3805a051cc
type_info($T) is still unimplemented, so the round-trip
define(declare("ShapeCopy"), type_info(Shape)) bails with
"type_info is not yet implemented" plus the downstream
enum-inference cascade. Snapshot pins that current behavior;
the next commit implements type_info and turns this green.
35 lines
1.1 KiB
Plaintext
35 lines
1.1 KiB
Plaintext
// Comptime reflection — `type_info($T)`: reflect a SOURCE enum INTO a `TypeInfo`
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// value, then feed that value straight back to `define` to mint a byte-identical
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// copy. This is the inverse of `define`'s decode: `type_info` reads a type's
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// variants (name + payload type) out of the type table and constructs the same
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// `.enum(EnumInfo{ variants })` value the `define` examples write by hand.
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//
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// Round-trip: `ShapeCopy` is reconstructed purely from `type_info(Shape)` — no
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// literal variant list — and constructs/matches like the original.
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#import "modules/std.sx";
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#import "modules/std/meta.sx";
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Shape :: enum {
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circle: f64;
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rect: i64;
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empty;
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}
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// Reflect Shape → TypeInfo, then reconstruct an identical nominal enum.
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ShapeCopy :: define(declare("ShapeCopy"), type_info(Shape));
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describe :: (s: ShapeCopy) {
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if s == {
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case .circle: (r) { print("circle r={}\n", r); }
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case .rect: (n) { print("rect n={}\n", n); }
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case .empty: { print("empty\n"); }
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}
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}
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main :: () -> i32 {
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describe(.circle(2.5));
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describe(.rect(7));
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describe(.empty);
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return 0;
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}
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