From 63169394381bb8c7e7e0e9f8f134a69ccef15009 Mon Sep 17 00:00:00 2001
From: Hare <kei.hiracchi.0928@gmail.com>
Date: Tue, 16 Jun 2026 10:04:44 +0900
Subject: [PATCH] Add advanced Decodal example

---
 examples/advanced/README.md     | 22 +++++++++++++++
 examples/advanced/main.dcdl     | 47 +++++++++++++++++++++++++++++++++
 examples/advanced/profiles.dcdl | 18 +++++++++++++
 examples/advanced/schema.dcdl   | 17 ++++++++++++
 4 files changed, 104 insertions(+)
 create mode 100644 examples/advanced/README.md
 create mode 100644 examples/advanced/main.dcdl
 create mode 100644 examples/advanced/profiles.dcdl
 create mode 100644 examples/advanced/schema.dcdl

diff --git a/examples/advanced/README.md b/examples/advanced/README.md
new file mode 100644
index 0000000..3b51fae
--- /dev/null
+++ b/examples/advanced/README.md
@@ -0,0 +1,22 @@
+# Advanced Decodal example
+
+This example exercises multiple current Decodal features together:
+
+- multi-file `import`
+- top-level recursive module scope
+- schema/value composition with `&`
+- deep patch with `//`
+- `default` fallback during materialization
+- constrained function parameters
+- lazy function arguments
+- `match` expressions
+- nested dot-path fields
+- arrays
+
+Run it with:
+
+```sh
+cargo run -q -p decodal -- examples/advanced/main.dcdl
+```
+
+The entrypoint is `main.dcdl`.
diff --git a/examples/advanced/main.dcdl b/examples/advanced/main.dcdl
new file mode 100644
index 0000000..0df7cc4
--- /dev/null
+++ b/examples/advanced/main.dcdl
@@ -0,0 +1,47 @@
+let
+  schema = import "./schema.dcdl";
+  profiles = import "./profiles.dcdl";
+
+  mkService = (cfg: schema.Service) =>
+    cfg // {
+      summary = match cfg.env {
+        "prod": "production service";
+        "dev": "development service";
+        _: "custom service";
+      };
+    };
+
+  devService = mkService(
+    profiles.base & {
+      name = "api-dev";
+      port = 8443;
+    }
+  );
+
+  prodService = mkService(
+    profiles.prod & {
+      name = "api";
+      port = 9443;
+    }
+  );
+
+  disabledService = mkService(
+    profiles.disabled & {
+      name = "api-disabled";
+      port = 10443;
+    }
+  );
+in
+{
+  services = [
+    devService,
+    prodService,
+    disabledService,
+  ];
+
+  selected = match "prod" {
+    "prod": prodService;
+    "dev": devService;
+    _: disabledService;
+  };
+}
diff --git a/examples/advanced/profiles.dcdl b/examples/advanced/profiles.dcdl
new file mode 100644
index 0000000..d011f18
--- /dev/null
+++ b/examples/advanced/profiles.dcdl
@@ -0,0 +1,18 @@
+# Environment-specific patches.
+
+base = {
+  env = "dev";
+  tags = ["decodal", "dev"];
+};
+
+prod = base // {
+  env = "prod";
+  host = "api.internal";
+  feature.limit = 100;
+  tags = ["decodal", "prod"];
+};
+
+disabled = base // {
+  feature.enable = false;
+  tags = ["decodal", "disabled"];
+};
diff --git a/examples/advanced/schema.dcdl b/examples/advanced/schema.dcdl
new file mode 100644
index 0000000..9b51dc8
--- /dev/null
+++ b/examples/advanced/schema.dcdl
@@ -0,0 +1,17 @@
+# Shared service schema.
+# Top-level fields are recursive, so SecurePort can refer to Port.
+
+Port = Int & >= 1 & <= 65535;
+SecurePort = Port & > 443;
+
+Service = {
+  name = String;
+  env = String default "dev";
+  host = String default "localhost";
+  port = SecurePort default 8443;
+
+  feature = {
+    enable = Bool default true;
+    limit = Int & >= 0 default 10;
+  };
+};