Files
sx/examples/0187-types-enum-qualified-variant.sx
agra 9e3aabcf76 comptime VM: Phase 3 — register_type write side + payloadless-enum fixes
The mutating compiler-API, minting types LAZILY at lowering time (single pass,
the existing runComptimeTypeFunc path — so the write side is legacy-only; the
VM isn't wired at lowering time, and the read-side readers stay dual-path):

  declare_type(name) -> Type            forward nominal handle (≈ declare)
  pointer_to(t) -> Type                 build *T references
  register_type(handle, kind, members)  ONE kind-branching fill (≈ unified define)

register_type branches on kind IN THE COMPILER (subsuming define's per-kind
dispatch); codes match type_kind: 1 struct, 2 actual .@"enum", 3 tagged_union,
4 tuple. Members are {name: string, ty: Type}. A non-generic `-> Type` builder is
now flagged is_comptime (decl.zig) so its dead body permits the welded calls.

Graph support: forward declare_type handles + pointer_to express a mutually-
recursive A<->B graph (*A, *B, B-by-value) before bodies are filled. register_type
is idempotent — re-filling a nominal slot (a minting module reached via two import
edges) re-mints identically rather than erroring (nominalIdent reads identity from
any nominal kind).

Fixes (issue 0142):
- A fully payloadless comptime-minted enum was minted as an all-void tagged_union,
  whose IR size disagrees with its LLVM size -> verifySizes panic. Now mints a real
  .@"enum" (register_type kind 2 AND the metatype defineEnum).
- Bare `EnumType.variant` qualified construction of a payloadless variant wasn't
  supported (failed for hand-written enums too — the type name lowered to a Type
  value). Added in lowerFieldAccess via isPayloadlessVariant; payload-carrying
  variants keep their call form.

Examples: 0631 (graph + actual enum + reflection), 0632 (make_enum all-void),
0633/0634/0635 (namespaced / bare / multi-edge import of a minted type), 0187
(qualified variant construction). Unit tests added.

Parity 697/697 (gate OFF and -Dcomptime-flat).
2026-06-18 10:47:36 +03:00

36 lines
1.0 KiB
Plaintext

// Qualified enum-variant construction: `EnumType.variant` for a payloadless
// variant, the explicit twin of the leading-dot `.variant` form. Works for a
// plain enum and for a payloadless variant of a tagged union; a payload-carrying
// variant keeps its call form (`Shape.circle(2.0)`), unaffected.
#import "modules/std.sx";
Color :: enum { red; green; blue; }
Shape :: enum {
circle: f32; // payload-carrying
dot; // payloadless
}
main :: () {
// Plain enum, qualified construction.
c := Color.green;
if c == {
case .red: { print("red\n"); }
case .green: { print("green\n"); }
case .blue: { print("blue\n"); }
}
// Tagged union: payloadless variant qualified, payload variant via call.
d := Shape.dot;
if d == {
case .circle: (r) { print("circle {}\n", r); }
case .dot: { print("dot\n"); }
}
s := Shape.circle(2.0);
if s == {
case .circle: (r) { print("circle {}\n", r); }
case .dot: { print("dot\n"); }
}
}