72731f97ee
A `spread_expr` element inside a tuple literal now expands the pack into the tuple's fields: `(..xs.get)` ≈ `(xs[0].get(), …, xs[N-1].get())` (Decision 2 — a pack is stored by materializing a tuple). lowerTupleLiteral detects a pack-spread element via packSpreadRefs and splices the per-element Refs as fields (typed via getRefType); for Box(T) the materialized tuple is heterogeneous. A spread whose operand isn't a pack falls through to the existing spread_expr diagnostic (tuple-value spread not yet handled). When any element is a spread, field-count ≠ element-count, so the contextual target-tuple alignment is skipped (field types inferred from the expanded refs). examples/198-pack-tuple-materialize.sx.
26 lines
939 B
Plaintext
26 lines
939 B
Plaintext
// Feature 1 — materialize a tuple from a pack via `(..xs.method)` (Decision 2:
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// a pack is stored by materializing a tuple). `(..xs.get)` projects `get` over
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// the pack and collects the results into a real tuple value, which can then be
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// stored, indexed, and (for `Box(T)`) is heterogeneous per position.
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#import "modules/std.sx";
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Box :: protocol(T: Type) {
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get :: () -> T;
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}
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IntCell :: struct { v: s64; }
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StrCell :: struct { s: string; }
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impl Box(s64) for IntCell { get :: (self: *IntCell) -> s64 => self.v; }
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impl Box(string) for StrCell { get :: (self: *StrCell) -> string => self.s; }
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snapshot :: (..xs: Box) -> void {
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t := (..xs.get); // tuple (s64, string) materialized from the pack
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print("0={} 1={}\n", t.0, t.1);
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}
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main :: () -> s32 {
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snapshot(IntCell.{ v = 42 }, StrCell.{ s = "hi" });
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snapshot(StrCell.{ s = "x" }, IntCell.{ v = 7 }); // order swapped → (string, s64)
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0;
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}
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