Derive constructor signatures from types

Author: olwang

README.md

@@ -15,6 +15,7 @@ It currently implements:
 - Lexer, lightweight parser, syntax AST, HIR signature table, and semantic checks for the review-critical v0.4.1 rules
 - Builtin signatures for the current fixture stdlib surface, including `Image`, `File`, `Map`, `ResourcePool`, `Json`, `Csv`, database/resource helpers, and cache/config helpers
 - HIR type and field tables for class/struct/resource declarations and handle fields
+- HIR constructor signatures derived from declared type fields
 - AST-driven mode and call checks for local-only features, named arguments, data effects, and retaining APIs
 - AST-driven body checks for local moves, early-exit-aware `fresh` returns, resource escape, resolved handle-field `take`, and managed closure captures
 - Focused check modules for mode, calls, body semantics, and forbidden operator behavior

src/hir.rs

@@ -118,13 +118,15 @@ impl Hir {
     }
 
     fn insert_type(&mut self, type_info: TypeInfo) {
+        let constructor = constructor_sig_from_type(&type_info);
         for field in type_info.fields.values() {
             self.fields_by_name
                 .entry(field.name.clone())
                 .or_default()
                 .push(field.clone());
         }
         self.types.insert(type_info.name.clone(), type_info);
+        self.insert_function(constructor);
     }
 
     fn insert_builtins(&mut self) {
@@ -197,6 +199,28 @@ fn field_info_from_decl(field: &FieldDecl) -> FieldInfo {
     }
 }
 
+fn constructor_sig_from_type(type_info: &TypeInfo) -> FunctionSig {
+    let mut fields: Vec<&FieldInfo> = type_info.fields.values().collect();
+    fields.sort_by(|left, right| left.name.cmp(&right.name));
+
+    FunctionSig {
+        namespace: None,
+        name: type_info.name.clone(),
+        params: fields
+            .into_iter()
+            .map(|field| ParamSig {
+                name: field.name.clone(),
+                effect: None,
+                type_name: field.type_name.clone(),
+            })
+            .collect(),
+        return_type: Some(type_info.name.clone()),
+        returns_fresh: true,
+        retained_params: HashSet::new(),
+        is_builtin: false,
+    }
+}
+
 fn qualified_key(namespace: &str, name: &str) -> String {
     format!("{namespace}.{name}")
 }

tests/fixtures/fail/constructor-field-arguments.rss

@@ -0,0 +1,11 @@
+// expect: RS0203 RS0204
+mode: managed
+
+struct Response {
+    status: Int
+    body: String
+}
+
+fn bad_response(body: read String) -> Result<fresh Response, HttpError> {
+    return Response(status: 200, boody: read body)
+}