Support $ref generation

src/json_schema.rs

@@ -247,8 +247,13 @@ where
     F: Fn(&serde_json::Value) -> Result<T, crate::error::VldError>,
 {
     fn json_schema(&self) -> Value {
-        // Nested schemas are opaque closures; emit a generic object schema.
-        serde_json::json!({"type": "object"})
+        match self.name {
+            Some(name) => serde_json::json!({
+                "$ref": format!("#/components/schemas/{}", name)
+            }),
+            // Nested schemas are opaque closures; emit a generic object schema
+            None => serde_json::json!({ "type": "object" }),
+        }
     }
 }
 

src/lib.rs

@@ -135,6 +135,20 @@ where
     schema::NestedSchema::new(f)
 }
 
+pub fn nested_named<T, F>(name: &'static str, f: F) -> schema::NestedSchema<T, F>
+where
+    F: Fn(&serde_json::Value) -> Result<T, error::VldError>,
+{
+    schema::NestedSchema::new_named(f, name)
+}
+
+#[macro_export]
+macro_rules! nested {
+    ($ty:ty) => {
+        $crate::nested_named(stringify!($ty), <$ty>::parse_value)
+    };
+}
+
 /// Create a literal value schema. Validates exact match.
 ///
 /// ```

src/schema.rs

@@ -199,6 +199,7 @@ where
     F: Fn(&Value) -> Result<T, VldError>,
 {
     parse_fn: F,
+    pub(crate) name: Option<&'static str>,
     _phantom: PhantomData<T>,
 }
 
@@ -209,6 +210,15 @@ where
     pub fn new(f: F) -> Self {
         Self {
             parse_fn: f,
+            name: None,
+            _phantom: PhantomData,
+        }
+    }
+
+    pub fn new_named(f: F, name: &'static str) -> Self {
+        Self {
+            parse_fn: f,
+            name: Some(name),
             _phantom: PhantomData,
         }
     }
@@ -219,8 +229,7 @@ where
     F: Fn(&Value) -> Result<T, VldError>,
 {
     type Output = T;
-
     fn parse_value(&self, value: &Value) -> Result<T, VldError> {
         (self.parse_fn)(value)
     }
-}
+}