preventing the editor from drifting onto a separate validation path.
+
+```rust
+use decodal::{Engine, HostEnvironment};
+
+struct AppEnvironment;
+
+impl HostEnvironment for AppEnvironment {
+    type Loader = ContentLoader;
+
+    fn create_loader(&self) -> Self::Loader {
+        ContentLoader::new()
+    }
+
+    fn configure_engine(
+        &self,
+        engine: &mut Engine<Self::Loader>,
+    ) -> decodal::Result<()> {
+        engine.bind_global("Site", site_schema())?;
+        Ok(())
+    }
+}
+
+let environment = AppEnvironment;
+let mut engine = environment.create_engine()?;
+```
+
+The semantic service accepts the same environment by value:
+
+```rust
+use decodal_language_service::LanguageService;
+
+let service = LanguageService::new(&environment);
+let analysis = service.analyze("site.dcdl", "site.dcdl", source);
+```
+
+Each analysis uses a fresh engine and runs the normal parse, evaluate, and materialize pipeline.
+An environment may create loaders backed by shared filesystem, database, or editor-overlay state when repeated analysis needs a current workspace snapshot.
+
+The LSP adapter constructs that environment after receiving the client's initialization parameters:
+
+```rust
+use decodal_lsp::{LspEnvironment, run_stdio};
+
+impl LspEnvironment for AppEnvironment {}
+
+run_stdio(|initialize| {
+    let _ = initialize;
+    Ok(AppEnvironment)
+})?;
+```
+
+`LspEnvironment` adds document lifecycle hooks on top of `HostEnvironment`.
+A `run_stdio` environment factory always receives the client's `InitializeParams`; the host decides whether to use its workspace folders, initialization options, and capabilities or ignore them.
+A host that keeps unsaved buffers in shared state can update them from `open_document`, `change_document`, and `close_document`; every subsequent diagnostic pass creates the normal import loader from that updated environment.
+Synchronized non-Decodal documents are passed through these hooks but are not evaluated as Decodal roots, so a loader can parse an unsaved Markdown file into `HostValue` and immediately revalidate the open Decodal documents that import it.
+
+## Structured imports
+
+`ImportLoader::load` returns either `LoadedImport::Source` or `LoadedImport::Value`.
+The value variant carries a `HostValue`, allowing a host to parse non-Decodal resources such as Markdown into an application-specific structure.
+
+```text
+import "./post.md"
+  -> host parses content
+  -> LoadedImport::Value(
+       { frontmatter: {...}, body: "..." }
+     )
+  -> Engine internalizes HostValue
+  -> normal composition and materialization
+```
+
+The core does not select content types or bundle Markdown/frontmatter parsers.
+The loader owns path resolution, media or extension dispatch, parsing rules, and parse diagnostics.
+The stable loader key is also used to cache structured imports.
+
+When a structured value fails a Decodal constraint, the diagnostic keeps the Decodal constraint span and identifies the host value by its stable import key and logical value path, such as `content/post.md` and `frontmatter.draft`.
+`HostValue` does not need source spans: syntax diagnostics for the external format remain the loader's responsibility, while cross-value validation reports semantic provenance.
+
+`load` is the single import hook: loaders dispatch by extension, media type, or another host-defined rule and return the appropriate variant directly.
@@ -23,6 +23,9 @@ materialize
 data / diagnostics
 ```

+Production applications and semantic language services can construct this pipeline through the same host-defined `HostEnvironment`.
+The environment creates the `ImportLoader` and installs host globals before the root module is registered.
+
 ## lexer / parser

 lexer / parser は source を AST に変換する。
@@ -66,14 +69,16 @@ ModuleRegistry:
 処理系は、まず root module を parse / desugar して registry に登録する。
 import 先 module は、この段階で全て読み込む必要はない。

-import expression が評価されたとき、処理系は `SourceLoader` に現在の module key と import specifier を渡す。
-loader は module key、表示名、source text を返す。
-module registry は key が未登録なら対象 module を parse / desugar して登録する。
-登録された module は module root thunk を持つ。
-同じ module が複数回 import された場合は、同じ `ModuleId` を返す。
+import expression が評価されたとき、処理系は `ImportLoader::load` に現在の module key と import specifier を渡す。
+loader は module key、表示名、および DCDL source text または構造化済み `HostValue` を返す。
+DCDL source の場合、module registry は key が未登録なら対象 module を parse / desugar して登録する。
+登録された source module は module root thunk を持つ。
+構造化値の場合、host value を runtime value に internalize した root thunk を key でキャッシュする。
+同じ key が複数回 import された場合は、同じ source module または structured root thunk を使う。

-つまり import は module を即時評価しない。
+つまり source import は module を即時評価しない。
 module を読み込み、module root を thunk として登録するだけにする。
+structured import も root value を thunk として保持し、object field や array item の既存 thunk model を利用する。

 AST の `ExprId` は module-local である。
 そのため runtime が保持する式参照は `ExprRef { module, expr }` として module-qualified にする。
@@ -1,10 +1,43 @@
 # Features

-Decodal keeps the embedded core small by making heavy functionality opt-in.
+Decodal は embedded use と小さい runtime を優先する。
+言語機能を追加するときは、値の合成・検証・materialization に直接必要なものを core に残し、重い依存や高度な推論は optional feature または外部 tooling に分ける。
+
+## Core feature boundary
+
+Core に入れる機能は、基本的に deterministic な value transformation に限る。
+
+- arithmetic / logical / comparison operators
+- array concat
+- object / constraint composition
+- default materialization
+- pure function evaluation
+- host supplied import evaluation
+
+Core に入れないものは以下である。
+
+- filesystem / network / environment access
+- time / random
+- mutation
+- reflection or existence probing
+- arbitrary host function calls
+- symbolic constraint solving beyond simple normalization
+
+未解決 identifier や missing field は `unknown` として流れず、diagnostic になる。
+この方針により、存在チェックや optional chaining のような dynamic object inspection は core language の対象外とする。
+
+## Constraint reasoning
+
+Constraint normalization は軽量な範囲に留める。
+primitive type conflict や明らかな numeric bound conflict は合成時に検出してよい。
+一方で、symbolic arithmetic、boolean algebra、regex intersection、array length dependent typing のような重い推論は行わない。
+
+評価済みの concrete value に対する検証は runtime / materialization で行う。
+静的に完全な型検査フェーズを増やすのではなく、parse、evaluate、compose、materialize の各段階で自然に分かる error を diagnostic として返す。

 ## Core defaults

-`decodal-core` defaults to `std` only.
+`decodal` defaults to `std` only.

 ```toml
 [features]
@@ -13,7 +46,7 @@ std = []
 regex = ["std", "dep:regex"]
 ```

-Building `decodal-core` with `--no-default-features` keeps the core in `no_std + alloc` mode and avoids optional dependencies.
+Building `decodal` with `--no-default-features` keeps the core in `no_std + alloc` mode and avoids optional dependencies.

 ## Regex

@@ -21,7 +54,7 @@ Regex constraints are implemented behind the `regex` feature.
 When the feature is disabled, regex constraints parse and compose, but validating a concrete value against them returns an unsupported feature diagnostic.

 ```sh
-cargo run -q -p decodal --features regex -- examples/regex/main.dcdl
+cargo run -q -p decodal-cli --features regex -- examples/regex/main.dcdl
 ```

 Regex constraints are accumulated during `&` composition.
@@ -30,5 +63,5 @@ Concrete strings must match every regex constraint attached to the abstract valu

 ## CLI features

-`decodal-cli` exposes a matching `regex` feature that enables `decodal-core/regex`.
+`decodal-cli` exposes a matching `regex` feature that enables `decodal/regex`.
 The feature is not enabled by default so the default CLI binary remains small.
@@ -14,6 +14,10 @@ RuntimeValue =
 `Concrete` は明示的な値である。
 `Abstract` は、まだ具体値に確定していない制約付きの値である。

+Decodal は `unknown`、`any`、`null` のような「存在するが意味が未確定な値」を runtime value として持たない。
+識別子や field が解決できない場合は、その場で diagnostic になる。
+未解決値を後続の演算へ流して推論することはしない。
+
 ## ConcreteValue

 ```text
@@ -32,7 +36,11 @@ object は concrete structure として扱う。

 ```text
 ObjectValue:
-  fields: Map<Symbol, ThunkId>
+  fields: Map<Symbol, ObjectField>
+
+ObjectField:
+  value: ThunkId
+  span: Span
 ```

 例えば以下の schema object は、object 自体は concrete だが、field の値は abstract value になる。
@@ -57,9 +65,14 @@ Concrete(Object {

 ```text
 AbstractValue {
-  constraints: Vec<Constraint>
+  constraints: Vec<ConstraintEntry>
  default: Option<ThunkId>
 }
+
+ConstraintEntry {
+  constraint: Constraint
+  span: Span
+}
 ```

 `default` は `AbstractValue` にだけ存在する。
@@ -88,6 +101,21 @@ port = 8000;
 Concrete(Int(8000))
 ```

+## Runtime scope
+
+Decodal runtime は application runtime ではなく、pure value evaluator である。
+同じ source、同じ import results、同じ host globals が与えられた場合、評価結果は決定的である。
+
+runtime が扱う責務は以下に限る。
+
+- expression を評価する。
+- thunk を必要に応じて force する。
+- concrete / abstract value を合成する。
+- materialize 時に constraint を検証する。
+
+runtime は filesystem、network、environment variable、time、random、mutation を扱わない。
+core における import は host supplied source または structured value を受け取る境界であり、filesystem access ではない。
+
 ## Constraint

 constraint は concrete value とは別の型として扱う。
@@ -95,12 +123,16 @@ constraint は concrete value とは別の型として扱う。
 ```text
 Constraint =
  Type(PrimitiveType)
+  ArrayItems(ThunkId)
  Compare(Op, Literal)
  Regex(Pattern)
  BuiltinPredicate(Symbol)
  ObjectConstraint(...)
 ```

+`ArrayItems` は配列そのものの型と、すべての要素へ合成する schema thunk を表す。
+配列用の primitive type は持たず、抽象配列には必ず要素制約が必要である。
+
 初期実装では、object の形は主に `Concrete(Object)` の field に `Abstract` を置くことで表現する。
 object 全体にかかる constraint は必要になった時点で追加する。

@@ -84,5 +84,5 @@ module root や field は thunk として保持され、参照されたときだ
 関数引数は thunk として関数の environment に束縛する。
 関数本体で引数が参照されたときだけ force する。

-任意の関数呼び出し結果をグローバルに memoize する必要はない。
+関数呼び出し結果そのものはグローバルには memoize しない。
 field に束縛された関数呼び出し結果は、その field thunk の評価結果として memoize される。
@@ -9,15 +9,158 @@ Run the normal Rust checks from the repository root.
 ```sh
 cargo fmt --check
 cargo test
-cargo check -p decodal-core --no-default-features
+cargo check -p decodal --no-default-features
 nix flake check
 ```

+Run the default stdio language server with:
+
+```sh
+cargo run -q -p decodal-lsp
+```
+
+The protocol integration tests use an in-memory LSP connection and can be run independently:
+
+```sh
+cargo test -p decodal-lsp
+```
+
 Regex support is optional and should be tested explicitly when touched.

 ```sh
-cargo test -p decodal-core --features regex
-cargo run -q -p decodal --features regex -- examples/regex/main.dcdl
+cargo test -p decodal --features regex
+cargo run -q -p decodal-cli --features regex -- examples/regex/main.dcdl
+```
+
+## crates.io release
+
+The crates.io release contains `decodal`, `decodal-derive`, `decodal-language-service`, `decodal-language-tools`, and `decodal-lsp`.
+`decodal-cli` and the Rust source crate `decodal-wasm` remain repository-only packages.
+The generated WebAssembly package under `packages/decodal-wasm/` is published to npm and JSR.
+The CodeMirror package bundles the generated formatter WebAssembly from `decodal-language-tools`.
+The project is dual licensed as `MIT OR Apache-2.0`.
+
+The authoritative validation commands, dependency order, and publish commands are maintained in `RELEASING.md` at the repository root.
+
+## Web site and playground
+
+The Astro documentation site and browser playground are kept in:
+
+```text
+site/decodal-site/
+```
+
+The site imports Markdown files from `doc/manual/souce/` and renders them as mdBook-style pages.
+The playground loads `decodal-wasm` for evaluation and `decodal-codemirror` for editor features and source formatting.
+
+Important files:
+
+```text
+site/decodal-site/src/pages/docs/[...slug].astro
+site/decodal-site/src/pages/playground.astro
+site/decodal-site/src/scripts/playground.js
+site/decodal-site/src/scripts/playground-examples.js
+site/decodal-site/src/layouts/ManualLayout.astro
+site/decodal-site/src/lib/docs.js
+site/decodal-site/src/lib/highlight.js
+packages/decodal-codemirror/src/decodal.js
+packages/decodal-codemirror/src/decodal-parser.js
+packages/decodal-wasm/decodal_wasm.js
+packages/decodal-wasm/decodal_wasm_bg.wasm
+packages/decodal-codemirror/wasm/decodal_language_tools.js
+packages/decodal-codemirror/wasm/decodal_language_tools_bg.wasm
+crates/decodal-wasm/src/lib.rs
+crates/decodal-language-tools/src/lib.rs
+```
+
+Build the WebAssembly packages before building the site:
+
+```sh
+cd site/decodal-site
+npm install
+npm run build:wasm
+npm run build
+```
+
+`npm run build:wasm` builds both generated WebAssembly packages.
+`npm run build:wasm:runtime` writes generated runtime files into `packages/decodal-wasm/`.
+`npm run build:wasm:formatter` writes generated formatter files into `packages/decodal-codemirror/wasm/`.
+`npm run build` builds only the static site from the current package files.
+Use `npm run build:all` to regenerate both WebAssembly packages and then build the static site in one command.
+
+These generated files are committed so the site can be built without requiring every consumer to regenerate the wasm packages first.
+
+Publish the generated WebAssembly package from its package directory:
+
+```sh
+cd packages/decodal-wasm
+npm publish
+npx jsr publish
+```
+
+Run dry-runs first when preparing a release:
+
+```sh
+npm pack --dry-run
+npx jsr publish --dry-run
+```
+
+The npm package name is `decodal-wasm`.
+The JSR package name is `@hare/decodal-wasm`.
+The npm package advertises `MIT OR Apache-2.0`; JSR metadata uses `MIT` because its publisher requires a single recognized license identifier. Both license files are included in the package.
+
+The playground editor uses the `decodal-codemirror` package with the generated Lezer parser in `packages/decodal-codemirror/src/decodal-parser.js`.
+The canonical grammar is documented in `doc/manual/souce/language/grammar.md`; regenerate the Lezer parser when that grammar or `editors/lezer-decodal/decodal.grammar` changes.
+
+Publish the CodeMirror package from its package directory:
+
+```sh
+cd packages/decodal-codemirror
+npm install
+npm publish
+npx jsr publish
+```
+
+Run dry-runs first when preparing a release:
+
+```sh
+npm install
+npm pack --dry-run
+npx jsr publish --dry-run
+```
+
+The npm package name is `decodal-codemirror`.
+The JSR package name is `@hare/decodal-codemirror`.
+As with `decodal-wasm`, JSR metadata uses `MIT` while both the MIT and Apache-2.0 license files remain included.
+
+The documentation build still uses the lightweight JavaScript fallback highlighter so Astro can render Markdown without initializing WASM at build time.
+
+To run the site locally:
+
+```sh
+cd site/decodal-site
+npm run dev
+```
+
+Deploy the static site to Cloudflare Pages with Wrangler direct upload:
+
+```sh
+cd site/decodal-site
+npm run deploy
+```
+
+The deploy script runs `npm run build` and then uploads `dist/` to the Pages project named `decodal-site` on branch `master`.
+Cloudflare Pages treats this as production when the project production branch is `master`.
+Use `CLOUDFLARE_PROJECT_NAME` when deploying to a differently named Pages project.
+
+```sh
+CLOUDFLARE_PROJECT_NAME=my-pages-project npm run deploy
+```
+
+If the committed WASM package must be regenerated before deploy, use:
+
+```sh
+npm run deploy:all
 ```

 ## Tree-sitter grammar
@@ -64,16 +207,22 @@ The generated parser files under `editors/tree-sitter-decodal/src/` are committe

 When the Decodal syntax changes:

-1. Update `grammar.js`.
-2. Run `npx tree-sitter generate`.
-3. Add or update corpus tests in `corpus/`.
-4. Update highlight queries in `queries/highlights.scm` if token names changed.
-5. Run `npx tree-sitter test`.
-6. Run Rust checks from the repository root if the language parser or examples also changed.
+1. Update the canonical EBNF in `doc/manual/souce/language/grammar.md`.
+2. Update the Rust parser/lexer as needed.
+3. Update `editors/tree-sitter-decodal/grammar.js` and run `npx tree-sitter generate` / `npx tree-sitter test`.
+4. Update `editors/lezer-decodal/decodal.grammar` and regenerate the CodeMirror parser:
+
+```sh
+cd site/decodal-site
+npx lezer-generator ../../editors/lezer-decodal/decodal.grammar -o ../../packages/decodal-codemirror/src/decodal-parser.js
+```
+
+5. Add or update corpus/tests/examples.
+6. Run Rust and site checks from the repository root.

 ## Development shell

-The Nix development shell includes Rust tooling, Node.js, and Tree-sitter CLI tooling.
+The Nix development shell includes Rust tooling, Node.js, Tree-sitter CLI tooling, and wasm-pack tooling.

 ```sh
 nix develop
@@ -87,5 +236,7 @@ The shell provides:
 - `clippy`
 - `node`
 - `npm`
+- `wasm-pack`
+- `lld`
 - `tree-sitter`
 - `nixfmt`
@@ -6,7 +6,8 @@ Decodal は Deferred Constraint Data Language、略称 DCDL のプロジェク
 ## 目次

 1. [Introduction](./introduction.md)
-2. [Language Specification](./language/index.md)
+2. [Components](./components.md)
+3. [Language Specification](./language/index.md)
   1. [Lexical Structure and Syntax](./language/syntax.md)
   2. [Value](./language/value/index.md)
      1. [String](./language/value/string.md)
@@ -35,7 +36,7 @@ Decodal は Deferred Constraint Data Language、略称 DCDL のプロジェク
   9. [Materialization and Errors](./language/materialization-and-errors.md)
   10. [Naming Conventions](./language/naming.md)
   11. [Examples](./language/examples.md)
-3. [Implementation Design](./design/index.md)
+4. [Implementation Design](./design/index.md)
   1. [Execution Pipeline](./design/execution-pipeline.md)
   2. [Runtime Model](./design/runtime-model.md)
   3. [Thunk and Lazy Evaluation](./design/thunk-and-lazy-evaluation.md)
@@ -43,5 +44,5 @@ Decodal は Deferred Constraint Data Language、略称 DCDL のプロジェク
   5. [Diagnostics and Fallback](./design/diagnostics-and-fallback.md)
   6. [Embedding API](./design/embedding-api.md)
   7. [Features](./design/features.md)
-4. [Development](./development.md)
-5. [Open Issues](./open-issues.md)
+5. [Development](./development.md)
+6. [Open Issues](./open-issues.md)
@@ -124,6 +124,19 @@ String & /^a$/ & /^b$/
 Host = IPv4Address;
 ```

+## 配列制約
+
+配列制約には要素制約が必須であり、`[...T]` と書く。
+
+```dcdl
+Names = [...String];
+PositiveInts = [...(Int & > 0)];
+```
+
+複数の配列制約を `&` で合成した場合、各 concrete 要素へすべての要素制約を合成する。
+要素が object schema の場合は、その schema に含まれる default も各要素へ適用される。
+要素制約のない `Array` primitive type は存在しない。
+
 ## default

 `default` は制約ではない。
@@ -188,11 +201,12 @@ RuntimeValue =

 ## default の合成

-同じフィールドに複数の `default` が合成された場合の詳細規則は未確定である。
-現時点の単純な方針は以下である。
+`default` の合成規則は以下である。

- `&` による default 同士の衝突はエラーにする。
- 同一 default 値は許可してよい。
- `//` による patch では右辺 default が左辺 default を置き換える。
+- `&` で片方だけが default を持つ場合、その default を保持する。
+- `&` で両方が異なる default を持つ場合、conflict になる。
+- `Abstract & Concrete` が成功した場合、結果は concrete value になり default は消える。
+- `//` では右辺が左辺を置き換える。object/object の場合は field ごとに再帰 patch されるため、右辺 field の default が左辺 field の default を置き換える。

-この方針により、`&` は制約を保った合成、`//` は上書き操作として説明できる。
+`default` thunk は materialize 時に必要になった時点で評価する。
+評価された default value は、同じ abstract value に残っている制約を満たす必要がある。
@@ -74,5 +74,5 @@ Error        評価失敗
 関数引数は thunk として渡せる。
 関数本体内で引数が参照されたときに評価する。

-任意の関数呼び出し結果をグローバルに memoize することは必須ではない。
+関数呼び出し結果そのものはグローバルには memoize しない。
 ただし、フィールドに束縛された呼び出し結果は、そのフィールド thunk の評価結果として memoize される。
@@ -5,21 +5,19 @@
 ## 基本的な設定スキーマ

 ```dcdl
-rec {
-    Host = IPv4Address;
+Host = IPv4Address;

-    Port = Int & >= 1 & <= 65535;
-    NarrowedPort = Port & > 443;
+Port = Int & >= 1 & <= 65535;
+NarrowedPort = Port & > 443;

-    MyConfig = {
-        host = Host;
-        port = NarrowedPort default 8080;
-        feature_hoge = {
-            enable = Bool default true;
-            fuga = Int default 10;
-        };
+MyConfig = {
+    host = Host;
+    port = NarrowedPort default 8080;
+    feature_hoge = {
+        enable = Bool default true;
+        fuga = Int default 10;
    };
-}
+};

 NewConfig = MyConfig & {
    host = "127.0.0.1";
@@ -33,28 +31,37 @@ disabled_config = NewConfig & {
 enabled_config = NewConfig;
 ```

-## 関数と文字列生成
+## 配列スキーマ
+
+```dcdl
+Services = [...{
+    name = String;
+    port = Int default 8080;
+}];
+
+Services & [
+    { name = "api"; },
+    { name = "worker"; port = 9000; },
+]
+```
+
+抽象配列には要素制約が必須である。
+この例では、1 番目の要素の `port` は `8080` に materialize される。
+
+## 関数と制約

 ```dcdl
 let
-    maybe_hw = String & /Hello! .*/;
-    part = {
-        greet = String;
-        target = String;
-    };
-    mk_hw = (part: part) =>
-        maybe_hw & "${part.greet}! ${part.target}";
+    Port = Int & >= 1 & <= 65535;
+    add_offset = (base: Port, offset: Int) => base + offset;
 in
-    mk_hw({
-        greet = "Hello";
-        target = "World";
-    })
+    add_offset(8000, 80)
 ```

 評価結果:

 ```text
-"Hello! World"
+8080
 ```

 ## match
@@ -0,0 +1,43 @@
+# Arithmetic Expression
+
+Decodal supports arithmetic over concrete numeric values.
+
+```dcdl
+{
+    workers = 2 + 2;
+    timeout = 30.0 / 2;
+    port = 8000 + 80;
+    negative = -1;
+}
+```
+
+## Operators
+
+- `+` addition
+- `-` subtraction
+- `*` multiplication
+- `/` division
+- unary `-` negation
+
+`*` and `/` bind tighter than `+` and `-`.
+Parentheses can be used to make grouping explicit.
+
+```dcdl
+2 + 3 * 4     # 14
+(2 + 3) * 4   # 20
+```
+
+## Numeric behavior
+
+Arithmetic requires concrete `Int` or `Float` operands.
+`Int + Int`, `Int - Int`, and `Int * Int` produce `Int` when no overflow occurs.
+Mixed `Int` / `Float` arithmetic produces `Float`.
+Division always produces `Float`.
+
+Division by zero and integer overflow are evaluation errors.
+
+Arithmetic expressions can be used anywhere a concrete numeric expression is expected, including defaults and numeric constraints.
+
+```dcdl
+port = Int & > 4000 + 42 default 8080;
+```
@@ -7,9 +7,61 @@ array expression は、順序付きの値の列を表す。
 ["a", "b", "c"]
 ```

-## 未確定事項
+配列リテラルは concrete value であり、要素型を揃える必要はない。

- 配列要素の制約表現。
- 異種配列を許可するか。
- `//` による patch を右辺置換だけにするか。
- append / prepend / remove などの操作を提供するか。
+```dcdl
+["api", 8080, true]
+```
+
+## Array constraint
+
+配列制約は `[` の直後に ellipsis を置き、その後へ要素制約を記述する。
+
+```dcdl
+Names = [...String];
+Ports = [...(Int & >= 1 & <= 65535)];
+```
+
+`[...T]` は、すべての要素が `T` を満たす長さ 0 以上の配列を表す。
+空配列は任意の配列制約を満たす。
+
+```dcdl
+[...String] & []
+[...String] & ["api", "worker"]
+```
+
+要素制約は object schema にもできる。
+要素 schema の default は、配列へ制約を合成するときに各要素へ適用される。
+
+```dcdl
+Services = [...{
+    name = String;
+    enabled = Bool default true;
+}];
+
+Services & [{ name = "api"; }]
+```
+
+要素制約のない抽象配列型は提供しない。
+旧来の `Array` primitive type は使用できず、`[...T]` の `T` は必須である。
+`[String]` は配列制約ではなく、未解決の `String` 制約を 1 要素に持つ concrete array になる。
+長さ制約、位置別の tuple 制約、unique 制約は現在サポートしない。
+
+## Array concat
+
+`++` は concrete array 同士を連結する。
+
+```dcdl
+base = ["read", "write"];
+extra = ["admin"];
+roles = base ++ extra;
+```
+
+`roles` は以下と同じ値になる。
+
+```dcdl
+["read", "write", "admin"]
+```
+
+`++` は配列要素を変換しない。
+左辺の要素の後に右辺の要素が並ぶ。
@@ -3,10 +3,7 @@
 function call expression は、関数値を引数に適用する式である。

 ```dcdl
-mk_hw({
-    greet = "Hello";
-    target = "World";
-})
+increment(41)
 ```

 ## 評価
@@ -14,4 +11,5 @@ mk_hw({
 引数は thunk として渡せる。
 関数本体内で引数が参照されたときに評価する。

-任意の関数呼び出し結果をグローバルに memoize することは必須ではない。
+関数呼び出し結果そのものはグローバルには memoize しない。
+フィールドに束縛された呼び出し結果は、そのフィールド thunk の評価結果として memoize される。
@@ -3,11 +3,7 @@
 function expression は、引数を受け取り式を返す値である。

 ```dcdl
-(part: {
-    greet = String;
-    target = String;
-}) =>
-    "${part.greet}! ${part.target}"
+(value: Int) => value + 1
 ```

 関数仕様の詳細は [関数](../functions.md) に置く。
@@ -11,6 +11,7 @@ Expr
 ├─ path reference
 ├─ object
 ├─ array
+├─ array constraint
 ├─ function
 ├─ function call
 ├─ let
@@ -4,12 +4,10 @@ let expression は、ローカル束縛を作る。

 ```dcdl
 let
-    part = {
-        greet = "Hello";
-        target = "World";
-    };
+    base = 8000;
+    offset = 80;
 in
-    "${part.greet}! ${part.target}"
+    base + offset
 ```

 ## 評価
@@ -0,0 +1,41 @@
+# Logical and Comparison Expressions
+
+Decodal supports boolean logic over concrete `Bool` values and comparison over concrete scalar values.
+
+```dcdl
+{
+    is_prod = env == "prod";
+    high_port = port > 9000;
+    enabled = is_prod && high_port;
+    disabled = !enabled;
+}
+```
+
+## Logical operators
+
+- `!expr` negates a concrete `Bool`.
+- `lhs && rhs` returns boolean AND.
+- `lhs || rhs` returns boolean OR.
+
+`&&` and `||` short-circuit: the right-hand side is evaluated only when needed.
+Logical operands must evaluate to concrete `Bool` values.
+
+## Comparison operators
+
+- `==`
+- `!=`
+- `<`
+- `<=`
+- `>`
+- `>=`
+
+`==` and `!=` compare concrete scalar values: `String`, `Bool`, `Int`, and `Float`.
+`Int` and `Float` can be compared to each other numerically.
+
+Ordering operators `<`, `<=`, `>`, and `>=` compare concrete numeric values only.
+They are separate from prefix comparison constraints such as `> 443`.
+
+```dcdl
+port = Int & > 443 default 9443;
+is_high = port > 9000;
+```
@@ -12,4 +12,5 @@ config.feature_hoge.enable
 左側の式を object として評価し、指定された field を参照する。
 参照先 field は必要になるまで評価されない。

-存在しない field への参照をエラーにするか、open schema として扱うかは未確定である。
+存在しない field への参照は diagnostic になる。
+Decodal は unknown / Any のような値を伝播せず、field の有無を曖昧にしない。
@@ -1,12 +1,8 @@
-# String Interpolation Expression
+# String Interpolation

-string interpolation は、文字列内に式を埋め込む候補機能である。
+文字列補間は初期実装には含めない。

-```dcdl
-"${part.greet}! ${part.target}"
-```
+Decodal の string literal は、現時点では literal text として扱う。
+式を埋め込む構文は定義しない。

-## 評価
-
-補間式の評価タイミングは通常の遅延評価に従う。
-文字列補間を初期実装に含めるかは未確定である。
+必要になった場合は、文字列連結や明示的な formatting function として別途設計する。
@@ -5,54 +5,47 @@
 ## 構文

 ```dcdl
-(part: {
-    greet = String;
-    target = String;
-}) =>
-    "${part.greet}! ${part.target}"
+(value: Int) => value + 1
 ```

 関数呼び出しは通常の呼び出し構文で行う。

 ```dcdl
-mk_hw({
-    greet = "Hello";
-    target = "World";
-})
+let
+    increment = (value: Int) => value + 1;
+in
+    increment(41)
 ```

-複数引数の構文は候補として以下を想定する。
+複数引数も指定できる。

 ```dcdl
-(
-    input_a: {
-        hoge = Int & >= 0;
-    },
-    input_b: {
-        fuga = 20;
-    }
-) =>
+(input_a: { hoge = Int & >= 0; }, input_b: { fuga = Int; }) =>
 {
-    # ...
+    hoge = input_a.hoge;
+    fuga = input_b.fuga;
 }
 ```

 ## 関数の意味

-関数は値として扱える。
-ただし、最終データとして関数値を出力できるかどうかは別途定める。
-設定ファイルを materialize する段階では、未適用の関数値は出力不能な値として扱うのが自然である。
+関数は runtime value として扱えるが、最終データとして materialize することはできない。
+未適用の関数値が materialize 対象に残っている場合は diagnostic になる。
+
+関数値は opaque であり、関数値同士の等価性は提供しない。
+`&` で関数値同士を合成すると conflict になる。

 ## 評価方針

-関数は以下の方針を基本とする。
+関数は以下の方針で評価する。

 - 関数は純粋である。
 - 関数はレキシカルスコープを持つ。
 - 関数は定義時の環境を参照として保持する。
- 引数は必要になるまで評価しない。
- フィールドに束縛された関数呼び出し結果は、そのフィールド評価結果として memoize される。
- 任意の関数呼び出しそのものをグローバルに memoize することは必須ではない。
+- 引数は thunk として渡され、必要になるまで評価されない。
+- 関数呼び出し結果そのものはグローバルには memoize しない。
+- フィールドに束縛された関数呼び出し結果は、そのフィールド thunk の評価結果として memoize される。
+- 再帰的な依存は thunk cycle として diagnostic になる。

 関数値の内部モデル例:

@@ -63,29 +56,3 @@ Function {
  env: EnvRef
 }
 ```
-
-## 関数と重さ
-
-関数の文法・パーサー自体は大きくない。
-実装上の重さは、主に評価モデルと意味論から発生する。
-
-注意点:
-
- クロージャが環境を掴む。
- 引数を lazy にするか strict にするかを決める必要がある。
- 関数呼び出し結果をどこまで memoize するかを決める必要がある。
- 再帰関数を許可するかを決める必要がある。
- 関数値同士の `&` をどう扱うかを決める必要がある。
- 関数値を object に入れたとき、materialize 可能かを決める必要がある。
- import 循環と関数適用が絡んだときの cycle detection が必要になる。
-
-軽量に保つため、初期仕様では以下の制限を検討できる。
-
- 関数は pure。
- lexical closure は許可。
- 引数は thunk として渡す。
- 関数本体は必要になるまで評価しない。
- 関数値は opaque。
- 関数同士の `&` は、同一関数参照以外は conflict。
- 関数値は最終データとして出力できない。
- 再帰は cycle error として扱う、または v1 では禁止する。
@@ -0,0 +1,113 @@
+# Grammar
+
+This page is the canonical grammar reference for Decodal syntax.
+Parser implementations such as the Rust parser, Tree-sitter grammar, and Lezer grammar should follow this grammar and may add implementation-specific precedence annotations where needed.
+
+## Lexical grammar
+
+```ebnf
+source_character = ? any Unicode scalar value ? ;
+newline          = "\n" | "\r\n" | "\r" ;
+space            = " " | "\t" | newline ;
+comment          = "#" , { ? any character except newline ? } ;
+
+digit            = "0" … "9" ;
+letter           = "A" … "Z" | "a" … "z" ;
+identifier       = letter , { letter | digit | "_" } ;
+
+integer          = digit , { digit } ;
+float            = digit , { digit } , "." , digit , { digit } ;
+
+string           = '"' , { string_character | escape } , '"' ;
+string_character = ? any character except '"', "\\", or newline ? ;
+escape           = "\\" , source_character ;
+
+regex            = "/" , regex_character , { regex_character } , "/" ;
+regex_character  = escape | ? any character except "/", "\\", or newline ? ;
+```
+
+Whitespace and comments separate tokens and are otherwise ignored by the parser.
+
+## Syntactic grammar
+
+```ebnf
+module          = { statement } ;
+statement       = field_definition , [ ";" ]
+                | expression , [ ";" ] ;
+
+expression      = default_expression ;
+
+default_expression = patch_expression , [ "default" , default_expression ] ;
+patch_expression   = compose_expression , { "//" , compose_expression } ;
+compose_expression = logical_or_expression , { "&" , logical_or_expression } ;
+
+logical_or_expression  = logical_and_expression , { "||" , logical_and_expression } ;
+logical_and_expression = comparison_expression , { "&&" , comparison_expression } ;
+comparison_expression  = concat_expression , [ comparison_operator , concat_expression ] ;
+concat_expression      = additive_expression , { "++" , additive_expression } ;
+additive_expression    = multiplicative_expression , { ( "+" | "-" ) , multiplicative_expression } ;
+multiplicative_expression = unary_expression , { ( "*" | "/" ) , unary_expression } ;
+
+unary_expression   = [ "!" | "-" ] , postfix_expression ;
+postfix_expression = primary_expression , { call_suffix | path_suffix } ;
+call_suffix        = "(" , [ argument_list ] , ")" ;
+path_suffix        = "." , identifier ;
+
+primary_expression = literal
+                   | identifier
+                   | comparison_constraint
+                   | object
+                   | array_constraint
+                   | array
+                   | let_expression
+                   | function_expression
+                   | match_expression
+                   | import_expression
+                   | "(" , expression , ")" ;
+
+literal            = string | integer | float | "true" | "false" | regex ;
+comparison_operator = "==" | "!=" | "<" | "<=" | ">" | ">=" ;
+comparison_constraint = ( "<" | "<=" | ">" | ">=" ) , expression ;
+
+object             = "{" , [ field_definition , { ";" , field_definition } , [ ";" ] ] , "}" ;
+field_definition   = field_path , "=" , expression ;
+field_path         = identifier , { "." , identifier } ;
+
+array              = "[" , [ expression , { "," , expression } , [ "," ] ] , "]" ;
+array_constraint   = "[" , "..." , expression , [ "," ] , "]" ;
+
+let_expression     = "let" , { field_definition , ";" } , "in" , expression ;
+function_expression = "(" , [ parameter_list ] , ")" , "=>" , expression ;
+parameter_list     = parameter , { "," , parameter } , [ "," ] ;
+parameter          = identifier , [ ":" , expression ] ;
+
+match_expression   = "match" , expression , "{" , [ match_arm , { ";" , match_arm } , [ ";" ] ] , "}" ;
+match_arm          = pattern , ":" , expression ;
+pattern            = "_" | expression ;
+
+import_expression  = "import" , string ;
+argument_list      = expression , { "," , expression } , [ "," ] ;
+```
+
+## Precedence
+
+Precedence is highest first.
+
+1. function call and field path reference
+2. unary `!` and `-`
+3. `*` and `/`
+4. `+` and `-`
+5. `++`
+6. `==`, `!=`, `<`, `<=`, `>`, `>=`
+7. `&&`
+8. `||`
+9. `&`
+10. `//`
+11. `default`
+
+Binary operators are left-associative except `default`, which is right-associative.
+
+## Tooling mapping
+
+Syntax tooling should derive token categories from this grammar rather than making a tool-specific grammar canonical.
+Tree-sitter and Lezer grammars are implementation artifacts that follow this page.
@@ -95,4 +95,5 @@ match value {
 通常の式はエラー内容に基づいて分岐できない。

 汎用 `try / catch` は core には含めない。
-fallback は `default`、`match`、および将来的な optional import / optional field access のような限定された仕組みで表現する。
+fallback は `default` と `match` で表現する。
+optional import や optional field access は core には含めない。
@@ -29,17 +29,80 @@ result = schema;
 ```

 この場合、`result` の右辺の `schema` は同じ module の top-level field `schema` を参照する。
-通常の object literal 内の field を暗黙に recursive scope にするかは別仕様とする。
+通常の object literal 内の field は、その object 内の sibling field を暗黙には識別子として参照できない。
+object 内の値を参照する場合は、外側で束縛された値や明示的な path reference を使う。

-## SourceLoader
+## ImportLoader

-`import` specifier の解決は処理系 core ではなく host 側の `SourceLoader` が行う。
+`import` specifier の解決は処理系 core ではなく host 側の `ImportLoader` が行う。
 CLI では、specifier を現在の module path からの相対 path として解決する。
 組み込み利用では、resource table や static source map など、filesystem 以外の loader を使える。

 module cache の key は loader が返す安定 key を使う。
 CLI では canonical path を key とする。

+### 構造化 import
+
+`ImportLoader::load` は DCDL source または host が構築した `HostValue` を import 結果として返す。
+Markdown、JSON、TOML などの解釈規則は core に固定せず、loader がファイル種別を判定して構造化する。
+
+```rust
+use decodal::{HostValue, ImportLoader, LoadedImport};
+
+struct ContentLoader;
+
+impl ImportLoader for ContentLoader {
+    fn load(
+        &mut self,
+        current_key: Option<&str>,
+        specifier: &str,
+    ) -> decodal::Result<LoadedImport> {
+        if specifier.ends_with(".md") {
+            let markdown = read_content(current_key, specifier)?;
+            let parsed = parse_frontmatter(&markdown)?;
+            return Ok(LoadedImport::value(
+                parsed.key,
+                HostValue::object([
+                    ("frontmatter", parsed.frontmatter),
+                    ("body", HostValue::string(parsed.body)),
+                ]),
+            ));
+        }
+
+        let source = read_dcdl(current_key, specifier)?;
+        Ok(LoadedImport::source(
+            source.key,
+            specifier,
+            source.text,
+        ))
+    }
+}
+```
+
+`read_content` と `parse_frontmatter` は host 独自の処理であり、Decodal core は Markdown や YAML parser に依存しない。
+上の loader を使うと、DCDL 側から次のように扱える。
+
+```dcdl
+Post = {
+    frontmatter = {
+        title = String;
+        draft = Bool default false;
+    };
+    body = String;
+};
+
+post = Post & import "./hello.md";
+title = post.frontmatter.title;
+body = post.body;
+```
+
+`LoadedImport::Value` は通常の concrete runtime value に internalize される。
+そのため、path reference、object composition、constraint validation、materialize は source 由来の値と同じ規則を使う。
+安定した `key` が同じ構造化 import は、engine 内で同じ値としてキャッシュされる。
+
+`load` が唯一の import hook である。
+loader は拡張子、media type、または host 独自の規則で振り分け、対応する `LoadedImport` variant を直接返す。
+
 ## 循環 import

 モジュール間に循環参照があっても、必要なフィールドの依存関係が循環していなければ評価できる。
@@ -92,4 +155,5 @@ Module func
 - ファイルが読めない。
 - import 先の構文解析に失敗する。
 - import 先の評価で必要な値がエラーになる。
+- host による非 DCDL content の読み込みまたは構造化に失敗する。
 - 実装が禁止する import 循環に該当する。
@@ -1,6 +1,79 @@
-# 合成演算子
+# 演算子

-この章では、`&` と `//` の意味を定義する。
+この章では、Decodal の演算子の意味を定義する。
+
+## 演算子一覧
+
+| 演算子 | 形 | 種類 | 対象 | 結果 / 意味 |
+|---|---|---|---|---|
+| `.` | `object.field` | field reference | object / abstract object | field value |
+| call | `fn(arg)` | function call | function | function result |
+| `!` | `!expr` | unary logical | concrete `Bool` | concrete `Bool` |
+| `-` | `-expr` | unary arithmetic | concrete `Int` / `Float` | negated number |
+| `*` | `lhs * rhs` | arithmetic | concrete `Int` / `Float` | numeric product |
+| `/` | `lhs / rhs` | arithmetic | concrete `Int` / `Float` | `Float` quotient |
+| `+` | `lhs + rhs` | arithmetic | concrete `Int` / `Float` | numeric sum |
+| `-` | `lhs - rhs` | arithmetic | concrete `Int` / `Float` | numeric difference |
+| `++` | `lhs ++ rhs` | array concat | concrete arrays | concatenated array |
+| `==` | `lhs == rhs` | equality | concrete scalar | concrete `Bool` |
+| `!=` | `lhs != rhs` | equality | concrete scalar | concrete `Bool` |
+| `<` | `lhs < rhs` | ordering | concrete `Int` / `Float` | concrete `Bool` |
+| `<=` | `lhs <= rhs` | ordering | concrete `Int` / `Float` | concrete `Bool` |
+| `>` | `lhs > rhs` | ordering | concrete `Int` / `Float` | concrete `Bool` |
+| `>=` | `lhs >= rhs` | ordering | concrete `Int` / `Float` | concrete `Bool` |
+| `>` | `> value` | comparison constraint | numeric constraint value | abstract constraint |
+| `>=` | `>= value` | comparison constraint | numeric constraint value | abstract constraint |
+| `<` | `< value` | comparison constraint | numeric constraint value | abstract constraint |
+| `<=` | `<= value` | comparison constraint | numeric constraint value | abstract constraint |
+| `&&` | `lhs && rhs` | logical | concrete `Bool` | short-circuit AND |
+| `||` | `lhs || rhs` | logical | concrete `Bool` | short-circuit OR |
+| `&` | `lhs & rhs` | composition | value / constraint / object | constraint-preserving composition |
+| `//` | `lhs // rhs` | patch | object / value | right-biased structural patch |
+| `default` | `base default fallback` | default | abstract value | materialization fallback |
+
+`concrete scalar` は `String`、`Bool`、`Int`、`Float` を指す。
+
+## 優先順位
+
+優先順位は高い順に以下である。
+
+1. 関数呼び出しとフィールド参照
+2. unary `!` `-`
+3. `*` `/`
+4. `+` `-`
+5. `++`
+6. `==` `!=` `<` `<=` `>` `>=`
+7. `&&`
+8. `||`
+9. `&`
+10. `//`
+11. `default`
+
+同じ優先順位の二項演算子は左結合である。
+`default` は右結合である。
+
+## Arithmetic operators
+
+`+` `-` `*` `/` は具体的な `Int` / `Float` に対する四則演算である。
+詳しくは [Arithmetic Expression](./expression/arithmetic.md) を参照する。
+
+## Array concat operator
+
+`++` は concrete array 同士を連結する演算子である。
+要素は変換されず、左辺の要素の後に右辺の要素が並ぶ。
+
+```dcdl
+["read", "write"] ++ ["admin"]
+```
+
+## Logical and comparison operators
+
+`!` `&&` `||` は concrete `Bool` に対する論理演算である。
+`&&` と `||` は短絡評価される。
+
+`==` `!=` は concrete scalar value を比較する。
+`<` `<=` `>` `>=` は concrete numeric value を比較する。
+詳しくは [Logical and Comparison Expressions](./expression/logical-and-comparison.md) を参照する。

 ## `&`: 制約合成

@@ -110,19 +183,10 @@ Patched = Base // {

 ## object 全体の置換

-`//` が deep patch である場合、object 全体を置き換えたいときの escape hatch が必要になる。
+`//` では object/object は常に deep patch される。
+object field 全体を特別に置き換えるための `replace(...)` 構文や組み込み関数は core には含めない。

-候補として、`replace(...)` を組み込み関数として提供する。
-
-```dcdl
-Replaced = Base // {
-    feature_hoge = replace({
-        enable = false;
-    });
-};
-```
-
-この場合、`feature_hoge` は再帰 patch されず、右辺の object に丸ごと置き換わる。
+object 全体を別構造にしたい場合は、patch 対象より外側で値を作り直す。

 ## `&` と `//` の使い分け

@@ -1,7 +1,7 @@
 # 構文と字句

 この章では、表層構文の方針をまとめる。
-厳密な EBNF は未確定であり、今後このファイルに詳細化する。
+厳密な構文は [Grammar](./grammar.md) の EBNF を参照する。

 ## 言語名と拡張子

@@ -93,9 +93,9 @@ config.feature_hoge.enable
 }
 ```

-## 予約語候補
+## 予約語

-以下は予約語または予約構文として扱う候補である。
+以下は予約語として扱う。

 ```text
 let
@@ -105,22 +105,23 @@ import
 default
 true
 false
-rec
 ```

-`rec` の扱いは未確定である。
-
 ## 演算子

 主要な演算子は以下である。

 ```text
-&       制約合成
-//      patch 合成
-default fallback 指定
-=>      関数
-.       フィールド参照 / ドットパス定義
+ - * /       四則演算
++            配列結合
+! && ||       論理演算
+== != < <= > >= 比較式
+&             制約合成
+//            patch 合成
+default       fallback 指定
+=>            関数
+.             フィールド参照 / ドットパス定義
+...           配列の要素制約
 ```

-演算子の優先順位は未確定である。
-詳細は [合成演算子](./operators.md) で定義する。
+演算子の優先順位は [合成演算子](./operators.md) で定義する。
@@ -9,7 +9,10 @@ ratio = Float;
 threshold = Float default 0.5;
 ```

-## 未確定事項
+## Int との関係

-`Int` と `Float` の暗黙変換を許可するかは未確定である。
-軽量実装では、両者を明確に分ける方が単純である。
+`Int` と `Float` は primitive type constraint としては別の型である。
+`Float` constraint は concrete `Float` を要求し、`Int` constraint は concrete `Int` を要求する。
+
+数値演算や比較式では `Int` と `Float` を同じ numeric value として扱える。
+混在した四則演算の結果は `Float` になる。
@@ -9,9 +9,11 @@ name = String;
 retry = Int default 3;
 ratio = Float;
 enable = Bool default true;
+tags = [...String];
 ```

 現在の primitive type は `String`、`Int`、`Float`、`Bool` である。
+配列は primitive type ではなく、必須の要素制約を持つ `[...T]` で表現する。
 各型の個別仕様へのリンクは [Manual Index](../../index.md) に集約する。

 primitive type と制約合成の詳細は [制約と default](../constraints-and-defaults.md) も参照する。
@@ -17,4 +17,5 @@ greeting = String default "hello";
 message = String & /Hello! .*/;
 ```

-正規表現制約を必須機能にするかは未確定である。
+正規表現制約の検証は Rust crate の `regex` feature で有効化される。
+feature が無効な場合、正規表現制約は具体 string に対して検証できず diagnostic になる。
@@ -1,60 +1,23 @@
 # 未確定事項

 今後決める必要がある事項を管理する。
-詳細化するときは、各項目を該当する仕様ファイルへ移動または反映する。
+実装または仕様方針が固まった項目は、該当する仕様ファイルへ反映してここから外す。

-## 構文
+## Materialize target and host projection

- 正式な字句・構文仕様。
- 演算子の優先順位。
- `rec` の扱い。
- コメント構文を `#` のみにするか。
+Decodal の評価結果は、制約・default・関数値を含む中間値になり得る。
+そのため、Decodal 単独で常に「最終成果物」を一意に決めるのではなく、host 側が期待する型や出力形式を与えて materialize / decode する経路を明確にする必要がある。

-## 型・制約
+決めること:

- 配列要素の制約表現。
- object の open/closed schema の扱い。
- 正規表現を必須機能にするか optional feature にするか。
- 代表的な組み込み述語の範囲。
+- Rust API で評価結果の field/path を選択して decode / materialize できるようにするか。
+- `decodal-derive` の struct schema と評価結果を合成して decode する経路を、主要な materialize path として位置づけるか。
+- CLI / WASM では target path を指定して JSON-compatible value へ materialize する形にするか。
+- 制約や関数値が残った値を出力したい場合、materialize ではなく inspect/debug API として分けるか。

-## default
+現時点の案:

- `default` 同士の conflict 解決規則。
- `&` による default 合成の厳密な規則。
- `//` による default 置換の厳密な規則。
- default thunk の評価失敗をどの段階で報告するか。
-
-## 演算子
-
- `//` による制約・default の置換詳細。
- `replace(...)` を採用するか、別構文を設けるか。
- 配列に対する patch 操作を右辺置換だけにするか。
- 配列 append / prepend / remove などを提供するか。
-
-## 関数
-
- 関数値の最終出力可否。
- 再帰関数を許可するか。
- 関数同士の `&` の扱い。
- 関数値の等価性。
- 関数呼び出し結果の memoize 範囲。
-
-## 評価
-
- thunk のエラー memoize 方針。
- import cache の単位。
- 循環 import の診断メッセージ。
- materialize 対象の範囲指定方法。
-
-## match
-
- match の網羅性チェックを行うか。
- 到達不能分岐を警告するか。
- パターン構文の範囲。
-
-## エラー処理
-
- optional import を導入するか。
- optional field access を導入するか。
- optional fallback が捕捉できる失敗の範囲。
- エラー報告に制約由来の説明をどこまで含めるか。
+- Rust では `evaluate -> select field/path -> expected schema と合成 -> decode` を主経路にする。
+- CLI / WASM では、明示された target path または module 全体を JSON-compatible value として materialize する。
+- materialize できない unresolved abstract value、default のない制約値、関数値は diagnostic にする。
+- Decodal 言語内には materialize 構文を追加せず、host API / CLI / WASM の責務として扱う。
@@ -0,0 +1,18 @@
+# lezer-decodal
+
+Lezer implementation of the Decodal grammar for CodeMirror 6.
+
+The canonical grammar is documented in:
+
+```text
+../../doc/manual/souce/language/grammar.md
+```
+
+Regenerate the CodeMirror parser from the site directory:
+
+```sh
+cd ../../site/decodal-site
+npx lezer-generator ../../editors/lezer-decodal/decodal.grammar -o ../../packages/decodal-codemirror/src/decodal-parser.js
+```
+
+The generated parser is committed with the `decodal-codemirror` package because both the playground and external Web editors consume it.
@@ -0,0 +1,175 @@
+@top Source { Statement* }
+
+Statement {
+  FieldDefinition Semicolon? |
+  Expression Semicolon?
+}
+
+Expression { DefaultExpression }
+
+DefaultExpression {
+  PatchExpression |
+  PatchExpression !default Default DefaultExpression
+}
+
+PatchExpression {
+  ComposeExpression |
+  PatchExpression !patch SlashSlash ComposeExpression
+}
+
+ComposeExpression {
+  LogicalOrExpression |
+  ComposeExpression !compose Amp LogicalOrExpression
+}
+
+LogicalOrExpression {
+  LogicalAndExpression |
+  LogicalOrExpression !or PipePipe LogicalAndExpression
+}
+
+LogicalAndExpression {
+  ComparisonExpression |
+  LogicalAndExpression !and AmpAmp ComparisonExpression
+}
+
+ComparisonExpression {
+  ConcatExpression |
+  ConcatExpression !compare CompareOperator ConcatExpression
+}
+
+ConcatExpression {
+  AdditiveExpression |
+  ConcatExpression !concat PlusPlus AdditiveExpression
+}
+
+AdditiveExpression {
+  MultiplicativeExpression |
+  AdditiveExpression !add (Plus | Minus) MultiplicativeExpression
+}
+
+MultiplicativeExpression {
+  UnaryExpression |
+  MultiplicativeExpression !multiply (Star | Slash) UnaryExpression
+}
+
+UnaryExpression {
+  PostfixExpression |
+  (Bang | Minus) !unary UnaryExpression
+}
+
+PostfixExpression {
+  PrimaryExpression |
+  PostfixExpression !call CallSuffix |
+  PostfixExpression !path Dot Identifier
+}
+
+CallSuffix { LParen ArgumentList? RParen }
+ArgumentList { Expression (Comma Expression)* Comma? }
+
+PrimaryExpression {
+  Literal |
+  Identifier |
+  ComparisonConstraint |
+  Object |
+  ArrayConstraint |
+  Array |
+  LetExpression |
+  FunctionExpression |
+  MatchExpression |
+  ImportExpression |
+  LParen Expression RParen
+}
+
+Literal { String | Integer | Float | True | False | Regex }
+CompareOperator { EqualEqual | BangEqual | Lt | Lte | Gt | Gte }
+ComparisonConstraint { (Lt | Lte | Gt | Gte) Expression }
+
+Object { LBrace (FieldDefinition (Semicolon FieldDefinition)* Semicolon?)? RBrace }
+FieldDefinition { FieldPath Equal Expression }
+FieldPath { Identifier !fieldPath (Dot Identifier)* }
+
+Array { LBracket (Expression (Comma Expression)* Comma?)? RBracket }
+ArrayConstraint { LBracket Ellipsis Expression Comma? RBracket }
+
+LetExpression { Let FieldDefinitionList In Expression }
+FieldDefinitionList { (FieldDefinition Semicolon)* }
+
+FunctionExpression { LParen ParameterList? RParen Arrow Expression }
+ParameterList { Parameter (Comma Parameter)* Comma? }
+Parameter { Identifier Colon Expression }
+
+MatchExpression { Match Expression LBrace (MatchArm (Semicolon MatchArm)* Semicolon?)? RBrace }
+MatchArm { Pattern Colon Expression }
+Pattern { Underscore | Expression }
+
+ImportExpression { Import String }
+
+@precedence {
+  fieldPath @left,
+  default @right,
+  patch @left,
+  compose @left,
+  or @left,
+  and @left,
+  compare @left,
+  concat @left,
+  add @left,
+  multiply @left,
+  unary,
+  call @left,
+  path @left
+}
+
+@tokens {
+  Let { "let" }
+  In { "in" }
+  Match { "match" }
+  Import { "import" }
+  Default { "default" }
+  True { "true" }
+  False { "false" }
+
+  Identifier { $[A-Za-z_] $[A-Za-z0-9_]* }
+  Integer { $[0-9]+ }
+  Float { $[0-9]+ "." $[0-9]+ }
+  String { '"' (!["\\\n] | "\\" _)* '"' }
+  Regex { "/" (![/\\\n] | "\\" _)+ "/" }
+  Comment { "#" ![\n]* }
+
+  LBrace { "{" }
+  RBrace { "}" }
+  LBracket { "[" }
+  RBracket { "]" }
+  LParen { "(" }
+  RParen { ")" }
+  Semicolon { ";" }
+  Comma { "," }
+  Dot { "." }
+  Ellipsis { "..." }
+  Colon { ":" }
+  Equal { "=" }
+  EqualEqual { "==" }
+  Bang { "!" }
+  BangEqual { "!=" }
+  Arrow { "=>" }
+  Amp { "&" }
+  AmpAmp { "&&" }
+  PipePipe { "||" }
+  Plus { "+" }
+  PlusPlus { "++" }
+  Minus { "-" }
+  Star { "*" }
+  Slash { "/" }
+  SlashSlash { "//" }
+  Gt { ">" }
+  Gte { ">=" }
+  Lt { "<" }
+  Lte { "<=" }
+  Underscore { "_" }
+
+  whitespace { @whitespace+ }
+
+  @precedence { Let, In, Match, Import, Default, True, False, Float, Integer, Underscore, Identifier }
+}
+
+@skip { whitespace | Comment }
@@ -6,7 +6,7 @@ license = "MIT"
 readme = "README.md"
 keywords = ["incremental", "parsing", "tree-sitter", "decodal"]
 categories = ["parsing", "text-editors"]
-repository = "https://github.com/tree-sitter/tree-sitter-decodal"
+repository = "https://gitea.hareworks.net/Hare/Decodal"
 edition = "2021"
 autoexamples = false

@@ -17,7 +17,7 @@ include = ["bindings/rust/*", "grammar.js", "queries/*", "src/*"]
 path = "bindings/rust/lib.rs"

 [dependencies]
-tree-sitter = ">=0.22.6"
+tree-sitter = "0.22.6"

 [build-dependencies]
 cc = "1.0.87"
@@ -0,0 +1,12 @@
+# tree-sitter-decodal
+
+Tree-sitter implementation of the Decodal grammar.
+
+The canonical grammar is documented in:
+
+```text
+../../doc/manual/souce/language/grammar.md
+```
+
+This grammar is an editor/tooling implementation of that EBNF reference.
+Generated parser files under `src/` are committed.
@@ -74,3 +74,111 @@ base // {
            body: (literal (string)))
          (match_arm
            body: (literal (string))))))))
+
+==================
+Arithmetic
+==================
+{
+  value = 1 + 2 * 3;
+  grouped = (1 + 2) / -3;
+}
+---
+
+(source_file
+  (object
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (literal (integer))
+        right: (binary_expression
+          left: (literal (integer))
+          right: (literal (integer)))))
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (parenthesized_expression
+          (binary_expression
+            left: (literal (integer))
+            right: (literal (integer))))
+        right: (unary_expression
+          operand: (literal (integer)))))))
+
+==================
+Logical and comparison
+==================
+{
+  enabled = env == "prod" && replicas > 1;
+  disabled = !enabled || false;
+}
+---
+
+(source_file
+  (object
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (binary_expression
+          left: (identifier)
+          right: (literal (string)))
+        right: (binary_expression
+          left: (identifier)
+          right: (literal (integer)))))
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (unary_expression
+          operand: (identifier))
+        right: (literal (boolean))))))
+
+==================
+Array concat
+==================
+{
+  roles = ["read"] ++ ["write", "admin"];
+  ports = [8000 + 80] ++ [9443];
+}
+---
+
+(source_file
+  (object
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (array
+          (literal (string)))
+        right: (array
+          (literal (string))
+          (literal (string)))))
+    (field_definition
+      path: (field_path (identifier))
+      value: (binary_expression
+        left: (array
+          (binary_expression
+            left: (literal (integer))
+            right: (literal (integer))))
+        right: (array
+          (literal (integer)))))))
+
+==================
+Array constraints
+==================
+{
+  tags = [...String];
+  ports = [...(Int & >= 1),];
+}
+---
+
+(source_file
+  (object
+    (field_definition
+      path: (field_path (identifier))
+      value: (array_constraint
+        element: (identifier)))
+    (field_definition
+      path: (field_path (identifier))
+      value: (array_constraint
+        element: (parenthesized_expression
+          (binary_expression
+            left: (identifier)
+            right: (comparison_constraint
+              value: (integer))))))))
@@ -1,9 +1,19 @@
+// Tree-sitter implementation of the canonical EBNF grammar in
+// doc/manual/souce/language/grammar.md.
+
 const PREC = {
  DEFAULT: 1,
  PATCH: 2,
-  AND: 3,
-  CALL: 7,
-  PATH: 8,
+  COMPOSE: 3,
+  OR: 4,
+  LOGICAL_AND: 5,
+  COMPARE: 6,
+  CONCAT: 7,
+  ADD: 8,
+  MUL: 9,
+  UNARY: 10,
+  CALL: 11,
+  PATH: 12,
 };

 function commaSep(rule) {
@@ -44,6 +54,7 @@ module.exports = grammar({
      $.regex_literal,
      $.comparison_constraint,
      $.object,
+      $.array_constraint,
      $.array,
      $.let_expression,
      $.function_expression,
@@ -52,6 +63,7 @@ module.exports = grammar({
      $.parenthesized_expression,
      $.call_expression,
      $.path_expression,
+      $.unary_expression,
      $.binary_expression,
      $.default_expression,
    ),
@@ -105,6 +117,14 @@ module.exports = grammar({
      ']',
    ),

+    array_constraint: $ => seq(
+      '[',
+      '...',
+      field('element', $._expression),
+      optional(','),
+      ']',
+    ),
+
    let_expression: $ => seq(
      'let',
      repeat(seq($.field_definition, ';')),
@@ -159,13 +179,48 @@ module.exports = grammar({
      field('field', $.identifier),
    )),

-    comparison_constraint: $ => prec(6, seq(
+    comparison_constraint: $ => prec.right(PREC.UNARY + 1, seq(
      field('operator', choice('>', '>=', '<', '<=')),
-      field('value', choice($.integer, $.float)),
+      field('value', $._expression),
+    )),
+
+    unary_expression: $ => prec(PREC.UNARY, seq(
+      field('operator', choice('-', '!')),
+      field('operand', $._expression),
    )),

    binary_expression: $ => choice(
-      prec.left(PREC.AND, seq(
+      prec.left(PREC.OR, seq(
+        field('left', $._expression),
+        field('operator', token(prec(2, '||'))),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.LOGICAL_AND, seq(
+        field('left', $._expression),
+        field('operator', token(prec(2, '&&'))),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.COMPARE, seq(
+        field('left', $._expression),
+        field('operator', choice('==', '!=', '>', '>=', '<', '<=')),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.CONCAT, seq(
+        field('left', $._expression),
+        field('operator', token(prec(2, '++'))),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.ADD, seq(
+        field('left', $._expression),
+        field('operator', choice('+', '-')),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.MUL, seq(
+        field('left', $._expression),
+        field('operator', choice('*', '/')),
+        field('right', $._expression),
+      )),
+      prec.left(PREC.COMPOSE, seq(
        field('left', $._expression),
        field('operator', '&'),
        field('right', $._expression),
@@ -17,6 +17,17 @@
 [
  "&"
  "//"
+  "+"
+  "-"
+  "*"
+  "/"
+  "++"
+  "..."
+  "&&"
+  "||"
+  "!"
+  "=="
+  "!="
  "=>"
  "="
  ">"
@@ -95,6 +95,10 @@
          "type": "SYMBOL",
          "name": "object"
        },
+        {
+          "type": "SYMBOL",
+          "name": "array_constraint"
+        },
        {
          "type": "SYMBOL",
          "name": "array"
@@ -127,6 +131,10 @@
          "type": "SYMBOL",
          "name": "path_expression"
        },
+        {
+          "type": "SYMBOL",
+          "name": "unary_expression"
+        },
        {
          "type": "SYMBOL",
          "name": "binary_expression"
@@ -423,6 +431,43 @@
        }
      ]
    },
+    "array_constraint": {
+      "type": "SEQ",
+      "members": [
+        {
+          "type": "STRING",
+          "value": "["
+        },
+        {
+          "type": "STRING",
+          "value": "..."
+        },
+        {
+          "type": "FIELD",
+          "name": "element",
+          "content": {
+            "type": "SYMBOL",
+            "name": "_expression"
+          }
+        },
+        {
+          "type": "CHOICE",
+          "members": [
+            {
+              "type": "STRING",
+              "value": ","
+            },
+            {
+              "type": "BLANK"
+            }
+          ]
+        },
+        {
+          "type": "STRING",
+          "value": "]"
+        }
+      ]
+    },
    "let_expression": {
      "type": "SEQ",
      "members": [
@@ -712,7 +757,7 @@
    },
    "call_expression": {
      "type": "PREC_LEFT",
-      "value": 7,
+      "value": 11,
      "content": {
        "type": "SEQ",
        "members": [
@@ -782,7 +827,7 @@
    },
    "path_expression": {
      "type": "PREC_LEFT",
-      "value": 8,
+      "value": 12,
      "content": {
        "type": "SEQ",
        "members": [
@@ -810,8 +855,8 @@
      }
    },
    "comparison_constraint": {
-      "type": "PREC",
-      "value": 6,
+      "type": "PREC_RIGHT",
+      "value": 11,
      "content": {
        "type": "SEQ",
        "members": [
@@ -843,19 +888,44 @@
          {
            "type": "FIELD",
            "name": "value",
+            "content": {
+              "type": "SYMBOL",
+              "name": "_expression"
+            }
+          }
+        ]
+      }
+    },
+    "unary_expression": {
+      "type": "PREC",
+      "value": 10,
+      "content": {
+        "type": "SEQ",
+        "members": [
+          {
+            "type": "FIELD",
+            "name": "operator",
            "content": {
              "type": "CHOICE",
              "members": [
                {
-                  "type": "SYMBOL",
-                  "name": "integer"
+                  "type": "STRING",
+                  "value": "-"
                },
                {
-                  "type": "SYMBOL",
-                  "name": "float"
+                  "type": "STRING",
+                  "value": "!"
                }
              ]
            }
+          },
+          {
+            "type": "FIELD",
+            "name": "operand",
+            "content": {
+              "type": "SYMBOL",
+              "name": "_expression"
+            }
          }
        ]
      }
@@ -863,6 +933,268 @@
    "binary_expression": {
      "type": "CHOICE",
      "members": [
+        {
+          "type": "PREC_LEFT",
+          "value": 4,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "TOKEN",
+                  "content": {
+                    "type": "PREC",
+                    "value": 2,
+                    "content": {
+                      "type": "STRING",
+                      "value": "||"
+                    }
+                  }
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 5,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "TOKEN",
+                  "content": {
+                    "type": "PREC",
+                    "value": 2,
+                    "content": {
+                      "type": "STRING",
+                      "value": "&&"
+                    }
+                  }
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 6,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "STRING",
+                      "value": "=="
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "!="
+                    },
+                    {
+                      "type": "STRING",
+                      "value": ">"
+                    },
+                    {
+                      "type": "STRING",
+                      "value": ">="
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "<"
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "<="
+                    }
+                  ]
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 7,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "TOKEN",
+                  "content": {
+                    "type": "PREC",
+                    "value": 2,
+                    "content": {
+                      "type": "STRING",
+                      "value": "++"
+                    }
+                  }
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 8,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "STRING",
+                      "value": "+"
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "-"
+                    }
+                  ]
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
+        {
+          "type": "PREC_LEFT",
+          "value": 9,
+          "content": {
+            "type": "SEQ",
+            "members": [
+              {
+                "type": "FIELD",
+                "name": "left",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "operator",
+                "content": {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "STRING",
+                      "value": "*"
+                    },
+                    {
+                      "type": "STRING",
+                      "value": "/"
+                    }
+                  ]
+                }
+              },
+              {
+                "type": "FIELD",
+                "name": "right",
+                "content": {
+                  "type": "SYMBOL",
+                  "name": "_expression"
+                }
+              }
+            ]
+          }
+        },
        {
          "type": "PREC_LEFT",
          "value": 3,
@@ -11,6 +11,10 @@
          "type": "array",
          "named": true
        },
+        {
+          "type": "array_constraint",
+          "named": true
+        },
        {
          "type": "binary_expression",
          "named": true
@@ -66,10 +70,94 @@
        {
          "type": "regex_literal",
          "named": true
+        },
+        {
+          "type": "unary_expression",
+          "named": true
        }
      ]
    }
  },
+  {
+    "type": "array_constraint",
+    "named": true,
+    "fields": {
+      "element": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "array",
+            "named": true
+          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
+          {
+            "type": "binary_expression",
+            "named": true
+          },
+          {
+            "type": "call_expression",
+            "named": true
+          },
+          {
+            "type": "comparison_constraint",
+            "named": true
+          },
+          {
+            "type": "default_expression",
+            "named": true
+          },
+          {
+            "type": "function_expression",
+            "named": true
+          },
+          {
+            "type": "identifier",
+            "named": true
+          },
+          {
+            "type": "import_expression",
+            "named": true
+          },
+          {
+            "type": "let_expression",
+            "named": true
+          },
+          {
+            "type": "literal",
+            "named": true
+          },
+          {
+            "type": "match_expression",
+            "named": true
+          },
+          {
+            "type": "object",
+            "named": true
+          },
+          {
+            "type": "parenthesized_expression",
+            "named": true
+          },
+          {
+            "type": "path_expression",
+            "named": true
+          },
+          {
+            "type": "regex_literal",
+            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
+          }
+        ]
+      }
+    }
+  },
  {
    "type": "binary_expression",
    "named": true,
@@ -82,6 +170,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -137,6 +229,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      },
@@ -144,13 +240,65 @@
        "multiple": false,
        "required": true,
        "types": [
+          {
+            "type": "!=",
+            "named": false
+          },
          {
            "type": "&",
            "named": false
          },
+          {
+            "type": "&&",
+            "named": false
+          },
+          {
+            "type": "*",
+            "named": false
+          },
+          {
+            "type": "+",
+            "named": false
+          },
+          {
+            "type": "++",
+            "named": false
+          },
+          {
+            "type": "-",
+            "named": false
+          },
+          {
+            "type": "/",
+            "named": false
+          },
          {
            "type": "//",
            "named": false
+          },
+          {
+            "type": "<",
+            "named": false
+          },
+          {
+            "type": "<=",
+            "named": false
+          },
+          {
+            "type": "==",
+            "named": false
+          },
+          {
+            "type": ">",
+            "named": false
+          },
+          {
+            "type": ">=",
+            "named": false
+          },
+          {
+            "type": "||",
+            "named": false
          }
        ]
      },
@@ -162,6 +310,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -217,6 +369,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -239,6 +395,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -294,6 +454,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -306,6 +470,10 @@
          "type": "array",
          "named": true
        },
+        {
+          "type": "array_constraint",
+          "named": true
+        },
        {
          "type": "binary_expression",
          "named": true
@@ -361,6 +529,10 @@
        {
          "type": "regex_literal",
          "named": true
+        },
+        {
+          "type": "unary_expression",
+          "named": true
        }
      ]
    }
@@ -396,11 +568,71 @@
        "required": true,
        "types": [
          {
-            "type": "float",
+            "type": "array",
            "named": true
          },
          {
-            "type": "integer",
+            "type": "array_constraint",
+            "named": true
+          },
+          {
+            "type": "binary_expression",
+            "named": true
+          },
+          {
+            "type": "call_expression",
+            "named": true
+          },
+          {
+            "type": "comparison_constraint",
+            "named": true
+          },
+          {
+            "type": "default_expression",
+            "named": true
+          },
+          {
+            "type": "function_expression",
+            "named": true
+          },
+          {
+            "type": "identifier",
+            "named": true
+          },
+          {
+            "type": "import_expression",
+            "named": true
+          },
+          {
+            "type": "let_expression",
+            "named": true
+          },
+          {
+            "type": "literal",
+            "named": true
+          },
+          {
+            "type": "match_expression",
+            "named": true
+          },
+          {
+            "type": "object",
+            "named": true
+          },
+          {
+            "type": "parenthesized_expression",
+            "named": true
+          },
+          {
+            "type": "path_expression",
+            "named": true
+          },
+          {
+            "type": "regex_literal",
+            "named": true
+          },
+          {
+            "type": "unary_expression",
            "named": true
          }
        ]
@@ -419,6 +651,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -474,6 +710,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      },
@@ -485,6 +725,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -540,6 +784,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -567,6 +815,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -622,6 +874,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -654,6 +910,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -709,6 +969,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -752,6 +1016,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -807,6 +1075,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -861,6 +1133,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -916,6 +1192,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      },
@@ -931,6 +1211,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -986,6 +1270,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -1003,6 +1291,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -1058,6 +1350,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -1100,6 +1396,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -1155,6 +1455,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      },
@@ -1182,6 +1486,10 @@
          "type": "array",
          "named": true
        },
+        {
+          "type": "array_constraint",
+          "named": true
+        },
        {
          "type": "binary_expression",
          "named": true
@@ -1237,6 +1545,10 @@
        {
          "type": "regex_literal",
          "named": true
+        },
+        {
+          "type": "unary_expression",
+          "named": true
        }
      ]
    }
@@ -1263,6 +1575,10 @@
            "type": "array",
            "named": true
          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
          {
            "type": "binary_expression",
            "named": true
@@ -1318,6 +1634,10 @@
          {
            "type": "regex_literal",
            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
          }
        ]
      }
@@ -1335,6 +1655,10 @@
          "type": "array",
          "named": true
        },
+        {
+          "type": "array_constraint",
+          "named": true
+        },
        {
          "type": "binary_expression",
          "named": true
@@ -1394,14 +1718,124 @@
        {
          "type": "regex_literal",
          "named": true
+        },
+        {
+          "type": "unary_expression",
+          "named": true
        }
      ]
    }
  },
+  {
+    "type": "unary_expression",
+    "named": true,
+    "fields": {
+      "operand": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "array",
+            "named": true
+          },
+          {
+            "type": "array_constraint",
+            "named": true
+          },
+          {
+            "type": "binary_expression",
+            "named": true
+          },
+          {
+            "type": "call_expression",
+            "named": true
+          },
+          {
+            "type": "comparison_constraint",
+            "named": true
+          },
+          {
+            "type": "default_expression",
+            "named": true
+          },
+          {
+            "type": "function_expression",
+            "named": true
+          },
+          {
+            "type": "identifier",
+            "named": true
+          },
+          {
+            "type": "import_expression",
+            "named": true
+          },
+          {
+            "type": "let_expression",
+            "named": true
+          },
+          {
+            "type": "literal",
+            "named": true
+          },
+          {
+            "type": "match_expression",
+            "named": true
+          },
+          {
+            "type": "object",
+            "named": true
+          },
+          {
+            "type": "parenthesized_expression",
+            "named": true
+          },
+          {
+            "type": "path_expression",
+            "named": true
+          },
+          {
+            "type": "regex_literal",
+            "named": true
+          },
+          {
+            "type": "unary_expression",
+            "named": true
+          }
+        ]
+      },
+      "operator": {
+        "multiple": false,
+        "required": true,
+        "types": [
+          {
+            "type": "!",
+            "named": false
+          },
+          {
+            "type": "-",
+            "named": false
+          }
+        ]
+      }
+    }
+  },
+  {
+    "type": "!",
+    "named": false
+  },
+  {
+    "type": "!=",
+    "named": false
+  },
  {
    "type": "&",
    "named": false
  },
+  {
+    "type": "&&",
+    "named": false
+  },
  {
    "type": "(",
    "named": false
@@ -1410,14 +1844,38 @@
    "type": ")",
    "named": false
  },
+  {
+    "type": "*",
+    "named": false
+  },
+  {
+    "type": "+",
+    "named": false
+  },
+  {
+    "type": "++",
+    "named": false
+  },
  {
    "type": ",",
    "named": false
  },
+  {
+    "type": "-",
+    "named": false
+  },
  {
    "type": ".",
    "named": false
  },
+  {
+    "type": "...",
+    "named": false
+  },
+  {
+    "type": "/",
+    "named": false
+  },
  {
    "type": "//",
    "named": false
@@ -1442,6 +1900,10 @@
    "type": "=",
    "named": false
  },
+  {
+    "type": "==",
+    "named": false
+  },
  {
    "type": "=>",
    "named": false
@@ -1522,6 +1984,10 @@
    "type": "{",
    "named": false
  },
+  {
+    "type": "||",
+    "named": false
+  },
  {
    "type": "}",
    "named": false
@@ -16,7 +16,7 @@ This example exercises multiple current Decodal features together:
 Run it with:

 ```sh
-cargo run -q -p decodal -- examples/advanced/main.dcdl
+cargo run -q -p decodal-cli -- examples/advanced/main.dcdl
 ```

 The entrypoint is `main.dcdl`.
@@ -0,0 +1,7 @@
+{
+  workers = 2 + 2;
+  memory_gib = 1.5 * 4;
+  port = 9000 + 443;
+  timeout_seconds = 30 / 2;
+  negative_offset = -3;
+}
@@ -0,0 +1,6 @@
+{
+  base_roles = ["read", "write"];
+  extra_roles = ["admin"];
+  roles = ["read", "write"] ++ ["admin"];
+  ports = [8000 + 80] ++ [9000 + 443];
+}
@@ -0,0 +1,11 @@
+let
+    Service = {
+        name = String;
+        enabled = Bool default true;
+    };
+    Services = [...Service];
+in
+    Services & [
+        { name = "api"; },
+        { name = "worker"; enabled = false; },
+    ]
@@ -0,0 +1,11 @@
+let
+  env = "prod";
+  replicas = 3;
+in
+{
+  is_prod = env == "prod";
+  scaled = replicas > 1;
+  enabled = env == "prod" && replicas > 1;
+  disabled = !(env == "prod" && replicas > 1);
+  safe = env != "dev" || replicas >= 1;
+}
@@ -3,7 +3,7 @@
 Regex constraints are optional. Run this example with the `regex` feature enabled:

 ```sh
-cargo run -q -p decodal --features regex -- examples/regex/main.dcdl
+cargo run -q -p decodal-cli --features regex -- examples/regex/main.dcdl
 ```

 Without the feature, regex validation returns an unsupported feature diagnostic.
@@ -29,6 +29,7 @@

        apps.default = mkApp "decodal" "Run Decodal";
        apps.decodal = mkApp "decodal" "Run Decodal";
+        apps.decodal-lsp = mkApp "decodal-lsp" "Run the Decodal language server";

        checks.default = decodal;

@@ -24,7 +24,7 @@ let
 in
 rustPlatform.buildRustPackage {
  pname = "decodal";
-  version = "0.1.0";
+  version = "0.1.2";

  src = lib.cleanSourceWith {
    src = srcRoot;
@@ -37,7 +37,9 @@ rustPlatform.buildRustPackage {

  cargoBuildFlags = [
    "-p"
-    "decodal"
+    "decodal-cli"
+    "-p"
+    "decodal-lsp"
  ];

  doInstallCheck = true;
@@ -45,6 +47,7 @@ rustPlatform.buildRustPackage {
    runHook preInstallCheck

    test -x "$out/bin/decodal"
+    test -x "$out/bin/decodal-lsp"
    "$out/bin/decodal" >/dev/null

    runHook postInstallCheck
@@ -0,0 +1,173 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
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+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
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+
+4. Redistribution. You may reproduce and distribute copies of the
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+   meet the following conditions:
+
+   (a) You must give any other recipients of the Work or
+       Derivative Works a copy of this License; and
+
+   (b) You must cause any modified files to carry prominent notices
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+
+   (c) You must retain, in the Source form of any Derivative Works
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+       excluding those notices that do not pertain to any part of
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+
+   (d) If the Work includes a "NOTICE" text file as part of its
+       distribution, then any Derivative Works that You distribute must
+       include a readable copy of the attribution notices contained
+       within such NOTICE file, excluding those notices that do not
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+       of the following places: within a NOTICE text file distributed
+       as part of the Derivative Works; within the Source form or
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+       within a display generated by the Derivative Works, if and
+       wherever such third-party notices normally appear. The contents
+       of the NOTICE file are for informational purposes only and
+       do not modify the License. You may add Your own attribution
+       notices within Derivative Works that You distribute, alongside
+       or as an addendum to the NOTICE text from the Work, provided
+       that such additional attribution notices cannot be construed
+       as modifying the License.
+
+   You may add Your own copyright statement to Your modifications and
+   may provide additional or different license terms and conditions
+   for use, reproduction, or distribution of Your modifications, or
+   for any such Derivative Works as a whole, provided Your use,
+   reproduction, and distribution of the Work otherwise complies with
+   the conditions stated in this License.
+
+5. Submission of Contributions. Unless You explicitly state otherwise,
+   any Contribution intentionally submitted for inclusion in the Work
+   by You to the Licensor shall be under the terms and conditions of
+   this License, without any additional terms or conditions.
+
+6. Trademarks. This License does not grant permission to use the trade
+   names, trademarks, service marks, or product names of the Licensor,
+   except as required for reasonable and customary use in describing the
+   origin of the Work and reproducing the content of the NOTICE file.
+
+7. Disclaimer of Warranty. Unless required by applicable law or
+   agreed to in writing, Licensor provides the Work (and each
+   Contributor provides its Contributions) on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+   implied, including, without limitation, any warranties or conditions
+   of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+   PARTICULAR PURPOSE. You are solely responsible for determining the
+   appropriateness of using or redistributing the Work and assume any
+   risks associated with Your exercise of permissions under this License.
+
+8. Limitation of Liability. In no event and under no legal theory,
+   whether in tort (including negligence), contract, or otherwise,
+   unless required by applicable law (such as deliberate and grossly
+   negligent acts) or agreed to in writing, shall any Contributor be
+   liable to You for damages, including any direct, indirect, special,
+   incidental, or consequential damages of any character arising as a
+   result of this License or out of the use or inability to use the
+   Work (including but not limited to damages for loss of goodwill,
+   work stoppage, computer failure or malfunction, or any and all
+   other commercial damages or losses), even if such Contributor
+   has been advised of the possibility of such damages.
+
+9. Accepting Warranty or Additional Liability. While redistributing
+   the Work or Derivative Works thereof, You may choose to offer,
+   and charge a fee for, acceptance of support, warranty, indemnity,
+   or other liability obligations and/or rights consistent with this
+   License. However, in accepting such obligations, You may act only
+   on Your own behalf and on Your sole responsibility, not on behalf
+   of any other Contributor, and only if You agree to indemnify,
+   defend, and hold each Contributor harmless for any liability
+   incurred by, or claims asserted against, such Contributor by reason
+   of your accepting any such warranty or additional liability.
+
+END OF TERMS AND CONDITIONS
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Decodal contributors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
@@ -0,0 +1,74 @@
+# decodal-codemirror
+
+CodeMirror 6 language support for Decodal.
+
+This package provides the Lezer parser metadata, highlighting tags, indentation rules, block folding, and formatter command used by the Decodal Web playground.
+It does not include the Decodal runtime evaluator.
+Use `decodal-wasm` when you want to evaluate Decodal in a browser.
+
+## Install
+
+```sh
+npm install decodal-codemirror
+```
+
+JSR:
+
+```sh
+deno add jsr:@hare/decodal-codemirror
+```
+
+## Usage
+
+```js
+import { basicSetup } from 'codemirror';
+import { EditorView } from '@codemirror/view';
+import { decodal } from 'decodal-codemirror';
+
+new EditorView({
+  doc: 'Server = { port = Int default 8080; };',
+  extensions: [
+    basicSetup,
+    decodal(),
+  ],
+  parent: document.querySelector('#editor'),
+});
+```
+
+## Exports
+
+```js
+import {
+  decodal,
+  decodalLanguage,
+  decodalHighlightStyle,
+} from 'decodal-codemirror';
+```
+
+`decodal()` accepts a small options object:
+
+```js
+decodal({ highlight: false })
+```
+
+Use this when you want the language support without the bundled highlight style.
+
+## Formatting
+
+The formatter is exposed as a separate subpath so plain syntax highlighting does not force callers to initialize WebAssembly.
+
+```js
+import {
+  formatDecodal,
+  formatDecodalCommand,
+  initDecodalFormatter,
+} from 'decodal-codemirror/format';
+import formatterWasm from 'decodal-codemirror/wasm/decodal_language_tools_bg.wasm?url';
+
+await initDecodalFormatter(formatterWasm);
+
+const result = formatDecodal('Server={port=Int default 8080;};');
+if (result.ok) console.log(result.source);
+
+formatDecodalCommand(view);
+```
@@ -0,0 +1,38 @@
+{
+  "name": "@hare/decodal-codemirror",
+  "version": "0.1.6",
+  "license": "MIT",
+  "exports": {
+    ".": "./src/mod.ts",
+    "./format": "./src/format.ts"
+  },
+  "imports": {
+    "@codemirror/language": "npm:@codemirror/language@^6.12.4",
+    "@codemirror/view": "npm:@codemirror/view@^6.43.6",
+    "@lezer/highlight": "npm:@lezer/highlight@^1.2.3",
+    "@lezer/lr": "npm:@lezer/lr@^1.4.10"
+  },
+  "publish": {
+    "include": [
+      "README.md",
+      "LICENSE-MIT",
+      "LICENSE-APACHE",
+      "src/mod.ts",
+      "src/format.ts",
+      "src/decodal.js",
+      "src/decodal.d.ts",
+      "src/decodal.js.d.ts",
+      "src/format.js",
+      "src/format.d.ts",
+      "src/format.js.d.ts",
+      "src/decodal-parser-jsr.js",
+      "src/decodal-parser.js",
+      "src/decodal-parser.terms.js",
+      "wasm/decodal_language_tools.js",
+      "wasm/decodal_language_tools.d.ts",
+      "wasm/decodal_language_tools_bg.wasm",
+      "wasm/decodal_language_tools_bg.wasm.d.ts",
+      "package.json"
+    ]
+  }
+}
@@ -0,0 +1,119 @@
+{
+  "name": "decodal-codemirror",
+  "version": "0.1.6",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "decodal-codemirror",
+      "version": "0.1.6",
+      "license": "MIT OR Apache-2.0",
+      "devDependencies": {
+        "@codemirror/language": "^6.12.4",
+        "@codemirror/state": "^6.7.1",
+        "@codemirror/view": "^6.43.6",
+        "@lezer/highlight": "^1.2.3",
+        "@lezer/lr": "^1.4.10"
+      },
+      "peerDependencies": {
+        "@codemirror/language": "^6.12.4",
+        "@codemirror/view": "^6.43.6",
+        "@lezer/highlight": "^1.2.3",
+        "@lezer/lr": "^1.4.10"
+      }
+    },
+    "node_modules/@codemirror/language": {
+      "version": "6.12.4",
+      "resolved": "https://registry.npmjs.org/@codemirror/language/-/language-6.12.4.tgz",
+      "integrity": "sha512-1q4PaT+o6PbgpkJt4Q8Fv5XJxTy4FUZ4MWETtyiDw3J0Pyr9E2vqcKL+k9wcvjNTIsauxvE7OfmWj3FRPHQ76A==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.23.0",
+        "@lezer/common": "^1.5.0",
+        "@lezer/highlight": "^1.0.0",
+        "@lezer/lr": "^1.0.0",
+        "style-mod": "^4.0.0"
+      }
+    },
+    "node_modules/@codemirror/state": {
+      "version": "6.7.1",
+      "resolved": "https://registry.npmjs.org/@codemirror/state/-/state-6.7.1.tgz",
+      "integrity": "sha512-9QzNDgE4EYDnAHfrTlR2lwiPciiOymLtwKK+8yHQzCc7GXhAP9xdEbEJFy2IWB1j9UGUl9BsgMmTo/ImA02T7A==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@marijn/find-cluster-break": "^1.0.0"
+      }
+    },
+    "node_modules/@codemirror/view": {
+      "version": "6.43.6",
+      "resolved": "https://registry.npmjs.org/@codemirror/view/-/view-6.43.6.tgz",
+      "integrity": "sha512-EVunGSYN1wz1p75WY1s3Xg7t3i8Yol0kGZGizNdX9BUFgMFILYVe8/u6EVpo7Ff5PwbZuILb4QAq7IZoKzIEQA==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/state": "^6.7.0",
+        "crelt": "^1.0.6",
+        "style-mod": "^4.1.0",
+        "w3c-keyname": "^2.2.4"
+      }
+    },
+    "node_modules/@lezer/common": {
+      "version": "1.5.2",
+      "resolved": "https://registry.npmjs.org/@lezer/common/-/common-1.5.2.tgz",
+      "integrity": "sha512-sxQE460fPZyU3sdc8lafxiPwJHBzZRy/udNFynGQky1SePYBdhkBl1kOagA9uT3pxR8K09bOrmTUqA9wb/PjSQ==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/@lezer/highlight": {
+      "version": "1.2.3",
+      "resolved": "https://registry.npmjs.org/@lezer/highlight/-/highlight-1.2.3.tgz",
+      "integrity": "sha512-qXdH7UqTvGfdVBINrgKhDsVTJTxactNNxLk7+UMwZhU13lMHaOBlJe9Vqp907ya56Y3+ed2tlqzys7jDkTmW0g==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@lezer/common": "^1.3.0"
+      }
+    },
+    "node_modules/@lezer/lr": {
+      "version": "1.4.10",
+      "resolved": "https://registry.npmjs.org/@lezer/lr/-/lr-1.4.10.tgz",
+      "integrity": "sha512-rnCpTIBafOx4mRp43xOxDJbFipJm/c0cia/V5TiGlhmMa+wsSdoGmUN3w5Bqrks/09Q/D4tNAmWaT8p6NRi77A==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@lezer/common": "^1.0.0"
+      }
+    },
+    "node_modules/@marijn/find-cluster-break": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/@marijn/find-cluster-break/-/find-cluster-break-1.0.3.tgz",
+      "integrity": "sha512-FY+MKLBoTsLNJF/eLWaOsXGdz6uh3Iu1axjPf6TUq92IYumcTcXWHoS747JARLkcdlJ/Waiaxc5wQfFO8jC6NA==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/crelt": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/crelt/-/crelt-1.0.7.tgz",
+      "integrity": "sha512-aK6BbWfhf4U/wCcLHKPJl/xa6VkVstRaPywWtMKGwuOLc/wZTyQYuoxgvZnNsBvv7Kg3YTBQYYBCggcviQczuA==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/style-mod": {
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/style-mod/-/style-mod-4.1.3.tgz",
+      "integrity": "sha512-i/n8VsZydrugj3Iuzll8+x/00GH2vnYsk1eomD8QiRrSAeW6ItbCQDtfXCeJHd0iwiNagqjQkvpvREEPtW3IoQ==",
+      "dev": true,
+      "license": "MIT"
+    },
+    "node_modules/w3c-keyname": {
+      "version": "2.2.8",
+      "resolved": "https://registry.npmjs.org/w3c-keyname/-/w3c-keyname-2.2.8.tgz",
+      "integrity": "sha512-dpojBhNsCNN7T82Tm7k26A6G9ML3NkhDsnw9n/eoxSRlVBB4CEtIQ/KTCLI2Fwf3ataSXRhYFkQi3SlnFwPvPQ==",
+      "dev": true,
+      "license": "MIT"
+    }
+  }
+}
@@ -0,0 +1,57 @@
+{
+  "name": "decodal-codemirror",
+  "version": "0.1.6",
+  "description": "CodeMirror 6 language support for Decodal.",
+  "type": "module",
+  "license": "MIT OR Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "git+https://gitea.hareworks.net/Hare/Decodal.git",
+    "directory": "packages/decodal-codemirror"
+  },
+  "scripts": {
+    "test": "node --test src/*.test.mjs"
+  },
+  "exports": {
+    ".": {
+      "types": "./src/decodal.d.ts",
+      "import": "./src/decodal.js"
+    },
+    "./format": {
+      "types": "./src/format.d.ts",
+      "import": "./src/format.js"
+    },
+    "./parser": "./src/decodal-parser.js",
+    "./terms": "./src/decodal-parser.terms.js",
+    "./wasm/decodal_language_tools_bg.wasm": "./wasm/decodal_language_tools_bg.wasm"
+  },
+  "types": "./src/decodal.d.ts",
+  "files": [
+    "README.md",
+    "LICENSE-MIT",
+    "LICENSE-APACHE",
+    "src/",
+    "wasm/decodal_language_tools.js",
+    "wasm/decodal_language_tools.d.ts",
+    "wasm/decodal_language_tools_bg.wasm",
+    "wasm/decodal_language_tools_bg.wasm.d.ts"
+  ],
+  "keywords": [
+    "decodal",
+    "codemirror",
+    "lezer"
+  ],
+  "peerDependencies": {
+    "@codemirror/language": "^6.12.4",
+    "@codemirror/view": "^6.43.6",
+    "@lezer/highlight": "^1.2.3",
+    "@lezer/lr": "^1.4.10"
+  },
+  "devDependencies": {
+    "@codemirror/language": "^6.12.4",
+    "@codemirror/state": "^6.7.1",
+    "@codemirror/view": "^6.43.6",
+    "@lezer/highlight": "^1.2.3",
+    "@lezer/lr": "^1.4.10"
+  }
+}
@@ -0,0 +1,16 @@
+// This file was generated by lezer-generator. You probably shouldn't edit it.
+import {LRParser} from "npm:@lezer/lr@^1.4.10"
+export const parser = LRParser.deserialize({
+  version: 14,
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+  tokenizers: [0, 1],
+  topRules: {"Source":[0,2]},
+  tokenPrec: 2497
+})
@@ -0,0 +1,16 @@
+// This file was generated by lezer-generator. You probably shouldn't edit it.
+import {LRParser} from "@lezer/lr"
+export const parser = LRParser.deserialize({
+  version: 14,
+  states: "8fQYQPOOO#nQPO'#CaOOQO'#Cr'#CrO$wQPO'#CyO&UQPO'#DOO&^QQO'#DXO&hQPO'#DYO&pQPO'#CqO$wQPO'#DeO&zQPO'#DjOOQO'#Cq'#CqOOQO'#Cp'#CpO'PQPO'#CoO$wQPO'#CoOOQO'#Cn'#CnO)iQPO'#CmO.[QPO'#ClO0`QPO'#CkOOQO'#Cj'#CjO2WQPO'#CiO3{QPO'#ChO5mQPO'#CgO7XQPO'#CfOOQO'#Ce'#CeO7cQPO'#C`O7hQPO'#C_OOQO'#D|'#D|QYQPOOO8{QPO'#D}O9QQPO,58{OOQO,59e,59eO9YQPO'#CaOOQO,59j,59jO9bQPO,59jO$wQPO,59nOOQO,59s,59sO9jQPO,59sO9rQPO'#EQO9wQPO'#D[O:PQPO,59tO:UQPO'#CqO:cQPO'#D`O:kQQO,59xO:pQPO,59xO:uQPO,59]O:zQPO,5:POOQO,5:U,5:UO;PQPO'#DlOOQO,59[,59[O;WQPO,59[OOQO,59Z,59ZO$wQPO,59YO$wQPO,59XO$wQPO,59WOOQO'#Dt'#DtO$wQPO,59VO$wQPO,59UO$wQPO,59TO$wQPO,59SO$wQPO,59RO$wQPO,59QO$wQPO,58zOOQO,58y,58yOOQO-E7z-E7zOOQO,5:i,5:iOOQO-E7{-E7{O;]QPO1G/UO;eQPO1G/UOOQO1G/U1G/UO;mQPO1G/YO;uQPO1G/_O;|QPO1G/_OOQO1G/_1G/_OOQO,5:l,5:lOOQO-E8O-E8OO$wQPO1G/`O$wQPO,59{O<UQPO,59zO<^QPO,59zO$wQPO1G/dO<fQQO1G/dOOQO1G.w1G.wO<kQPO1G/kO<uQPO'#DmOOQO,5:W,5:WO<}QPO,5:WOOQO1G.v1G.vOOQO1G.t1G.tO=SQPO1G.sO@jQPO1G.rOBUQPO1G.qOOQO1G.p1G.pOC|QPO1G.oOEqQPO1G.nOGTQPO1G.mOOQO1G.l1G.lOOQO1G.f1G.fOOQO1G.s1G.sOOQO1G.r1G.rOOQO1G.q1G.qOOQO1G.o1G.oOOQO1G.n1G.nOOQO1G.m1G.mOOQO,5:j,5:jOOQO7+$p7+$pOHqQPO7+$pOOQO-E7|-E7|OOQO7+$t7+$tOHyQPO7+$tOOQO,5:k,5:kOOQO7+$y7+$yOIOQPO7+$yOOQO-E7}-E7}OOQO7+$z7+$zOOQO1G/g1G/gOIVQPO'#DaOOQO,5:m,5:mOI[QPO1G/fOOQO-E8P-E8POOQO7+%O7+%OO$wQPO7+%OOOQO'#Dh'#DhOIdQPO'#DgOOQO7+%V7+%VOIiQPO7+%VOIqQPO,5:XOIxQPO,5:XOOQO1G/r1G/rOOQO<<H[<<H[PJQQPO'#EOOOQO<<H`<<H`OOQO<<He<<HeP$wQPO'#EPPJVQPO'#EROOQO<<Hj<<HjO$wQPO,5:ROJ[QPO<<HqOJfQPO<<HqOOQO<<Hq<<HqOJnQPO1G/sOOQO1G/m1G/mOOQO,5:n,5:nOOQOAN>]AN>]OJuQPOAN>]OOQO-E8Q-E8QOOQOG23wG23wP<nQPO'#ESO$wQPO,59XO$wQPO,59WO$wQPO,59VO$wQPO,59TO$wQPO,59SO$wQPO,59ROKPQPO1G.rOKgQPO'#ClOKzQPO'#CkOLnQPO'#ChOMnQPO'#CgONqQPO'#CfO$wQPO,59WO$wQPO,59UO$wQPO,59QO! zQPO1G.qO!!bQPO'#CkO!#oQPO'#CiO$wQPO,59VO$wQPO,59UO$wQPO,59TO$wQPO,59SO$wQPO,59RO$wQPO,59QO$wQPO,58zO!$lQPO1G.oO!%SQPO1G.nO!%jQPO1G.mO!&[QPO'#CiO!'SQPO'#ChO!'wQPO'#CgO!(iQPO'#CfO!)WQPO'#C`",
+  stateData: "!)j~O!yOSPOS~OUPOgQOhQOiQOjQOkQOlQOnROoROpROqROsSOwTO}UO!RVO!YWO!_XO!b]O!c]O~OneXoeXpeXqeX!ReX!ceX!deX!eeX!feX!geX!ieX!jeX!keX!leX!meX!neX!oeX~OVlOUeXWTXgeXheXieXjeXkeXleXseXteXweX}eX!YeX!_eX!beX!weX~P!gOUYOgQOhQOiQOjQOkQOlQOnROoROpROqROsSOwTO}UO!RVO!YWO!_XO!b]O!c]O~OUoOupO~OxrOzsO~P$wOUoO!P!OP~OUxO!VzO~P]Og!OO~OV!RO!R!POUcXgcXhcXicXjcXkcXlcXncXocXpcXqcXscXtcXwcX}cX!YcX!_cX!bcX!ccX!dcX!ecX!fcX!gcX!icX!jcX!kcX!lcX!mcX!ncX!ocX!wcXycXzcX!VcXucX!UcX~O!d!TO!e!TOUaXgaXhaXiaXjaXkaXlaXnaXoaXpaXqaXsaXtaXwaX}aX!RaX!YaX!_aX!baX!caX!faX!gaX!iaX!jaX!kaX!laX!maX!naX!oaX!waXVaXyaXzaX!VaXuaX!UaX~OU`Xg`Xh`Xi`Xj`Xk`Xl`Xn`Xo`Xp`Xq`Xs`Xt`Xw`X}`X!R`X!Y`X!_`X!b`X!g`X!i`X!j`X!k`X!l`X!m`X!n`X!o`X!w`Xy`Xz`X!V`Xu`X!U`X~O!c!UO!f!UO~P,ROn!WOo!WOp!WOq!WO!i!WO!j!WOU_Xg_Xh_Xi_Xj_Xk_Xl_Xs_Xt_Xw_X}_X!R_X!Y_X!__X!b_X!c_X!k_X!l_X!m_X!n_X!o_X!w_X~O!g!VO~P.fOU]Xg]Xh]Xi]Xj]Xk]Xl]Xn]Xo]Xp]Xq]Xs]Xt]Xw]X}]X!R]X!Y]X!_]X!b]X!c]X!l]X!m]X!n]X!o]X!w]X~O!k!YO~P0gOU[Xg[Xh[Xi[Xj[Xk[Xl[Xn[Xo[Xp[Xq[Xs[Xt[Xw[X}[X!R[X!Y[X!_[X!b[X!c[X!m[X!n[X!o[X!w[X~O!l!ZO~P2_OUZXgZXhZXiZXjZXkZXlZXnZXoZXpZXqZXsZXtZXwZX}ZX!RZX!YZX!_ZX!bZX!cZX!nZX!oZX!wZX~O!m![O~P4SOUYXgYXhYXiYXjYXkYXlYXnYXoYXpYXqYXsYXtYXwYX}YX!RYX!YYX!_YX!bYX!cYX!wYX~O!n!]O!o!^O~P5tOW!_O~Ot!`OURXgRXhRXiRXjRXkRXlRXnRXoRXpRXqRXsRXwRX}RX!RRX!YRX!_RX!bRX!cRX!wRX~OU!bO~OVlOWTa~OVlOWTX~Ot!dOu!fO~Oy!hOz!jO~Ot!kO~OUoO!P!OX~O!P!mO~O!U!nOVeX!VeX~P!gOy!oO!V!SX~O!W!qO~O!V!rO~O!V!sO~Os!tO~O!V!vO~P$wOU!xO~OUoOu#[O~Ot#]Ou#[O~Oy#`Oz#_O~Oz#bO~P$wOy#cOz#bO~OU#gO!V!Sa~Oy#iO!V!Sa~O!W#lO~Ou#oO!]#mO~P$wOy#qO!V!aX~O!V#sO~O!d!TO!e!TOUaigaihaiiaijaikailainaioaipaiqaisaitaiwai}ai!Rai!Yai!_ai!bai!cai!fai!gai!iai!jai!kai!lai!mai!nai!oai!waiyaizai!Vaiuai!Uai~O!f!UOn`io`ip`iq`is`it`i!g`i!i`i!j`i!k`i!l`i!m`i!n`i!o`i~OU`ig`ih`ii`ij`ik`il`iw`i}`i!R`i!Y`i!_`i!b`i!c`i!w`i~P?iOs_it_i!k_i!l_i!m_i!n_i!o_i~O!g!VOU_ig_ih_ii_ij_ik_il_in_io_ip_iq_iw_i}_i!R_i!Y_i!__i!b_i!c_i!w_i~PAmOs]it]i!l]i!m]i!n]i!o]i~O!k!YOU]ig]ih]ii]ij]ik]il]in]io]ip]iq]iw]i}]i!R]i!Y]i!_]i!b]i!c]i!w]i~PChOs[it[i!m[i!n[i!o[i~O!l!ZOU[ig[ih[ii[ij[ik[il[in[io[ip[iq[iw[i}[i!R[i!Y[i!_[i!b[i!c[i!w[i~PE`O!m![OUZigZihZiiZijZikZilZinZioZipZiqZisZitZiwZi}Zi!RZi!YZi!_Zi!bZi!cZi!nZi!oZi!wZi~OUoOu#tO~Oz#vO~Oz#wO~P$wO!U!nO~OU#gO!V!Si~O!U#{O~Ot#|Ou$OO~O!V!aa~P$wOy$PO!V!aa~OUoO~OU#gO~Ou$SO!]#mO~P$wOt$TOu$SO~O!V!ai~P$wOu$VO!]#mO~P$wO!c!UOy`iz`i!V`iu`i!U`i~P?iO!c$XO!f$XOV`X!d`X!e`X~P,RO!g$YOV_X!d_X!e_X!f_Xy_Xz_X!V_Xu_X!U_X~P.fO!l$[OV[X!d[X!e[X!f[X!g[X!i[X!j[X!k[Xy[Xz[X!V[Xu[X!U[X~P2_O!m$]OVZX!dZX!eZX!fZX!gZX!iZX!jZX!kZX!lZXyZXzZX!VZXuZX!UZX~P4SO!n$^O!o$gOVYX!dYX!eYX!fYX!gYX!iYX!jYX!kYX!lYX!mYXyYXzYX!VYXuYX!UYX~P5tO!g$eOy_iz_i!V_iu_i!U_i~PAmOn!WOo!WOp!WOq!WO!g$eO!i!WO!j!WOy_Xz_X!k_X!l_X!m_X!n_X!o_X!V_Xs_Xt_Xu_X!U_X~O!k$fOV]X!d]X!e]X!f]X!g]X!i]X!j]Xy]Xz]X!V]Xu]X!U]X~P0gO!k$lOy]iz]i!V]iu]i!U]i~PChO!l$mOy[iz[i!V[iu[i!U[i~PE`O!m$nOyZizZi!nZi!oZi!VZisZitZiuZi!UZi~O!k$lOy]Xz]X!l]X!m]X!n]X!o]X!V]Xs]Xt]Xu]X!U]X~O!l$mOy[Xz[X!m[X!n[X!o[X!V[Xs[Xt[Xu[X!U[X~O!m$nOyZXzZX!nZX!oZX!VZXsZXtZXuZX!UZX~O!n$oO!o$pOyYXzYX!VYXsYXtYXuYX!UYX~OW$qO~O}!P!Y!_!ojkih!]Uj~",
+  goto: "4O!wPPP!x!|#^PPP#j$r%c&U'Q(P)R*O+W,a-h.q/v0{PPPPPP0{PPPP0{PPP0{PPPP0{0{P2QP0{P2T2WPPP0{P2`2hP0{P2n2qPPPPPP2tPPPPPPP2}3T3[3b3l3r3xTjOkSiOkQqSSuUvV#Z!d#]#uShOk]$ySUv!d#]#uSiOkQnRQtTQ|VQ}WQ!grQ!u!PS#S!_$qY#a!h#c#q#x$PQ#e!mQ#f!nQ#k!qW#m!t#|$T$WQ#z#lR$Q#{!QgORTVWkr!P!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$qV#R!^$g$pWfOk!^!_Y$dR!m!q#l$gu$xTVWr!P!h!n!t#c#q#x#{#|$P$T$W$p$qWeOk!^!_Q#Q!]Q#Y$^Y$cR!m!q#l$gQ$t$ou$wTVWr!P!h!n!t#c#q#x#{#|$P$T$W$p$qYdOk!]!^!_Q#P![Q#X$][$bR!m!q#l$^$gQ$s$nw$vTVWr!P!h!n!t#c#q#x#{#|$P$T$W$o$p$q[cOk![!]!^!_Q#O!ZQ#W$[^$jR!m!q#l$]$^$gQ$r$my$uTVWr!P!h!n!t#c#q#x#{#|$P$T$W$n$o$p$q!jbORTVWkr!P!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$[$]$^$g$m$n$o$p$qV!}!Y$f$l`aOk!Y!Z![!]!^!_Q!|!XQ#V$Zb$aR!m!q#l$[$]$^$f$gQ$h$k}$iTVWr!P!h!n!t#c#q#x#{#|$P$T$W$l$m$n$o$p$q!b`OTVWkr!P!X!Y!Z![!]!^!_!h!n!t#c#q#x#{#|$P$T$W$k$l$m$n$o$p$qQ!{!VQ#U$YQ$_$ee$`R!m!q#l$Z$[$]$^$f$g!|_ORTVWkr!P!V!X!Y!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$Y$Z$[$]$^$e$f$g$k$l$m$n$o$p$qQ!z!UR#T$X#Q^ORTVWkr!P!U!V!X!Y!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$X$Y$Z$[$]$^$e$f$g$k$l$m$n$o$p$qQ!S]R!y!T#V[ORTVW]kr!P!T!U!V!X!Y!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$X$Y$Z$[$]$^$e$f$g$k$l$m$n$o$p$q#VZORTVW]kr!P!T!U!V!X!Y!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$X$Y$Z$[$]$^$e$f$g$k$l$m$n$o$p$q#VYORTVW]kr!P!T!U!V!X!Y!Z![!]!^!_!h!m!n!q!t#c#l#q#x#{#|$P$T$W$X$Y$Z$[$]$^$e$f$g$k$l$m$n$o$p$qRwUR{VQyVV#h!o#i#yQ#p!tV$R#|$T$WX#n!t#|$T$WR!Q[R!w!PQ!XaQ$Z$aR$k$iQkOR!akSmPoR!cmQ!eqR#^!eQ!itS#d!i#rR#r!uQvUR!lvQ!pyR#j!pQ#}#pR$U#}",
+  nodeNames: "⚠ Comment Source Statement FieldDefinition FieldPath Identifier Dot Equal Expression DefaultExpression PatchExpression ComposeExpression LogicalOrExpression LogicalAndExpression ComparisonExpression ConcatExpression AdditiveExpression MultiplicativeExpression UnaryExpression PostfixExpression PrimaryExpression Literal String Integer Float True False Regex ComparisonConstraint Lt Lte Gt Gte Object LBrace Semicolon RBrace ArrayConstraint LBracket Ellipsis Comma RBracket Array LetExpression Let FieldDefinitionList In FunctionExpression LParen ParameterList Parameter Colon RParen Arrow MatchExpression Match MatchArm Pattern Underscore ImportExpression Import CallSuffix ArgumentList Bang Minus Star Slash Plus PlusPlus CompareOperator EqualEqual BangEqual AmpAmp PipePipe Amp SlashSlash Default",
+  maxTerm: 87,
+  skippedNodes: [0,1],
+  repeatNodeCount: 7,
+  tokenData: "=c~R!PX^$Upq$Uqr$yrs%Wst&zvw'cxy'pyz'uz{'z{|(P|}(^}!O(c!O!P(h!P!Q({!Q![+c![!]+|!]!^,R!^!_,W!_!`,e!`!a,z!c!}-X!}#O-j#P#Q-o#R#S-t#T#W-X#W#X.X#X#Y-X#Y#Z1i#Z#]-X#]#^3y#^#`-X#`#a7]#a#b8p#b#h-X#h#i;Q#i#o-X#o#p<|#p#q=R#q#r=^#y#z$U$f$g$U#BY#BZ$U$IS$I_$U$I|$JO$U$JT$JU$U$KV$KW$U&FU&FV$U~$ZY!y~X^$Upq$U#y#z$U$f$g$U#BY#BZ$U$IS$I_$U$I|$JO$U$JT$JU$U$KV$KW$U&FU&FV$U~%OP!b~!_!`%R~%WO!j~~%ZWOY%WZr%Wrs%ss#O%W#O#P%x#P;'S%W;'S;=`&t<%lO%W~%xOg~~%{RO;'S%W;'S;=`&U;=`O%W~&XXOY%WZr%Wrs%ss#O%W#O#P%x#P;'S%W;'S;=`&t;=`<%l%W<%lO%W~&wP;=`<%l%W~'PSP~OY&zZ;'S&z;'S;=`']<%lO&z~'`P;=`<%l&z~'hP!m~vw'k~'pO!k~~'uO!R~~'zO!V~~(PO!d~~(UP!f~{|(X~(^O!g~~(cOy~~(hO!c~R(mPVP!O!P(pQ(sP!O!P(vQ({OxQ~)QW!e~OY)jZ!P)j!P!Q+^!Q#O)j#O#P*[#P;'S)j;'S;=`+W<%lO)j~)mWOY)jZ!P)j!P!Q*V!Q#O)j#O#P*[#P;'S)j;'S;=`+W<%lO)j~*[Ol~~*_RO;'S)j;'S;=`*h;=`O)j~*kXOY)jZ!P)j!P!Q*V!Q#O)j#O#P*[#P;'S)j;'S;=`+W;=`<%l)j<%lO)j~+ZP;=`<%l)j~+cO!n~~+hQh~!O!P+n!Q![+c~+qP!Q![+t~+yPi~!Q![+t~,RO!U~~,WOt~~,]Pn~!_!`,`~,eOo~~,jQWP!_!`,p!`!a,u~,uO!i~Q,zO!WQ~-PPp~!_!`-S~-XOq~~-^SU~!Q![-X!c!}-X#R#S-X#T#o-X~-oOw~~-tOz~~-{S!]~U~!Q![-X!c!}-X#R#S-X#T#o-X~.^UU~!Q![-X!c!}-X#R#S-X#T#X-X#X#Y.p#Y#o-X~.uUU~!Q![-X!c!}-X#R#S-X#T#Y-X#Y#Z/X#Z#o-X~/^TU~!Q![-X!c!}-X#R#S-X#T#U/m#U#o-X~/rUU~!Q![-X!c!}-X#R#S-X#T#i-X#i#j0U#j#o-X~0ZUU~!Q![-X!c!}-X#R#S-X#T#`-X#`#a0m#a#o-X~0rUU~!Q![-X!c!}-X#R#S-X#T#h-X#h#i1U#i#o-X~1]S!o~U~!Q![-X!c!}-X#R#S-X#T#o-X~1nTU~!Q![-X!c!}-X#R#S-X#T#U1}#U#o-X~2SUU~!Q![-X!c!}-X#R#S-X#T#`-X#`#a2f#a#o-X~2kUU~!Q![-X!c!}-X#R#S-X#T#g-X#g#h2}#h#o-X~3SUU~!Q![-X!c!}-X#R#S-X#T#X-X#X#Y3f#Y#o-X~3mSk~U~!Q![-X!c!}-X#R#S-X#T#o-X~4OVU~!Q![-X!c!}-X#R#S-X#T#a-X#a#b4e#b#c6x#c#o-X~4jUU~!Q![-X!c!}-X#R#S-X#T#d-X#d#e4|#e#o-X~5RUU~!Q![-X!c!}-X#R#S-X#T#c-X#c#d5e#d#o-X~5jUU~!Q![-X!c!}-X#R#S-X#T#f-X#f#g5|#g#o-X~6RUU~!Q![-X!c!}-X#R#S-X#T#h-X#h#i6e#i#o-X~6lS!_~U~!Q![-X!c!}-X#R#S-X#T#o-X~7PS!P~U~!Q![-X!c!}-X#R#S-X#T#o-X~7bUU~!Q![-X!c!}-X#R#S-X#T#X-X#X#Y7t#Y#o-X~7yUU~!Q![-X!c!}-X#R#S-X#T#h-X#h#i8]#i#o-X~8dS}~U~!Q![-X!c!}-X#R#S-X#T#o-X~8uTU~!Q![-X!c!}-X#R#S-X#T#U9U#U#o-X~9ZUU~!Q![-X!c!}-X#R#S-X#T#h-X#h#i9m#i#o-X~9rUU~!Q![-X!c!}-X#R#S-X#T#V-X#V#W:U#W#o-X~:ZUU~!Q![-X!c!}-X#R#S-X#T#[-X#[#]:m#]#o-X~:tS!Y~U~!Q![-X!c!}-X#R#S-X#T#o-X~;VUU~!Q![-X!c!}-X#R#S-X#T#f-X#f#g;i#g#o-X~;nUU~!Q![-X!c!}-X#R#S-X#T#i-X#i#j<Q#j#o-X~<VUU~!Q![-X!c!}-X#R#S-X#T#X-X#X#Y<i#Y#o-X~<pSj~U~!Q![-X!c!}-X#R#S-X#T#o-X~=ROs~~=UP#p#q=X~=^O!l~~=cOu~",
+  tokenizers: [0, 1],
+  topRules: {"Source":[0,2]},
+  tokenPrec: 2497
+})
@@ -0,0 +1,79 @@
+// This file was generated by lezer-generator. You probably shouldn't edit it.
+export const
+  Comment = 1,
+  Source = 2,
+  Statement = 3,
+  FieldDefinition = 4,
+  FieldPath = 5,
+  Identifier = 6,
+  Dot = 7,
+  Equal = 8,
+  Expression = 9,
+  DefaultExpression = 10,
+  PatchExpression = 11,
+  ComposeExpression = 12,
+  LogicalOrExpression = 13,
+  LogicalAndExpression = 14,
+  ComparisonExpression = 15,
+  ConcatExpression = 16,
+  AdditiveExpression = 17,
+  MultiplicativeExpression = 18,
+  UnaryExpression = 19,
+  PostfixExpression = 20,
+  PrimaryExpression = 21,
+  Literal = 22,
+  String = 23,
+  Integer = 24,
+  Float = 25,
+  True = 26,
+  False = 27,
+  Regex = 28,
+  ComparisonConstraint = 29,
+  Lt = 30,
+  Lte = 31,
+  Gt = 32,
+  Gte = 33,
+  Object = 34,
+  LBrace = 35,
+  Semicolon = 36,
+  RBrace = 37,
+  ArrayConstraint = 38,
+  LBracket = 39,
+  Ellipsis = 40,
+  Comma = 41,
+  RBracket = 42,
+  Array = 43,
+  LetExpression = 44,
+  Let = 45,
+  FieldDefinitionList = 46,
+  In = 47,
+  FunctionExpression = 48,
+  LParen = 49,
+  ParameterList = 50,
+  Parameter = 51,
+  Colon = 52,
+  RParen = 53,
+  Arrow = 54,
+  MatchExpression = 55,
+  Match = 56,
+  MatchArm = 57,
+  Pattern = 58,
+  Underscore = 59,
+  ImportExpression = 60,
+  Import = 61,
+  CallSuffix = 62,
+  ArgumentList = 63,
+  Bang = 64,
+  Minus = 65,
+  Star = 66,
+  Slash = 67,
+  Plus = 68,
+  PlusPlus = 69,
+  CompareOperator = 70,
+  EqualEqual = 71,
+  BangEqual = 72,
+  AmpAmp = 73,
+  PipePipe = 74,
+  Amp = 75,
+  SlashSlash = 76,
+  Default = 77
@@ -0,0 +1,11 @@
+import { HighlightStyle } from '@codemirror/language';
+import { LRLanguage, LanguageSupport } from '@codemirror/language';
+
+export declare const decodalLanguage: LRLanguage;
+export declare const decodalHighlightStyle: HighlightStyle;
+
+export interface DecodalOptions {
+  highlight?: boolean;
+}
+
+export declare function decodal(options?: DecodalOptions): LanguageSupport;
--- a/Show More
+++ b/Show More
Author	SHA1	Message	Date
Hare	8198b615a8	Clarify site build and deploy scripts	2026-08-13 19:53:38 +09:00
Hare	62aa81b91c	Fix JSR license metadata	2026-08-13 19:45:04 +09:00
Hare	9c46635ee0	Bump Rust crates for breaking release	2026-08-13 19:40:08 +09:00
Hare	515adc2533	Unify formatting on canonical syntax	2026-08-13 19:31:21 +09:00
Hare	d9cf24d0eb	Prepare Decodal packages for release	2026-08-13 19:01:14 +09:00
Hare	d28edcf041	Share host-aware completion across runtimes	2026-08-13 18:55:03 +09:00
Hare	e862e53f3e	Add project-aware playground completion	2026-08-13 18:07:24 +09:00
Hare	610358110f	Add host-configurable LSP server	2026-08-12 05:42:45 +09:00
Hare	bdaccd9803	Add host-configurable language service	2026-08-11 22:05:17 +09:00
Hare	08603dc4b5	Report structured import origins in diagnostics	2026-08-11 19:20:11 +09:00
Hare	165daada23	Add host-structured imports	2026-08-11 18:33:49 +09:00
Hare	46b2b3b1b6	Add required array element constraints	2026-08-11 17:24:04 +09:00
Hare	5a05da6fe4	Use non-underscore Astro asset directory	2026-07-10 04:36:22 +09:00
Hare	aa0f464320	Bump CodeMirror package to 0.1.5	2026-07-10 04:30:38 +09:00
Hare	fc1f3e0b25	Improve JSR package metadata	2026-07-10 04:19:00 +09:00
Hare	8eac5c5cb4	Bundle language tools with CodeMirror package	2026-07-09 21:25:04 +09:00
Hare	59cb8f31e4	Simplify package link labels	2026-07-09 20:50:09 +09:00
Hare	4eee2cd2c9	Make package links flex layout	2026-07-09 20:45:16 +09:00
Hare	44b6041e60	Compact package links on landing page	2026-07-09 20:36:57 +09:00
Hare	a95afe0463	Align playground control heights	2026-07-09 19:36:15 +09:00
Hare	43ab6244ef	Reduce button vertical padding	2026-07-09 19:34:33 +09:00
Hare	1d4503b015	Simplify playground action separator	2026-07-09 19:33:48 +09:00
Hare	250e29e00c	Remove playground helper copy	2026-07-09 19:29:22 +09:00
Hare	1080081cec	Reset state before loading playground examples	2026-07-09 19:27:19 +09:00
Hare	43f692e75c	Add playground entry selector	2026-07-09 19:21:12 +09:00
Hare	5b26d071ca	Run playground examples from entrypoint	2026-07-09 19:12:18 +09:00
Hare	a653f0b7c6	Nest repeated playground fields	2026-07-09 19:06:28 +09:00
Hare	384d17b539	Replace playground examples	2026-07-09 19:02:11 +09:00
Hare	09a84264ab	Format playground examples	2026-07-09 18:54:29 +09:00
Hare	0a8c261545	Load playground wasm assets through Vite	2026-07-09 18:50:26 +09:00
Hare	a8a46998a8	Make build:wasm build all wasm packages	2026-07-09 18:46:24 +09:00
Hare	e4a9f80617	Dedupe CodeMirror dependencies	2026-07-09 18:43:09 +09:00
Hare	0e2a7b35d2	Add language tools package	2026-07-09 18:34:41 +09:00
Hare	ac99c4cb4e	Revert "Add Decodal formatter" This reverts commit `22f6bc1ab9`.	2026-07-09 17:46:24 +09:00
Hare	22f6bc1ab9	Add Decodal formatter	2026-07-09 17:39:32 +09:00
Hare	16006d000a	Move wasm package under packages	2026-07-09 04:13:08 +09:00
Hare	e4b9247c45	Extract CodeMirror language package	2026-07-09 03:49:44 +09:00
Hare	375bc80a57	Add package links to landing page	2026-07-09 03:31:20 +09:00
Hare	335ecde816	Fix JSR wasm package license	2026-07-09 03:29:27 +09:00
Hare	4142fcd46a	Prepare 0.1.2 release	2026-07-09 03:12:09 +09:00
Hare	2d06dc3277	Add source link to header	2026-07-09 03:00:30 +09:00
Hare	37237dc1f7	Add source link to footer	2026-07-09 02:59:32 +09:00
Hare	2966d5b979	Add site footer	2026-07-09 02:58:53 +09:00
Hare	ea858ad28e	Remove landing page eyebrow	2026-07-09 02:57:55 +09:00
Hare	871d342e15	Add site landing page	2026-07-09 02:55:50 +09:00
Hare	6d80c66144	Trim open issues to materialization	2026-07-09 02:46:28 +09:00
Hare	8e1cb01f52	Document Decodal components	2026-07-09 01:47:28 +09:00
Hare	26d8495631	Remove public tokenizer API	2026-07-09 01:09:40 +09:00
Hare	c4332ffb9d	Restore CodeMirror syntax highlighting	2026-07-09 00:38:31 +09:00
Hare	33ea8b94f9	Fix CodeMirror folding ranges	2026-07-09 00:04:34 +09:00
Hare	720c71157e	Fold Decodal delimited blocks from opener	2026-07-08 23:55:04 +09:00
Hare	ee031bd2e8	Add canonical grammar and CodeMirror playground	2026-07-08 23:41:26 +09:00
Hare	a07f4c48aa	Expose tokenizer for web highlighting	2026-07-08 19:50:04 +09:00
Hare	fe127428f9	Update generated WASM package README	2026-06-26 01:26:23 +09:00
Hare	0b76a600b1	Make Pages deploy script portable	2026-06-26 01:25:22 +09:00
Hare	ada3578a1d	Expose derive macro behind feature	2026-06-26 00:59:39 +09:00
Hare	b8404df047	Add typed Decodal derive support	2026-06-26 00:39:33 +09:00
Hare	87fef44c68	Make decodal the published library crate	2026-06-25 22:51:16 +09:00
Hare	6e2363632b	Prepare crates.io release metadata	2026-06-25 22:25:01 +09:00
Hare	c26f9ca50a	Add playground example loader	2026-06-25 03:39:40 +09:00
Hare	f928028007	Deploy Pages production branch by default	2026-06-25 03:12:37 +09:00
Hare	d8af980f7d	Add Cloudflare Pages deploy script	2026-06-25 02:49:15 +09:00
Hare	a2a6dee025	Show source names in diagnostics	2026-06-22 18:05:26 +09:00
Hare	cc5ab63922	Improve composition diagnostics	2026-06-22 17:37:51 +09:00
Hare	8b3df21cfa	Document lightweight runtime boundaries	2026-06-19 22:48:33 +09:00
Hare	01ad6dca52	Add array concat operator	2026-06-19 01:01:04 +09:00
Hare	6da0ec4c77	Fix inline code escaping	2026-06-18 23:55:11 +09:00
Hare	683151f6bd	Remove unimplemented operator note	2026-06-18 23:54:10 +09:00
Hare	9e728fb634	Document operator reference	2026-06-18 23:42:53 +09:00
Hare	2fe54bda62	Add logical and comparison expressions	2026-06-17 23:38:44 +09:00
Hare	3f7dd7c692	Add arithmetic expressions	2026-06-17 23:00:14 +09:00
Hare	dc28cddbff	Add dark theme support	2026-06-17 14:39:44 +09:00
Hare	aa6e5c51c1	Number manual sidebar navigation	2026-06-17 13:37:53 +09:00
Hare	4ab47e5719	Add multi-file playground imports	2026-06-17 10:17:00 +09:00
Hare	19c9de1601	Add site syntax highlighting	2026-06-17 07:39:00 +09:00
Hare	0e873fbd51	Migrate documentation site to Astro	2026-06-17 00:22:32 +09:00
Hare	4020b7c2d5	Add Svelte docs site and WASM playground	2026-06-17 00:07:11 +09:00