69aa8c3 | plum | pyrossh

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

69aa8c3 — Peter John 2026-11-01T17:14:13+05:30

fix: recovered call failures don't reposition errors; const-shaped patterns on non-enums rejected

Files changed (2) hide show

plum-checker/src/lib.rs CHANGED Viewed

@@ -2957,6 +2957,8 @@ fn checkPattern(
                 && ctx.enum_variants.contains_key(n);
             if is_known_variant {
                 Ok(()) // equality check against a known enum tag, e.g. `Red`
+            } else if n.chars().next().is_some_and(|c| c.is_uppercase()) {
+                Err(format!("'{}' is not a variant of {}", n, subject_ty))
             } else {
                 env.insert(n.clone(), TypeScheme::mono(subject_ty.clone()));
                 Ok(())
@@ -3496,7 +3498,12 @@ pub fn inferExprWith(
     if let Some(pos) = call_pos.filter(|p| p.0 != 0) {
         CUR_POS.with(|p| p.set(pos));
     }
+    let entry_err_pos = ERR_POS.with(|e| e.get());
     let r = inferExprInner(expr, env, ctx, expected);
+    if r.is_ok() {
+        // Any failure inside was recovered from; it must not mark the statement.
+        ERR_POS.with(|e| e.set(entry_err_pos));
+    }
     if r.is_err() && call_pos.is_some_and(|p| p.0 != 0) && ERR_POS.with(|e| e.get()).is_none() {
         ERR_POS.with(|e| e.set(call_pos));
     }

plum-checker/tests/checker_tests.rs CHANGED Viewed

@@ -2132,3 +2132,28 @@ fn unknown_method_on_heap_const_is_checker_error() {
     assert_eq!(assign[0].line, 13, "{:?}", assign);
     assert!(checkSrc(&src("Cfg.CELL.get()")).is_ok());
 }
+#[test]
+fn recovered_call_failure_does_not_reposition_genuine_error() {
+    let src = "enum Box[T] =\n  | Box(v: T)\n\nenum Cfg =\n  | Cfg(a: Int)\n\n  CELL = Box(1)\n\nfun f() -> Int =\n  return \"{Cfg.CELL.size()}\"\n";
+    let errs = checkSrc(src).unwrap_err();
+    let e = errs.iter().find(|e| e.message.contains("return type mismatch")).unwrap();
+    assert_eq!((e.line, e.column), (9, 1), "{:?}", errs);
+}
+#[test]
+fn const_shaped_name_pattern_on_int_is_rejected() {
+    for src in [
+        "fun f(n: Int) -> Int =\n  match n\n    MAX => 1\n    _ => 0\n",
+        "fun f(n: Int) -> Int =\n  if MAX := n\n    return 1\n  0\n",
+    ] {
+        let msg = errText(checkSrc(src));
+        assert!(msg.contains("'MAX' is not a variant of Int"), "{msg}");
+    }
+}
+#[test]
+fn digit_variant_pattern_still_works() {
+    let src = "enum V2 =\n  | A1(n: Int)\n  | B2\n\nfun f(w: V2) -> Int =\n  match w\n    A1(n) => n\n    B2 => 0\n\nfun g(w: V2) -> Int =\n  if B2 := w\n    return 1\n  0\n";
+    assert!(checkSrc(src).is_ok());
+}