42d88a3 | plum

A statically typed, imperative programming language inspired by rust, python

42d88a3 — Peter John 2026-07-20T12:15:01+05:30

fix(plum-checker): reject a name declared as both a class and an enum variant

Files changed (2) hide show

plum-checker/src/lib.rs CHANGED Viewed

@@ -141,6 +141,18 @@ pub fn check_source(source: &ast::Source) -> CheckResult<()> {
     let (global_env, classes, methods, enum_variants) = build_global_tables(source);
     let ctx = CheckCtx { classes: &classes, methods: &methods, enum_variants: &enum_variants };
+    // A name that is both a class and an enum variant is ambiguous: `Name(...)`
+    // could mean either construction, and downstream code (both the checker's
+    // `infer_expr` and codegen) consults `enum_variants` first, so the class
+    // constructor would be silently shadowed with no diagnostic. Reject it.
+    for name in classes.keys() {
+        if enum_variants.contains_key(name) {
+            errors.push(CheckError {
+                message: format!("'{}' is declared as both a class and an enum variant", name),
+            });
+        }
+    }
     for item in &source.items {
         if let ast::Item::Fn(f) = item {
             let mut local_errors = check_fn(f, &global_env, &ctx);

plum-checker/tests/checker_tests.rs CHANGED Viewed

@@ -291,3 +291,27 @@ bad(s: Shape) -> Float =
     let result = check_source(&source);
     assert!(result.is_err());
 }
+#[test]
+fn class_name_colliding_with_enum_variant_is_a_clear_error() {
+    // `Cat(...)` is ambiguous when `Cat` is both a class and an enum variant:
+    // downstream code consults `enum_variants` first, so the class
+    // constructor would otherwise be silently shadowed with no diagnostic.
+    let src = "\
+type Cat =
+  name: Str
+enum Animal =
+  | Cat
+  | Dog
+";
+    let source = parse(src);
+    let result = check_source(&source);
+    assert!(result.is_err(), "expected Err");
+    let errs = result.unwrap_err();
+    assert!(
+        errs.iter().any(|e| e.message.contains("is declared as both a class and an enum variant")),
+        "got: {:?}",
+        errs
+    );
+}