40b5fb5f7e
Rewrite specs.md tuple/failable/pack/UFCS/grammar sections to the new syntax, update readme.md, and refresh stale tuple references in example header comments. Also fixes two pre-existing doc inaccuracies surfaced in review: drop the value-discarding `;` in the tuple-return examples, and correct the §13 function-type grammar production (optional param list + optional trailing `!` channel). Optional semantics unchanged. current/CHECKPOINT-LANG.md logs the cutover.
30 lines
1.2 KiB
Plaintext
30 lines
1.2 KiB
Plaintext
// Phase 4.2 — the canonical `Combined` struct's storage layer: a generic
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// struct whose field is a pack of PARAMETERIZED-protocol values,
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// `sources: Tuple(..VL(Ts))` → `Tuple(VL(T0), VL(T1), …)`. Each `VL(Ti)` is a real
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// 16-byte protocol value (issue: parameterized-protocol value types), and
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// `Tuple(..VL(Ts))` applies `VL` per pack element. Instantiate + whole-tuple store
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// of `xx`-erased values + per-element method dispatch all work.
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#import "modules/std.sx";
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VL :: protocol(T: Type) { get :: (self: *Self) -> T; }
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IntCell :: struct { v: i64; }
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StrCell :: struct { s: string; }
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impl VL(i64) for IntCell { get :: (self: *IntCell) -> i64 => self.v; }
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impl VL(string) for StrCell { get :: (self: *StrCell) -> string => self.s; }
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Combined :: struct($R: Type, ..$Ts: []Type) {
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sources: Tuple(..VL(Ts)); // (VL(T0), VL(T1), …) — tuple of protocol values
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value: $R;
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}
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main :: () -> i32 {
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// Combined(i64, i64, string): R=i64, Ts=[i64, string],
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// sources: (VL(i64), VL(string)).
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c : Combined(i64, i64, string) = ---;
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c.sources = .(xx IntCell.{ v = 10 }, xx StrCell.{ s = "hi" });
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c.value = 99;
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print("{} {} {}\n", c.sources.0.get(), c.sources.1.get(), c.value); // 10 hi 99
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0
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}
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