diff options
Diffstat (limited to 'compile.c')
| -rw-r--r-- | compile.c | 17 |
1 files changed, 14 insertions, 3 deletions
@@ -278,9 +278,20 @@ CORD compile_type(type_t *t) static CORD compile_lvalue(env_t *env, ast_t *ast) { if (!can_be_mutated(env, ast)) { - if (ast->tag == Index || ast->tag == FieldAccess) { - ast_t *subject = ast->tag == Index ? Match(ast, Index)->indexed : Match(ast, FieldAccess)->fielded; - code_err(subject, "This is an immutable value, you can't assign to it"); + if (ast->tag == Index) { + ast_t *subject = Match(ast, Index)->indexed; + type_t *t = get_type(env, subject); + if (t->tag == PointerType && Match(t, PointerType)->is_view) + code_err(ast, "This is a read-only view and you can't mutate its contents"); + else + code_err(subject, "This is an immutable value, you can't mutate its contents"); + } else if (ast->tag == FieldAccess) { + ast_t *subject = Match(ast, FieldAccess)->fielded; + type_t *t = get_type(env, subject); + if (t->tag == PointerType && Match(t, PointerType)->is_view) + code_err(subject, "This is a read-only view and you can't mutate its fields"); + else + code_err(subject, "This is an immutable value, you can't assign to its fields"); } else { code_err(ast, "This is a value of type %T and can't be used as an assignment target", get_type(env, ast)); } |