Files
sx/examples/1055-errors-enum-value-failable-error-slot.sx
agra d8076b9333 lang: rename signed integer types sN -> iN
Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.

Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).

Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.

zig build test: 426/426; examples suite: 595/595.
2026-06-12 09:31:53 +03:00

45 lines
2.1 KiB
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// Enum-valued value-carrying failable: the SUCCESS path must zero the trailing
// error slot. Regression (issue 0097). A `-> (Enum, !E)` `return .variant`
// resolves the enum literal against the function's VALUE type (the enum), not
// the failable tuple — otherwise the literal mis-resolves (tag 0) and is stamped
// with the tuple type, which the success-return lowering mistakes for a forwarded
// full tuple and leaves the error slot UNDEFINED (read back as garbage nonzero).
//
// This pins the slot at RUNTIME on the success path (cast(i64) e, bare `if e`,
// and `e == error.X`) — not only via the `if !e` proof that the compiler can
// fold away. It also exercises a non-zero ordinal (`.blue` = 2) so a value slot
// that collapses to 0 is caught, and asserts the error PATH still carries the
// right tag and `error_tag_name`.
#import "modules/std.sx";
Color :: enum { red; green; blue; }
E :: error { Nope }
pick :: (s: string) -> (Color, !E) {
if s == "red" { return .red; }
if s == "blue" { return .blue; } // non-zero ordinal (2)
raise error.Nope;
}
main :: () -> i32 {
// ── success path: error slot MUST read 0 at runtime ──
c, e := pick("red");
print("success err int = {}\n", cast(i64) e); // 0
if e { print("bare-if e: ERROR (WRONG)\n"); } else { print("bare-if e: ok\n"); }
if e == error.Nope { print("e == Nope (WRONG)\n"); } else { print("e != Nope (ok)\n"); }
if !e { print("guard !e: c = {}\n", cast(i64) c); } // 0 (red)
// ── non-zero ordinal: value slot must carry the real ordinal ──
c2, e2 := pick("blue");
if !e2 { print("blue: err int = {}, c = {}\n", cast(i64) e2, cast(i64) c2); } // 0, 2
// ── error path: the right tag flows through ──
c3, e3 := pick("xxx");
print("error err nonzero = {}\n", cast(i64) e3 != 0); // true (ordinal is program-global, not pinned)
if e3 == error.Nope { print("error: is Nope (ok)\n"); } else { print("error: not Nope (WRONG)\n"); }
print("error tag name = {}\n", error_tag_name(e3)); // Nope
return 0;
}