Document Decodal components

Remove public tokenizer API
Restore CodeMirror syntax highlighting
2026-07-09 01:47:28 +09:00 · 2026-07-09 01:09:40 +09:00 · 2026-07-09 00:38:31 +09:00 · 2026-07-09 00:04:34 +09:00 · 2026-07-08 23:55:04 +09:00 · 2026-07-08 23:41:26 +09:00
41 changed files with 1672 additions and 83 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@ -25,21 +25,32 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"

 [[package]]
 name = "decodal"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
+ "decodal-derive",
 "regex",
 ]

 [[package]]
 name = "decodal-cli"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
 "decodal",
 ]

+[[package]]
+name = "decodal-derive"
+version = "0.1.1"
+dependencies = [
+ "decodal",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "decodal-wasm"
-version = "0.1.0"
+version = "0.1.1"
 dependencies = [
 "decodal",
 "serde_json",
--- a/Cargo.toml
+++ b/Cargo.toml
@ -3,11 +3,12 @@ members = [
  "crates/decodal-core",
  "crates/decodal-cli",
  "crates/decodal-wasm",
+  "crates/decodal-derive",
 ]
 resolver = "2"

 [workspace.package]
-version = "0.1.0"
+version = "0.1.1"
 edition = "2024"
 rust-version = "1.85"
 license = "MIT OR Apache-2.0"
--- a/README.md
+++ b/README.md
@ -20,6 +20,33 @@ Embedded hosts should depend on `decodal` and provide imports with a `SourceLoad
 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.
--- a/crates/decodal-cli/Cargo.toml
+++ b/crates/decodal-cli/Cargo.toml
@ -20,4 +20,4 @@ default = []
 regex = ["decodal/regex"]

 [dependencies]
-decodal = { version = "0.1.0", path = "../decodal-core" }
+decodal = { version = "0.1.1", path = "../decodal-core" }
--- a/crates/decodal-core/Cargo.toml
+++ b/crates/decodal-core/Cargo.toml
@ -13,7 +13,9 @@ categories = ["config", "parser-implementations"]
 [features]
 default = ["std"]
 std = []
+derive = ["dep:decodal-derive"]
 regex = ["std", "dep:regex"]

 [dependencies]
+decodal-derive = { version = "0.1.1", path = "../decodal-derive", optional = true }
 regex = { version = "1.10", default-features = false, features = ["std", "unicode-perl"], optional = true }
--- a/crates/decodal-core/src/constraints.rs
+++ b/crates/decodal-core/src/constraints.rs
@ -70,7 +70,10 @@ pub fn normalize_constraints(

    if matches!(
        primitive,
-        Some((PrimitiveType::String | PrimitiveType::Bool, _))
+        Some((
+            PrimitiveType::String | PrimitiveType::Bool | PrimitiveType::Array,
+            _
+        ))
    ) && (lower.is_some() || upper.is_some())
    {
        let mut diagnostic = Diagnostic::new(
--- a/crates/decodal-core/src/embedding.rs
+++ b/crates/decodal-core/src/embedding.rs
@ -63,6 +63,18 @@ 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 +91,10 @@ impl HostValue {
        Self::abstract_with_constraint(Constraint::Type(PrimitiveType::Bool))
    }

+    pub fn array_type() -> Self {
+        Self::abstract_with_constraint(Constraint::Type(PrimitiveType::Array))
+    }
+
    pub fn builtin_predicate(name: impl Into<String>) -> Self {
        Self::abstract_with_constraint(Constraint::BuiltinPredicate(name.into()))
    }
@ -162,3 +178,38 @@ 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));
+    }
+}
--- a/crates/decodal-core/src/eval.rs
+++ b/crates/decodal-core/src/eval.rs
@ -1170,6 +1170,7 @@ fn primitive_type(name: &str) -> Option<PrimitiveType> {
        "Int" => Some(PrimitiveType::Int),
        "Float" => Some(PrimitiveType::Float),
        "Bool" => Some(PrimitiveType::Bool),
+        "Array" => Some(PrimitiveType::Array),
        _ => None,
    }
 }
@ -1250,6 +1251,9 @@ fn value_matches_primitive(value: &RuntimeValue, primitive: PrimitiveType) -> bo
        ) | (
            RuntimeValue::Concrete(ConcreteValue::Bool(_)),
            PrimitiveType::Bool
+        ) | (
+            RuntimeValue::Concrete(ConcreteValue::Array(_)),
+            PrimitiveType::Array
        )
    )
 }
--- a/crates/decodal-core/src/lexer.rs
+++ b/crates/decodal-core/src/lexer.rs
@ -62,6 +62,7 @@ pub struct Lexer<'a> {
 }

 impl<'a> Lexer<'a> {
+    #[cfg(test)]
    pub fn new(source: &'a str) -> Self {
        Self::with_source_id(SourceId(0), source)
    }
@ -93,6 +94,10 @@ impl<'a> Lexer<'a> {

    fn next_token(&mut self, previous: Option<&TokenKind>) -> Result<Token> {
        self.skip_ws_and_comments();
+        self.next_non_ws_token(previous)
+    }
+
+    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 {
--- a/crates/decodal-core/src/lib.rs
+++ b/crates/decodal-core/src/lib.rs
@ -7,22 +7,28 @@ pub mod constraints;
 pub mod diagnostic;
 pub mod embedding;
 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, format_diagnostic_with};
-pub use lexer::{Lexer, Token, TokenKind};
 pub use module::{EmptyLoader, LoadedSource, Module, SourceLoader};
 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")
--- a/crates/decodal-core/src/runtime.rs
+++ b/crates/decodal-core/src/runtime.rs
@ -79,6 +79,7 @@ pub enum PrimitiveType {
    Int,
    Float,
    Bool,
+    Array,
 }

 #[derive(Debug, Clone, PartialEq)]
--- a/crates/decodal-core/src/typed.rs
+++ b/crates/decodal-core/src/typed.rs
@ -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 for Vec<T> {
+    fn decodal_schema() -> HostValue {
+        HostValue::array_type()
+    }
+}
+
+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))
+    }
+}
--- a/crates/decodal-derive/Cargo.toml
+++ b/crates/decodal-derive/Cargo.toml
@ -0,0 +1,22 @@
+[package]
+name = "decodal-derive"
+version.workspace = true
+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 = "0.1", path = "../decodal-core" }
--- a/crates/decodal-derive/src/lib.rs
+++ b/crates/decodal-derive/src/lib.rs
@ -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
+        }
+    }
+}
--- a/crates/decodal-derive/tests/derive.rs
+++ b/crates/decodal-derive/tests/derive.rs
@ -0,0 +1,79 @@
+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>,
+}
+
+#[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");
+}
--- a/crates/decodal-wasm/Cargo.toml
+++ b/crates/decodal-wasm/Cargo.toml
@ -15,7 +15,7 @@ publish = false
 crate-type = ["cdylib", "rlib"]

 [dependencies]
-decodal = { version = "0.1.0", path = "../decodal-core" }
+decodal = { version = "0.1.1", path = "../decodal-core" }
 serde_json.workspace = true
 wasm-bindgen.workspace = true

--- a/doc/manual/souce/components.md
+++ b/doc/manual/souce/components.md
@ -0,0 +1,94 @@
+# 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/
+site/decodal-site/src/wasm/
+```
+
+The generated files in `site/decodal-site/src/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.
+
+## Web editor components
+
+The Web playground editor uses CodeMirror 6 with a generated Lezer parser.
+This is the source of syntax highlighting, folding, indentation, and editor syntax tree behavior in the browser UI.
+
+Important paths:
+
+```text
+editors/lezer-decodal/decodal.grammar
+site/decodal-site/src/lib/codemirror/decodal-parser.js
+site/decodal-site/src/lib/codemirror/decodal-parser.terms.js
+site/decodal-site/src/lib/codemirror/decodal.js
+```
+
+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.
+
+## What is not a public component
+
+The Rust lexer is an implementation detail of the Rust parser.
+Decodal does not expose a standalone public tokenizer API for editor tooling.
+Consumers that need syntax information should use the component that matches their environment:
+
+- Rust execution and embedding: `decodal`
+- Browser execution: `decodal-wasm`
+- Web editor syntax: Lezer / CodeMirror
+- General editor syntax: Tree-sitter
+
+This avoids having a separate token stream API whose behavior would have to be kept compatible with both runtime parsing and editor grammars.
--- a/doc/manual/souce/design/embedding-api.md
+++ b/doc/manual/souce/design/embedding-api.md
@ -17,7 +17,7 @@ let / function env
 ```

 Module top-level bindings shadow prelude bindings.
-Primitive type names such as `String`, `Int`, `Float`, and `Bool` are handled before environment lookup, so they are reserved and cannot be shadowed by host bindings.
+Primitive type names such as `String`, `Int`, `Float`, `Bool`, and `Array` are handled before environment lookup, so they are reserved and cannot be shadowed by host bindings.

 ## Global bindings

@ -87,6 +87,46 @@ Concrete(Object {

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

+## Typed Rust integration
+
+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:
+
+- `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.
+
 ## SourceLoader and prelude together

 `SourceLoader` and host prelude bindings are independent mechanisms.
--- a/doc/manual/souce/development.md
+++ b/doc/manual/souce/development.md
@ -23,10 +23,12 @@ cargo run -q -p decodal-cli --features regex -- examples/regex/main.dcdl
 ## crates.io release

 The primary crates.io package is `decodal`, which contains the embeddable library.
+`decodal-derive` provides optional derive macros for Rust struct integration.
 Workspace support crates such as `decodal-cli` and `decodal-wasm` are not published for 0.1.0.
 The project is dual licensed as `MIT OR Apache-2.0`.

 ```sh
+cargo publish -p decodal-derive
 cargo publish -p decodal
 ```

@ -36,6 +38,7 @@ Before publishing, run:
 cargo fmt --check
 cargo test
 cargo check -p decodal --no-default-features
+cargo publish -p decodal-derive --dry-run
 cargo publish -p decodal --dry-run
 ```

@ -55,8 +58,13 @@ 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/codemirror/decodal.js
+site/decodal-site/src/lib/codemirror/decodal-parser.js
 site/decodal-site/src/lib/docs.js
+site/decodal-site/src/lib/highlight.js
 crates/decodal-wasm/src/lib.rs
 ```

@ -77,6 +85,10 @@ site/decodal-site/src/wasm/

 These generated files are committed so the site can be built without requiring every consumer to regenerate the wasm package first.

+The playground editor uses CodeMirror 6 with the generated Lezer parser in `src/lib/codemirror/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.
+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
@ -149,12 +161,18 @@ 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 src/lib/codemirror/decodal-parser.js
+```
+
+5. Add or update corpus/tests/examples.
+6. Run Rust and site checks from the repository root.

 ## Development shell

--- a/doc/manual/souce/index.md
+++ b/doc/manual/souce/index.md
@ -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)
--- a/doc/manual/souce/language/grammar.md
+++ b/doc/manual/souce/language/grammar.md
@ -0,0 +1,111 @@
+# 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
+                   | 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 } , [ "," ] ] , "]" ;
+
+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.
--- a/doc/manual/souce/language/value/index.md
+++ b/doc/manual/souce/language/value/index.md
@ -9,9 +9,10 @@ name = String;
 retry = Int default 3;
 ratio = Float;
 enable = Bool default true;
+tags = Array;
 ```

-現在の primitive type は `String`、`Int`、`Float`、`Bool` である。
+現在の primitive type は `String`、`Int`、`Float`、`Bool`、`Array` である。
 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。
--- a/editors/lezer-decodal/README.md
+++ b/editors/lezer-decodal/README.md
@ -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 src/lib/codemirror/decodal-parser.js
+```
+
+The generated parser is committed with the site because the playground imports it directly.
--- a/editors/lezer-decodal/decodal.grammar
+++ b/editors/lezer-decodal/decodal.grammar
@ -0,0 +1,172 @@
+@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 |
+  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 }
+
+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 { "." }
+  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 }
--- a/editors/tree-sitter-decodal/README.md
+++ b/editors/tree-sitter-decodal/README.md
@ -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.
--- a/editors/tree-sitter-decodal/grammar.js
+++ b/editors/tree-sitter-decodal/grammar.js
@ -1,3 +1,6 @@
+// Tree-sitter implementation of the canonical EBNF grammar in
+// doc/manual/souce/language/grammar.md.
+
 const PREC = {
  DEFAULT: 1,
  PATCH: 2,
--- a/package.nix
+++ b/package.nix
@ -24,7 +24,7 @@ let
 in
 rustPlatform.buildRustPackage {
  pname = "decodal";
-  version = "0.1.0";
+  version = "0.1.1";

  src = lib.cleanSourceWith {
    src = srcRoot;
--- a/site/decodal-site/package-lock.json
+++ b/site/decodal-site/package-lock.json
@ -9,10 +9,17 @@
      "version": "0.1.0",
      "dependencies": {
        "@astrojs/check": "^0.9.4",
+        "@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",
        "astro": "^4.16.18",
+        "codemirror": "^6.0.2",
        "marked": "^12.0.2"
      },
      "devDependencies": {
+        "@lezer/generator": "^1.8.0",
        "wrangler": "^4.104.0"
      }
    },
@ -560,6 +567,87 @@
        "node": ">=16"
      }
    },
+    "node_modules/@codemirror/autocomplete": {
+      "version": "6.20.3",
+      "resolved": "https://registry.npmjs.org/@codemirror/autocomplete/-/autocomplete-6.20.3.tgz",
+      "integrity": "sha512-tlosUqb+3BbxCxZdu4tKeRghPFC+QM7q4X5YhKV2eCmPG+1r2F3f4AaSz5sCrFqUtX4Jh20VFTKecl16MgiV9g==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/language": "^6.0.0",
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.17.0",
+        "@lezer/common": "^1.0.0"
+      }
+    },
+    "node_modules/@codemirror/commands": {
+      "version": "6.10.4",
+      "resolved": "https://registry.npmjs.org/@codemirror/commands/-/commands-6.10.4.tgz",
+      "integrity": "sha512-Ryk9y9T0FFVF0cUGhAknveAyUOl/A1qReTFi+qPKtOh2Z9F4AUBz3XOrYD4ZEgZirdugVzHvd/2/Wcwy5OliTg==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/language": "^6.0.0",
+        "@codemirror/state": "^6.7.0",
+        "@codemirror/view": "^6.27.0",
+        "@lezer/common": "^1.1.0"
+      }
+    },
+    "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==",
+      "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/lint": {
+      "version": "6.9.7",
+      "resolved": "https://registry.npmjs.org/@codemirror/lint/-/lint-6.9.7.tgz",
+      "integrity": "sha512-28/+iWLYxKxsvGYhSYL7zaCZqLz5+FFFDq9tVsvGv9kv8RY4fFAchJ5WX9M3YrrRlTIsECjsXPqeNgnSmNP2dg==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.42.0",
+        "crelt": "^1.0.5"
+      }
+    },
+    "node_modules/@codemirror/search": {
+      "version": "6.7.1",
+      "resolved": "https://registry.npmjs.org/@codemirror/search/-/search-6.7.1.tgz",
+      "integrity": "sha512-uMe5UO6PamJtSHrXhhHOzSX3ReWtiJrva6GnPMwSOrZtiExb5X5eExhr2OUZQVvdxPsKpY3Ro2mFbQadpPWmHA==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.37.0",
+        "crelt": "^1.0.5"
+      }
+    },
+    "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==",
+      "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==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/state": "^6.7.0",
+        "crelt": "^1.0.6",
+        "style-mod": "^4.1.0",
+        "w3c-keyname": "^2.2.4"
+      }
+    },
    "node_modules/@cspotcode/source-map-support": {
      "version": "0.8.1",
      "resolved": "https://registry.npmjs.org/@cspotcode/source-map-support/-/source-map-support-0.8.1.tgz",
@ -1632,6 +1720,50 @@
        "@jridgewell/sourcemap-codec": "^1.4.14"
      }
    },
+    "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==",
+      "license": "MIT"
+    },
+    "node_modules/@lezer/generator": {
+      "version": "1.8.0",
+      "resolved": "https://registry.npmjs.org/@lezer/generator/-/generator-1.8.0.tgz",
+      "integrity": "sha512-/SF4EDWowPqV1jOgoGSGTIFsE7Ezdr7ZYxyihl5eMKVO5tlnpIhFcDavgm1hHY5GEonoOAEnJ0CU0x+tvuAuUg==",
+      "dev": true,
+      "license": "MIT",
+      "dependencies": {
+        "@lezer/common": "^1.1.0",
+        "@lezer/lr": "^1.3.0"
+      },
+      "bin": {
+        "lezer-generator": "src/lezer-generator.cjs"
+      }
+    },
+    "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==",
+      "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==",
+      "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==",
+      "license": "MIT"
+    },
    "node_modules/@nodelib/fs.scandir": {
      "version": "2.1.5",
      "resolved": "https://registry.npmjs.org/@nodelib/fs.scandir/-/fs.scandir-2.1.5.tgz",
@ -2981,6 +3113,21 @@
        "node": ">=6"
      }
    },
+    "node_modules/codemirror": {
+      "version": "6.0.2",
+      "resolved": "https://registry.npmjs.org/codemirror/-/codemirror-6.0.2.tgz",
+      "integrity": "sha512-VhydHotNW5w1UGK0Qj96BwSk/Zqbp9WbnyK2W/eVMv4QyF41INRGpjUhFJY7/uDNuudSc33a/PKr4iDqRduvHw==",
+      "license": "MIT",
+      "dependencies": {
+        "@codemirror/autocomplete": "^6.0.0",
+        "@codemirror/commands": "^6.0.0",
+        "@codemirror/language": "^6.0.0",
+        "@codemirror/lint": "^6.0.0",
+        "@codemirror/search": "^6.0.0",
+        "@codemirror/state": "^6.0.0",
+        "@codemirror/view": "^6.0.0"
+      }
+    },
    "node_modules/color": {
      "version": "4.2.3",
      "resolved": "https://registry.npmjs.org/color/-/color-4.2.3.tgz",
@ -3055,6 +3202,12 @@
        "node": ">= 0.6"
      }
    },
+    "node_modules/crelt": {
+      "version": "1.0.7",
+      "resolved": "https://registry.npmjs.org/crelt/-/crelt-1.0.7.tgz",
+      "integrity": "sha512-aK6BbWfhf4U/wCcLHKPJl/xa6VkVstRaPywWtMKGwuOLc/wZTyQYuoxgvZnNsBvv7Kg3YTBQYYBCggcviQczuA==",
+      "license": "MIT"
+    },
    "node_modules/cssesc": {
      "version": "3.0.0",
      "resolved": "https://registry.npmjs.org/cssesc/-/cssesc-3.0.0.tgz",
@ -6429,6 +6582,12 @@
        "node": ">=0.10.0"
      }
    },
+    "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==",
+      "license": "MIT"
+    },
    "node_modules/supports-color": {
      "version": "10.2.2",
      "resolved": "https://registry.npmjs.org/supports-color/-/supports-color-10.2.2.tgz",
@ -7126,6 +7285,12 @@
      "integrity": "sha512-/BpdSx+yCQGnCvecbyXdxHDkuk55/G3xwnC0GqY4gmQ3j+A+g8kzzgB4Nk/SINjqn6+waqw3EgbVF2QKExkRxQ==",
      "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==",
+      "license": "MIT"
+    },
    "node_modules/web-namespaces": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/web-namespaces/-/web-namespaces-2.0.1.tgz",
--- a/site/decodal-site/package.json
+++ b/site/decodal-site/package.json
@ -8,15 +8,22 @@
    "build": "astro build",
    "preview": "astro preview --host 0.0.0.0",
    "build:wasm": "wasm-pack build ../../crates/decodal-wasm --target web --out-dir ../../site/decodal-site/src/wasm --release",
-    "deploy": "npm run build && wrangler pages deploy dist --project-name ${CLOUDFLARE_PROJECT_NAME:-decodal-site} --branch ${CLOUDFLARE_BRANCH:-master}",
+    "deploy": "npm run build && node scripts/deploy-pages.mjs",
    "deploy:wasm": "npm run build:wasm && npm run deploy"
  },
  "dependencies": {
    "@astrojs/check": "^0.9.4",
+    "@codemirror/language": "^6.12.4",
+    "@codemirror/state": "^6.7.1",
+    "@codemirror/view": "^6.43.6",
+    "@lezer/highlight": "^1.2.3",
+    "@lezer/lr": "^1.4.10",
    "astro": "^4.16.18",
+    "codemirror": "^6.0.2",
    "marked": "^12.0.2"
  },
  "devDependencies": {
+    "@lezer/generator": "^1.8.0",
    "wrangler": "^4.104.0"
  }
 }
--- a/site/decodal-site/scripts/deploy-pages.mjs
+++ b/site/decodal-site/scripts/deploy-pages.mjs
@ -0,0 +1,12 @@
+import { spawnSync } from 'node:child_process';
+
+const projectName = process.env.CLOUDFLARE_PROJECT_NAME ?? 'decodal-site';
+const branch = process.env.CLOUDFLARE_BRANCH ?? 'master';
+
+const result = spawnSync(
+  'wrangler',
+  ['pages', 'deploy', 'dist', '--project-name', projectName, '--branch', branch],
+  { stdio: 'inherit', shell: process.platform === 'win32' },
+);
+
+process.exit(result.status ?? 1);
--- a/site/decodal-site/src/lib/codemirror/decodal-parser.js
+++ b/site/decodal-site/src/lib/codemirror/decodal-parser.js
@ -0,0 +1,16 @@
+// This file was generated by lezer-generator. You probably shouldn't edit it.
+import {LRParser} from "@lezer/lr"
+export const parser = LRParser.deserialize({
+  version: 14,
+  states: "7vQYQPOOO#nQPO'#CaOOQO'#Cr'#CrO$wQPO'#CyO&UQPO'#DOO&^QPO'#DSO&eQPO'#DWO&mQPO'#CqO$wQPO'#DcO&wQPO'#DhOOQO'#Cq'#CqOOQO'#Cp'#CpO&|QPO'#CoO$wQPO'#CoOOQO'#Cn'#CnO)fQPO'#CmO.XQPO'#ClO0]QPO'#CkOOQO'#Cj'#CjO2TQPO'#CiO3xQPO'#ChO5jQPO'#CgO7UQPO'#CfOOQO'#Ce'#CeO7`QPO'#C`O7eQPO'#C_OOQO'#Dz'#DzQYQPOOO8xQPO'#D{O8}QPO,58{OOQO,59e,59eO9VQPO'#CaOOQO,59j,59jO9_QPO,59jOOQO,59n,59nO9gQPO,59nO9oQPO'#EOO9tQPO'#DYO9|QPO,59rO:RQPO'#CqO:`QPO'#D^O:hQQO,59vO:mQPO,59vO:rQPO,59]O:wQPO,59}OOQO,5:S,5:SO:|QPO'#DjOOQO,59[,59[O;TQPO,59[OOQO,59Z,59ZO$wQPO,59YO$wQPO,59XO$wQPO,59WOOQO'#Dr'#DrO$wQPO,59VO$wQPO,59UO$wQPO,59TO$wQPO,59SO$wQPO,59RO$wQPO,59QO$wQPO,58zOOQO,58y,58yOOQO-E7x-E7xOOQO,5:g,5:gOOQO-E7y-E7yO;YQPO1G/UO;bQPO1G/UOOQO1G/U1G/UO;jQPO1G/YO;qQPO1G/YOOQO1G/Y1G/YOOQO,5:j,5:jOOQO-E7|-E7|O$wQPO1G/^O$wQPO,59yO;yQPO,59xO<RQPO,59xO$wQPO1G/bO<ZQQO1G/bOOQO1G.w1G.wO<`QPO1G/iO<jQPO'#DkOOQO,5:U,5:UO<rQPO,5:UOOQO1G.v1G.vOOQO1G.t1G.tO<wQPO1G.sO@_QPO1G.rOAyQPO1G.qOOQO1G.p1G.pOCqQPO1G.oOEfQPO1G.nOFxQPO1G.mOOQO1G.l1G.lOOQO1G.f1G.fOOQO1G.s1G.sOOQO1G.r1G.rOOQO1G.q1G.qOOQO1G.o1G.oOOQO1G.n1G.nOOQO1G.m1G.mOOQO,5:h,5:hOOQO7+$p7+$pOHfQPO7+$pOOQO-E7z-E7zOOQO,5:i,5:iOOQO7+$t7+$tOHnQPO7+$tOOQO-E7{-E7{OOQO7+$x7+$xOOQO1G/e1G/eOHuQPO'#D_OOQO,5:k,5:kOHzQPO1G/dOOQO-E7}-E7}OOQO7+$|7+$|O$wQPO7+$|OOQO'#Df'#DfOISQPO'#DeOOQO7+%T7+%TOIXQPO7+%TOIaQPO,5:VOIhQPO,5:VOOQO1G/p1G/pOOQO<<H[<<H[PIpQPO'#D|OOQO<<H`<<H`P$wQPO'#D}PIuQPO'#EPOOQO<<Hh<<HhO$wQPO,5:POIzQPO<<HoOJUQPO<<HoOOQO<<Ho<<HoOJ^QPO1G/qOOQO1G/k1G/kOOQO,5:l,5:lOOQOAN>ZAN>ZOJeQPOAN>ZOOQO-E8O-E8OOOQOG23uG23uP<cQPO'#EQO$wQPO,59XO$wQPO,59WO$wQPO,59VO$wQPO,59TO$wQPO,59SO$wQPO,59ROJoQPO1G.rOKVQPO'#ClOKjQPO'#CkOL^QPO'#ChOM^QPO'#CgONaQPO'#CfO$wQPO,59WO$wQPO,59UO$wQPO,59QO! jQPO1G.qO!!QQPO'#CkO!#_QPO'#CiO$wQPO,59VO$wQPO,59UO$wQPO,59TO$wQPO,59SO$wQPO,59RO$wQPO,59QO$wQPO,58zO!$[QPO1G.oO!$rQPO1G.nO!%YQPO1G.mO!%zQPO'#CiO!&rQPO'#ChO!'gQPO'#CgO!(XQPO'#CfO!(vQPO'#C`",
+  stateData: "!)Y~O!wOSPOS~OUPOgQOhQOiQOjQOkQOlQOnROoROpROqROsSOwTO{UO!PVO!WWO!]XO!`]O!a]O~OneXoeXpeXqeX!PeX!aeX!beX!ceX!deX!eeX!geX!heX!ieX!jeX!keX!leX!meX~OVlOUeXWTXgeXheXieXjeXkeXleXseXteXweX{eX!WeX!]eX!`eX!ueX~P!gOUYOgQOhQOiQOjQOkQOlQOnROoROpROqROsSOwTO{UO!PVO!WWO!]XO!`]O!a]O~OUoOupO~OyrO~P$wOUoO}|P~OUwO!TyO~P]Og}O~OV!QO!P!OOUcXgcXhcXicXjcXkcXlcXncXocXpcXqcXscXtcXwcX{cX!WcX!]cX!`cX!acX!bcX!ccX!dcX!ecX!gcX!hcX!icX!jcX!kcX!lcX!mcX!ucXxcXycX!TcXucX!ScX~O!b!SO!c!SOUaXgaXhaXiaXjaXkaXlaXnaXoaXpaXqaXsaXtaXwaX{aX!PaX!WaX!]aX!`aX!aaX!daX!eaX!gaX!haX!iaX!jaX!kaX!laX!maX!uaXVaXxaXyaX!TaXuaX!SaX~OU`Xg`Xh`Xi`Xj`Xk`Xl`Xn`Xo`Xp`Xq`Xs`Xt`Xw`X{`X!P`X!W`X!]`X!``X!e`X!g`X!h`X!i`X!j`X!k`X!l`X!m`X!u`Xx`Xy`X!T`Xu`X!S`X~O!a!TO!d!TO~P,OOn!VOo!VOp!VOq!VO!g!VO!h!VOU_Xg_Xh_Xi_Xj_Xk_Xl_Xs_Xt_Xw_X{_X!P_X!W_X!]_X!`_X!a_X!i_X!j_X!k_X!l_X!m_X!u_X~O!e!UO~P.cOU]Xg]Xh]Xi]Xj]Xk]Xl]Xn]Xo]Xp]Xq]Xs]Xt]Xw]X{]X!P]X!W]X!]]X!`]X!a]X!j]X!k]X!l]X!m]X!u]X~O!i!XO~P0dOU[Xg[Xh[Xi[Xj[Xk[Xl[Xn[Xo[Xp[Xq[Xs[Xt[Xw[X{[X!P[X!W[X!][X!`[X!a[X!k[X!l[X!m[X!u[X~O!j!YO~P2[OUZXgZXhZXiZXjZXkZXlZXnZXoZXpZXqZXsZXtZXwZX{ZX!PZX!WZX!]ZX!`ZX!aZX!lZX!mZX!uZX~O!k!ZO~P4POUYXgYXhYXiYXjYXkYXlYXnYXoYXpYXqYXsYXtYXwYX{YX!PYX!WYX!]YX!`YX!aYX!uYX~O!l![O!m!]O~P5qOW!^O~Ot!_OURXgRXhRXiRXjRXkRXlRXnRXoRXpRXqRXsRXwRX{RX!PRX!WRX!]RX!`RX!aRX!uRX~OU!aO~OVlOWTa~OVlOWTX~Ot!cOu!eO~Ox!fOy!hO~Ot!iO~OUoO}|X~O}!kO~O!S!lOVeX!TeX~P!gOx!mO!T!QX~O!U!oO~O!T!pO~O!T!qO~Os!rO~O!T!tO~P$wOU!vO~OUoOu#YO~Ot#ZOu#YO~Oy#^O~P$wOx#_Oy#^O~OU#cO!T!Qa~Ox#eO!T!Qa~O!U#hO~Ou#kO!Z#iO~P$wOx#mO!T!_X~O!T#oO~O!b!SO!c!SOUaigaihaiiaijaikailainaioaipaiqaisaitaiwai{ai!Pai!Wai!]ai!`ai!aai!dai!eai!gai!hai!iai!jai!kai!lai!mai!uaixaiyai!Taiuai!Sai~O!d!TOn`io`ip`iq`is`it`i!e`i!g`i!h`i!i`i!j`i!k`i!l`i!m`i~OU`ig`ih`ii`ij`ik`il`iw`i{`i!P`i!W`i!]`i!``i!a`i!u`i~P?^Os_it_i!i_i!j_i!k_i!l_i!m_i~O!e!UOU_ig_ih_ii_ij_ik_il_in_io_ip_iq_iw_i{_i!P_i!W_i!]_i!`_i!a_i!u_i~PAbOs]it]i!j]i!k]i!l]i!m]i~O!i!XOU]ig]ih]ii]ij]ik]il]in]io]ip]iq]iw]i{]i!P]i!W]i!]]i!`]i!a]i!u]i~PC]Os[it[i!k[i!l[i!m[i~O!j!YOU[ig[ih[ii[ij[ik[il[in[io[ip[iq[iw[i{[i!P[i!W[i!][i!`[i!a[i!u[i~PETO!k!ZOUZigZihZiiZijZikZilZinZioZipZiqZisZitZiwZi{Zi!PZi!WZi!]Zi!`Zi!aZi!lZi!mZi!uZi~OUoOu#pO~Oy#rO~P$wO!S!lO~OU#cO!T!Qi~O!S#vO~Ot#wOu#yO~O!T!_a~P$wOx#zO!T!_a~OUoO~OU#cO~Ou#}O!Z#iO~P$wOt$OOu#}O~O!T!_i~P$wOu$QO!Z#iO~P$wO!a!TOx`iy`i!T`iu`i!S`i~P?^O!a$SO!d$SOV`X!b`X!c`X~P,OO!e$TOV_X!b_X!c_X!d_Xx_Xy_X!T_Xu_X!S_X~P.cO!j$VOV[X!b[X!c[X!d[X!e[X!g[X!h[X!i[Xx[Xy[X!T[Xu[X!S[X~P2[O!k$WOVZX!bZX!cZX!dZX!eZX!gZX!hZX!iZX!jZXxZXyZX!TZXuZX!SZX~P4PO!l$XO!m$bOVYX!bYX!cYX!dYX!eYX!gYX!hYX!iYX!jYX!kYXxYXyYX!TYXuYX!SYX~P5qO!e$`Ox_iy_i!T_iu_i!S_i~PAbOn!VOo!VOp!VOq!VO!e$`O!g!VO!h!VOx_Xy_X!i_X!j_X!k_X!l_X!m_X!T_Xs_Xt_Xu_X!S_X~O!i$aOV]X!b]X!c]X!d]X!e]X!g]X!h]Xx]Xy]X!T]Xu]X!S]X~P0dO!i$gOx]iy]i!T]iu]i!S]i~PC]O!j$hOx[iy[i!T[iu[i!S[i~PETO!k$iOxZiyZi!lZi!mZi!TZisZitZiuZi!SZi~O!i$gOx]Xy]X!j]X!k]X!l]X!m]X!T]Xs]Xt]Xu]X!S]X~O!j$hOx[Xy[X!k[X!l[X!m[X!T[Xs[Xt[Xu[X!S[X~O!k$iOxZXyZX!lZX!mZX!TZXsZXtZXuZX!SZX~O!l$jO!m$kOxYXyYX!TYXsYXtYXuYX!SYX~OW$lO~O{}!W!]!mjkih!ZUj~",
+  goto: "3l!uPPP!v!z#[PPP#h$m%]%}&x'v(w)s*z,S-Y.b/f0jPPPPPP0jPPPP0jPPP0jPPP0jP1nP0jP1q1tPPP0jP1|2UP0jP2[2_PPPPPP2bPPPPPPP2k2q2x3O3Y3`3fTjOkSiOkQqSStUuV#X!c#Z#qShOk]$tSUu!c#Z#qSiOkQnRQsTQ{VQ|WQ!s!OS#Q!^$lY#]!f#_#m#s#zQ#a!kQ#b!lQ#g!oW#i!r#w$O$RQ#u#hR#{#v!OgORTVWk!O!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$lV#P!]$b$kWfOk!]!^Y$_R!k!o#h$bs$sTVW!O!f!l!r#_#m#s#v#w#z$O$R$k$lWeOk!]!^Q#O![Q#W$XY$^R!k!o#h$bQ$o$js$rTVW!O!f!l!r#_#m#s#v#w#z$O$R$k$lYdOk![!]!^Q!}!ZQ#V$W[$]R!k!o#h$X$bQ$n$iu$qTVW!O!f!l!r#_#m#s#v#w#z$O$R$j$k$l[cOk!Z![!]!^Q!|!YQ#U$V^$eR!k!o#h$W$X$bQ$m$hw$pTVW!O!f!l!r#_#m#s#v#w#z$O$R$i$j$k$l!hbORTVWk!O!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$V$W$X$b$h$i$j$k$lV!{!X$a$g`aOk!X!Y!Z![!]!^Q!z!WQ#T$Ub$[R!k!o#h$V$W$X$a$bQ$c$f{$dTVW!O!f!l!r#_#m#s#v#w#z$O$R$g$h$i$j$k$l!``OTVWk!O!W!X!Y!Z![!]!^!f!l!r#_#m#s#v#w#z$O$R$f$g$h$i$j$k$lQ!y!UQ#S$TQ$Y$`e$ZR!k!o#h$U$V$W$X$a$b!z_ORTVWk!O!U!W!X!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$T$U$V$W$X$`$a$b$f$g$h$i$j$k$lQ!x!TR#R$S#O^ORTVWk!O!T!U!W!X!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$S$T$U$V$W$X$`$a$b$f$g$h$i$j$k$lQ!R]R!w!S#T[ORTVW]k!O!S!T!U!W!X!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$S$T$U$V$W$X$`$a$b$f$g$h$i$j$k$l#TZORTVW]k!O!S!T!U!W!X!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$S$T$U$V$W$X$`$a$b$f$g$h$i$j$k$l#TYORTVW]k!O!S!T!U!W!X!Y!Z![!]!^!f!k!l!o!r#_#h#m#s#v#w#z$O$R$S$T$U$V$W$X$`$a$b$f$g$h$i$j$k$lRvURzVQxVV#d!m#e#tQ#l!rV#|#w$O$RX#j!r#w$O$RR!P[R!u!OQ!WaQ$U$[R$f$dQkOR!`kSmPoR!bmQ!dqR#[!dQ!gsS#`!g#nR#n!sQuUR!juQ!nxR#f!nQ#x#lR$P#x",
+  nodeNames: "⚠ Comment Source Statement FieldDefinition FieldPath Identifier Dot Equal Expression DefaultExpression PatchExpression ComposeExpression LogicalOrExpression LogicalAndExpression ComparisonExpression ConcatExpression AdditiveExpression MultiplicativeExpression UnaryExpression PostfixExpression PrimaryExpression Literal String Integer Float True False Regex ComparisonConstraint Lt Lte Gt Gte Object LBrace Semicolon RBrace Array LBracket Comma RBracket LetExpression Let FieldDefinitionList In FunctionExpression LParen ParameterList Parameter Colon RParen Arrow MatchExpression Match MatchArm Pattern Underscore ImportExpression Import CallSuffix ArgumentList Bang Minus Star Slash Plus PlusPlus CompareOperator EqualEqual BangEqual AmpAmp PipePipe Amp SlashSlash Default",
+  maxTerm: 85,
+  skippedNodes: [0,1],
+  repeatNodeCount: 7,
+  tokenData: "=T~R!PX^$Upq$Uqr$yrs%Wst&zvw'cxy'pyz'uz{'z{|(P|}(^}!O(c!O!P(h!P!Q(m!Q![+T![!]+n!]!^+s!^!_+x!_!`,V!`!a,l!c!},y!}#O-[#P#Q-a#R#S-f#T#W,y#W#X-y#X#Y,y#Y#Z1Z#Z#],y#]#^3k#^#`,y#`#a6}#a#b8b#b#h,y#h#i:r#i#o,y#o#p<n#p#q<s#q#r=O#y#z$U$f$g$U#BY#BZ$U$IS$I_$U$I|$JO$U$JT$JU$U$KV$KW$U&FU&FV$U~$ZY!w~X^$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!`~!_!`%R~%WO!h~~%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!k~vw'k~'pO!i~~'uO!P~~'zO!T~~(PO!b~~(UP!d~{|(X~(^O!e~~(cOx~~(hO!a~~(mOV~~(rW!c~OY)[Z!P)[!P!Q+O!Q#O)[#O#P)|#P;'S)[;'S;=`*x<%lO)[~)_WOY)[Z!P)[!P!Q)w!Q#O)[#O#P)|#P;'S)[;'S;=`*x<%lO)[~)|Ol~~*PRO;'S)[;'S;=`*Y;=`O)[~*]XOY)[Z!P)[!P!Q)w!Q#O)[#O#P)|#P;'S)[;'S;=`*x;=`<%l)[<%lO)[~*{P;=`<%l)[~+TO!l~~+YQh~!O!P+`!Q![+T~+cP!Q![+f~+kPi~!Q![+f~+sO!S~~+xOt~~+}Pn~!_!`,Q~,VOo~~,[QWP!_!`,b!`!a,g~,gO!g~Q,lO!UQ~,qPp~!_!`,t~,yOq~~-OSU~!Q![,y!c!},y#R#S,y#T#o,y~-aOw~~-fOy~~-mS!Z~U~!Q![,y!c!},y#R#S,y#T#o,y~.OUU~!Q![,y!c!},y#R#S,y#T#X,y#X#Y.b#Y#o,y~.gUU~!Q![,y!c!},y#R#S,y#T#Y,y#Y#Z.y#Z#o,y~/OTU~!Q![,y!c!},y#R#S,y#T#U/_#U#o,y~/dUU~!Q![,y!c!},y#R#S,y#T#i,y#i#j/v#j#o,y~/{UU~!Q![,y!c!},y#R#S,y#T#`,y#`#a0_#a#o,y~0dUU~!Q![,y!c!},y#R#S,y#T#h,y#h#i0v#i#o,y~0}S!m~U~!Q![,y!c!},y#R#S,y#T#o,y~1`TU~!Q![,y!c!},y#R#S,y#T#U1o#U#o,y~1tUU~!Q![,y!c!},y#R#S,y#T#`,y#`#a2W#a#o,y~2]UU~!Q![,y!c!},y#R#S,y#T#g,y#g#h2o#h#o,y~2tUU~!Q![,y!c!},y#R#S,y#T#X,y#X#Y3W#Y#o,y~3_Sk~U~!Q![,y!c!},y#R#S,y#T#o,y~3pVU~!Q![,y!c!},y#R#S,y#T#a,y#a#b4V#b#c6j#c#o,y~4[UU~!Q![,y!c!},y#R#S,y#T#d,y#d#e4n#e#o,y~4sUU~!Q![,y!c!},y#R#S,y#T#c,y#c#d5V#d#o,y~5[UU~!Q![,y!c!},y#R#S,y#T#f,y#f#g5n#g#o,y~5sUU~!Q![,y!c!},y#R#S,y#T#h,y#h#i6V#i#o,y~6^S!]~U~!Q![,y!c!},y#R#S,y#T#o,y~6qS}~U~!Q![,y!c!},y#R#S,y#T#o,y~7SUU~!Q![,y!c!},y#R#S,y#T#X,y#X#Y7f#Y#o,y~7kUU~!Q![,y!c!},y#R#S,y#T#h,y#h#i7}#i#o,y~8US{~U~!Q![,y!c!},y#R#S,y#T#o,y~8gTU~!Q![,y!c!},y#R#S,y#T#U8v#U#o,y~8{UU~!Q![,y!c!},y#R#S,y#T#h,y#h#i9_#i#o,y~9dUU~!Q![,y!c!},y#R#S,y#T#V,y#V#W9v#W#o,y~9{UU~!Q![,y!c!},y#R#S,y#T#[,y#[#]:_#]#o,y~:fS!W~U~!Q![,y!c!},y#R#S,y#T#o,y~:wUU~!Q![,y!c!},y#R#S,y#T#f,y#f#g;Z#g#o,y~;`UU~!Q![,y!c!},y#R#S,y#T#i,y#i#j;r#j#o,y~;wUU~!Q![,y!c!},y#R#S,y#T#X,y#X#Y<Z#Y#o,y~<bSj~U~!Q![,y!c!},y#R#S,y#T#o,y~<sOs~~<vP#p#q<y~=OO!j~~=TOu~",
+  tokenizers: [0, 1],
+  topRules: {"Source":[0,2]},
+  tokenPrec: 2481
+})
--- a/site/decodal-site/src/lib/codemirror/decodal-parser.terms.js
+++ b/site/decodal-site/src/lib/codemirror/decodal-parser.terms.js
@ -0,0 +1,77 @@
+// 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,
+  Array = 38,
+  LBracket = 39,
+  Comma = 40,
+  RBracket = 41,
+  LetExpression = 42,
+  Let = 43,
+  FieldDefinitionList = 44,
+  In = 45,
+  FunctionExpression = 46,
+  LParen = 47,
+  ParameterList = 48,
+  Parameter = 49,
+  Colon = 50,
+  RParen = 51,
+  Arrow = 52,
+  MatchExpression = 53,
+  Match = 54,
+  MatchArm = 55,
+  Pattern = 56,
+  Underscore = 57,
+  ImportExpression = 58,
+  Import = 59,
+  CallSuffix = 60,
+  ArgumentList = 61,
+  Bang = 62,
+  Minus = 63,
+  Star = 64,
+  Slash = 65,
+  Plus = 66,
+  PlusPlus = 67,
+  CompareOperator = 68,
+  EqualEqual = 69,
+  BangEqual = 70,
+  AmpAmp = 71,
+  PipePipe = 72,
+  Amp = 73,
+  SlashSlash = 74,
+  Default = 75
--- a/site/decodal-site/src/lib/codemirror/decodal.js
+++ b/site/decodal-site/src/lib/codemirror/decodal.js
@ -0,0 +1,69 @@
+import { LRLanguage, LanguageSupport, HighlightStyle, syntaxHighlighting, foldNodeProp, indentNodeProp } from '@codemirror/language';
+import { styleTags, tags as t } from '@lezer/highlight';
+import { parser } from './decodal-parser.js';
+
+const parserWithMetadata = parser.configure({
+  props: [
+    styleTags({
+      'Let In Match Import Default': t.keyword,
+      'True False': t.bool,
+      Identifier: t.variableName,
+      String: t.string,
+      Regex: t.regexp,
+      'Integer Float': t.number,
+      Comment: t.lineComment,
+      'Plus Minus Star Slash PlusPlus Equal EqualEqual Bang BangEqual Amp AmpAmp PipePipe SlashSlash Gt Gte Lt Lte Arrow': t.operator,
+      'LBrace RBrace': t.brace,
+      'LBracket RBracket': t.squareBracket,
+      'LParen RParen': t.paren,
+      'Semicolon Comma Dot Colon': t.punctuation,
+    }),
+    indentNodeProp.add({
+      Object: context => context.column(context.node.from) + context.unit,
+      Array: context => context.column(context.node.from) + context.unit,
+      MatchExpression: context => context.column(context.node.from) + context.unit,
+      LetExpression: context => context.column(context.node.from) + context.unit,
+    }),
+    foldNodeProp.add({
+      Object: foldDelimited('{', '}'),
+      Array: foldDelimited('[', ']'),
+      MatchExpression: foldDelimited('{', '}'),
+    }),
+  ],
+});
+
+function foldDelimited(open, close) {
+  return (node, state) => {
+    const text = state.doc.sliceString(node.from, node.to);
+    const openIndex = text.indexOf(open);
+    const closeIndex = text.lastIndexOf(close);
+    if (openIndex < 0 || closeIndex <= openIndex) return null;
+    const from = node.from + openIndex + open.length;
+    const to = node.from + closeIndex;
+    return from < to ? { from, to } : null;
+  };
+}
+
+export const decodalLanguage = LRLanguage.define({
+  parser: parserWithMetadata,
+  languageData: {
+    commentTokens: { line: '#' },
+    closeBrackets: { brackets: ['(', '[', '{', '"'] },
+  },
+});
+
+export const decodalHighlightStyle = HighlightStyle.define([
+  { tag: t.keyword, color: '#93c5fd', fontWeight: '700' },
+  { tag: t.variableName, color: 'inherit' },
+  { tag: t.bool, color: '#fbbf24' },
+  { tag: t.number, color: '#fbbf24' },
+  { tag: t.string, color: '#86efac' },
+  { tag: t.regexp, color: '#86efac' },
+  { tag: t.lineComment, color: '#94a3b8', fontStyle: 'italic' },
+  { tag: t.operator, color: '#f9a8d4' },
+  { tag: [t.brace, t.squareBracket, t.paren, t.punctuation], color: '#f9a8d4' },
+]);
+
+export function decodal() {
+  return new LanguageSupport(decodalLanguage, [syntaxHighlighting(decodalHighlightStyle)]);
+}
--- a/site/decodal-site/src/lib/docs.js
+++ b/site/decodal-site/src/lib/docs.js
@ -19,11 +19,13 @@ export const docs = Object.fromEntries(

 export const nav = [
  { title: 'Introduction', slug: 'introduction' },
+  { title: 'Components', slug: 'components' },
  {
    title: 'Language Specification',
    slug: 'language',
    children: [
      { title: 'Syntax', slug: 'language/syntax' },
+      { title: 'Grammar', slug: 'language/grammar' },
      {
        title: 'Value',
        slug: 'language/value',
--- a/site/decodal-site/src/lib/highlight.js
+++ b/site/decodal-site/src/lib/highlight.js
@ -25,6 +25,66 @@ export function highlightCode(code, language = '') {
  return escapeHtml(code);
 }

+export function highlightDecodalTokens(source, tokens) {
+  let html = '';
+  let cursor = 0;
+  for (const token of tokens) {
+    if (token.start > cursor) html += escapeHtml(source.slice(cursor, token.start));
+    const text = source.slice(token.start, token.end);
+    const kind = tokenClass(token.kind, text);
+    html += kind ? `<span class="${kind}">${escapeHtml(text)}</span>` : escapeHtml(text);
+    cursor = token.end;
+  }
+  if (cursor < source.length) html += escapeHtml(source.slice(cursor));
+  return html;
+}
+
+function tokenClass(kind, text) {
+  if (['let', 'in', 'fn', 'match', 'import', 'default'].includes(kind)) return 'tok-keyword';
+  if (kind === 'ident' && ['String', 'Int', 'Float', 'Bool', 'Array'].includes(text)) return 'tok-type';
+  if (kind === 'ident') return '';
+  if (['true', 'false'].includes(kind)) return 'tok-literal';
+  if (['int', 'float'].includes(kind)) return 'tok-number';
+  if (kind === 'string') return 'tok-string';
+  if (kind === 'regex') return 'tok-regex';
+  if (kind === 'comment') return 'tok-comment';
+  if (
+    [
+      'equal',
+      'equal_equal',
+      'bang',
+      'bang_equal',
+      'arrow',
+      'amp',
+      'amp_amp',
+      'pipe_pipe',
+      'plus',
+      'plus_plus',
+      'minus',
+      'star',
+      'slash',
+      'slash_slash',
+      'gt',
+      'gte',
+      'lt',
+      'lte',
+      'dot',
+      'colon',
+      'semicolon',
+      'comma',
+      'l_brace',
+      'r_brace',
+      'l_bracket',
+      'r_bracket',
+      'l_paren',
+      'r_paren',
+    ].includes(kind)
+  ) {
+    return 'tok-operator';
+  }
+  return '';
+}
+
 export function highlightDecodal(source) {
  let html = '';
  let index = 0;
--- a/site/decodal-site/src/pages/playground.astro
+++ b/site/decodal-site/src/pages/playground.astro
@ -29,13 +29,10 @@ import ManualLayout from '../layouts/ManualLayout.astro';
        <button id="delete-file" class="danger-button" type="button">Delete file</button>
      </aside>

-      <label class="pane input-pane">
+      <section class="pane input-pane">
        <span id="active-file">Input</span>
-        <div class="editor-wrap">
-          <pre id="source-highlight" aria-hidden="true"></pre>
-          <textarea id="source" spellcheck="false"></textarea>
-        </div>
-      </label>
+        <div id="editor" class="code-editor"></div>
+      </section>

      <section class="pane output-pane">
        <span>Output</span>
--- a/site/decodal-site/src/scripts/playground.js
+++ b/site/decodal-site/src/scripts/playground.js
@ -1,12 +1,13 @@
 import init, { evaluateProject } from '../wasm/decodal_wasm.js';
-import { highlightDecodal } from '../lib/highlight.js';
+import { EditorView, basicSetup } from 'codemirror';
+import { keymap } from '@codemirror/view';
+import { decodal } from '../lib/codemirror/decodal.js';
 import { playgroundExamples } from './playground-examples.js';

 const STORAGE_KEY = 'decodal-playground-project-v1';
 const starterProject = playgroundExamples[0];

-const source = document.getElementById('source');
-const sourceHighlight = document.getElementById('source-highlight');
+const editorHost = document.getElementById('editor');
 const output = document.getElementById('output');
 const run = document.getElementById('run');
 const status = document.getElementById('status');
@ -19,6 +20,63 @@ const loadExample = document.getElementById('load-example');

 const project = loadProject();

+const editorTheme = EditorView.theme({
+  '&': {
+    backgroundColor: '#0f172a',
+    color: '#e5e7eb',
+    height: '100%',
+  },
+  '.cm-scroller': {
+    fontFamily: 'ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace',
+    fontSize: '14px',
+    lineHeight: '1.5',
+    overflow: 'auto',
+  },
+  '.cm-content': {
+    caretColor: '#e5e7eb',
+    minHeight: '100%',
+    padding: '12px',
+  },
+  '.cm-gutters': {
+    backgroundColor: '#111827',
+    borderRight: '1px solid #334155',
+    color: '#94a3b8',
+  },
+  '&.cm-focused': {
+    outline: 'none',
+  },
+  '&.cm-focused .cm-cursor': {
+    borderLeftColor: '#e5e7eb',
+  },
+  '&.cm-focused .cm-selectionBackground, .cm-selectionBackground, ::selection': {
+    backgroundColor: 'rgb(59 130 246 / 0.35)',
+  },
+}, { dark: true });
+
+const editor = new EditorView({
+  doc: project.files[project.activePath] ?? '',
+  parent: editorHost,
+  extensions: [
+    basicSetup,
+    decodal(),
+    editorTheme,
+    keymap.of([
+      {
+        key: 'Mod-Enter',
+        run() {
+          execute();
+          return true;
+        },
+      },
+    ]),
+    EditorView.updateListener.of((update) => {
+      if (!update.docChanged) return;
+      project.files[project.activePath] = update.state.doc.toString();
+      saveProject();
+    }),
+  ],
+});
+
 for (const example of playgroundExamples) {
  const option = document.createElement('option');
  option.value = example.id;
@ -29,7 +87,6 @@ exampleSelect.value = starterProject.id;

 setActiveFile(project.activePath);
 renderFileTree();
-updateHighlight();

 function loadProject() {
  try {
@ -83,30 +140,36 @@ function normalizePath(path) {
  return parts.join('/');
 }

+function getEditorText() {
+  return editor.state.doc.toString();
+}
+
+function setEditorText(value) {
+  editor.dispatch({
+    changes: {
+      from: 0,
+      to: editor.state.doc.length,
+      insert: value,
+    },
+  });
+}
+
 function setActiveFile(path) {
  const normalized = normalizePath(path);
  if (project.files[normalized] === undefined) return;
+  if (project.activePath && project.files[project.activePath] !== undefined) {
+    project.files[project.activePath] = getEditorText();
+  }
  project.activePath = normalized;
-  source.value = project.files[normalized];
+  setEditorText(project.files[normalized]);
  activeFile.textContent = normalized;
  deleteFile.disabled = Object.keys(project.files).length <= 1;
-  updateHighlight();
-  syncHighlightScroll();
  renderFileTree();
  saveProject();
 }

-function updateHighlight() {
-  sourceHighlight.innerHTML = `${highlightDecodal(source.value)}\n`;
-}
-
-function syncHighlightScroll() {
-  sourceHighlight.scrollTop = source.scrollTop;
-  sourceHighlight.scrollLeft = source.scrollLeft;
-}
-
 function execute() {
-  project.files[project.activePath] = source.value;
+  project.files[project.activePath] = getEditorText();
  saveProject();
  const result = JSON.parse(evaluateProject(project.activePath, JSON.stringify(project.files)));
  output.textContent = result.ok ? result.output : result.error;
@ -195,13 +258,3 @@ deleteFile.addEventListener('click', () => {
  delete project.files[project.activePath];
  setActiveFile(Object.keys(project.files).sort()[0]);
 });
-source.addEventListener('input', () => {
-  project.files[project.activePath] = source.value;
-  updateHighlight();
-  syncHighlightScroll();
-  saveProject();
-});
-source.addEventListener('scroll', syncHighlightScroll);
-source.addEventListener('keydown', (event) => {
-  if ((event.metaKey || event.ctrlKey) && event.key === 'Enter') execute();
-});
--- a/site/decodal-site/src/style.css
+++ b/site/decodal-site/src/style.css
@ -419,43 +419,26 @@ button:disabled {
  text-align: left;
 }

-.editor-wrap {
+.code-editor {
  background: var(--editor-bg);
  flex: 1;
  min-height: 0;
-  position: relative;
 }

-.editor-wrap pre,
-.editor-wrap textarea {
-  border: 0;
-  box-sizing: border-box;
-  font: 14px/1.5 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
-  inset: 0;
-  margin: 0;
-  overflow: auto;
-  padding: 12px;
-  position: absolute;
-  tab-size: 2;
-  white-space: pre;
+.code-editor .cm-editor {
+  height: 100%;
 }

-.editor-wrap pre {
-  color: var(--editor-text);
-  pointer-events: none;
+.code-editor .cm-line {
+  padding: 0;
 }

-.editor-wrap textarea {
-  background: transparent;
-  caret-color: var(--editor-text);
-  color: transparent;
-  outline: none;
-  resize: none;
-  width: 100%;
+.code-editor .cm-activeLine {
+  background: rgb(59 130 246 / 0.08);
 }

-.editor-wrap textarea::selection {
-  background: var(--selection);
+.code-editor .cm-activeLineGutter {
+  background: rgb(59 130 246 / 0.12);
 }

 .output-pane pre {
--- a/site/decodal-site/src/wasm/README.md
+++ b/site/decodal-site/src/wasm/README.md
@ -20,6 +20,33 @@ Embedded hosts should depend on `decodal` and provide imports with a `SourceLoad
 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.
--- a/site/decodal-site/src/wasm/decodal_wasm_bg.wasm
+++ b/site/decodal-site/src/wasm/decodal_wasm_bg.wasm
--- a/site/decodal-site/src/wasm/package.json
+++ b/site/decodal-site/src/wasm/package.json
@ -2,7 +2,7 @@
  "name": "decodal-wasm",
  "type": "module",
  "description": "WebAssembly wrapper for evaluating Decodal in browser playgrounds.",
-  "version": "0.1.0",
+  "version": "0.1.1",
  "license": "MIT OR Apache-2.0",
  "repository": {
    "type": "git",
Author	SHA1	Message	Date
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