213cedf0b5
The trailing-`!`-after-the-value-type spelling (`-> T !`, `-> Tuple(A,B) !`) was a
redundant second way to write a failable return that the parser folded into the
same AST as the parenthesized `(T, !)` / `(A, B, !)` result list. Remove it so
there is ONE canonical spelling: the error channel always rides as the last slot
of the parenthesized list.
- parser: `parseFnReturnType` no longer folds a trailing `!` after a value type —
it rejects it with a located diagnostic ("a failable return is written `(T, !)`
… not `T !`"). This one chokepoint covers fn declarations, lambdas, fn-pointer
types `(A) -> R`, and closure types `Closure(A) -> R`. The error-ONLY `-> !` /
`-> !ErrSet` form is unaffected (parsed by parseTypeExpr as an error_type_expr).
- migrated every usage to canonical form across library/ + examples/ + issues/ +
tests/: `-> T !E` → `-> (T, !E)`; the value-carrying `-> Tuple(A, B) !` (which
FLATTENED to a multi-value failable) → `-> (A, B, !)`, preserving behavior. A
genuine single-tuple-value failable stays `-> (Tuple(A,B), !)`.
- parser unit tests: the "bare form folds" tests become "bare form is rejected";
canonical-form parse tests retained.
- docs: specs.md §12 + scattered refs and readme.md updated to the `(T, !)` form.
Behavior-preserving (the bare form was sugar for the same AST). Adversarial review
confirmed: rejection complete across all positions, every canonical form works on
both success/error paths, error-only `-> !` intact, no crashes. Full suite green
(unit tests + 850 corpus examples).
28 lines
838 B
Plaintext
28 lines
838 B
Plaintext
// A braced `defer { … }` body parses as a full statement block (like `onfail`),
|
|
// so it supports every statement form — a destructure decl, a `catch`-statement,
|
|
// nested var decls — not just a single bare expression. Previously `defer { … }`
|
|
// routed through the expression parser and rejected those with "expected ';'".
|
|
//
|
|
// Regression (issue 0065).
|
|
|
|
#import "modules/std.sx";
|
|
|
|
E :: error { Bad }
|
|
|
|
probe :: () -> (i32, !E) { return 21; }
|
|
failing :: () -> !E { raise error.Bad; }
|
|
|
|
run :: () {
|
|
defer {
|
|
v, e := probe(); // destructure decl
|
|
if !e { print("defer: v={}\n", v); } // value live under the guard
|
|
failing() catch (x) print("defer: caught\n"); // catch-statement absorbs
|
|
}
|
|
print("body\n");
|
|
}
|
|
|
|
main :: () -> i32 {
|
|
run();
|
|
return 0;
|
|
}
|