989e18b760
Replace the bare-paren tuple grammar with explicit, position-unambiguous
forms, mirroring how structs work:
type `(A, B)` -> `Tuple(A, B)` (named keeps `:`)
value `(a, b)` -> `.(a, b)` (named uses `=`)
typed (new) -> `Tuple(A, B).(a, b)` (like `Point.{...}`)
failable `-> (T, !)` -> `-> T !`
`-> (T1, T2, !)`-> `-> Tuple(T1, T2) !` (channel outside Tuple)
Bare `(...)` is now grouping only, everywhere; a comma in bare parens is a
hard error with a migration hint. Grouping, function types `(A, B) -> R`,
param lists, lambdas, and match bindings are unaffected.
`Tuple(...)` is strictly a TYPE in every position (including `size_of` /
`type_info` args); a tuple VALUE comes only from `.(...)` (anonymous) or
`Tuple(...).(...)` (explicitly typed). A bare `Tuple(1, 2)` is a tuple
type with non-type elements -> rejected.
The ~110 tuple-bearing corpus files were migrated with a one-shot
AST-aware migrator (the `sx migrate` tool from the prior commit, removed
here). New examples: 0130 (new syntax), 0131 (typed construction), 1060
(named-tuple failable return). 1116 golden updated for the new hint text.
34 lines
1.2 KiB
Plaintext
34 lines
1.2 KiB
Plaintext
// Phase 6 / issue 0054 — generic-struct → parameterized-protocol erasure.
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// - A generic-struct impl method `self: *Box` now resolves `self.field` to the
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// concrete INSTANCE (the template name binds to the instance type), so
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// `self.x` works (was "field not found on type 'Box'").
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// - `xx c` erases a generic-struct instance (`Combined__i64_i64`) to a
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// parameterized protocol (`VL(i64)`) via the generic
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// `impl VL($R) for Combined($R, ..$Ts)`: the thunk monomorphizes the
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// template method for the instance and dispatch works (was a trap).
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#import "modules/std.sx";
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VL :: protocol(T: Type) { get :: (self: *Self) -> T; }
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IntCell :: struct { v: i64; }
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impl VL(i64) for IntCell { get :: (self: *IntCell) -> i64 => self.v; }
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Combined :: struct($R: Type, ..$Ts: []Type) {
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sources: Tuple(..VL(Ts));
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value: $R;
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}
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impl VL($R) for Combined($R, ..$Ts) { get :: (self: *Combined) -> $R => self.value; }
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make :: (..sources: VL) -> VL(i64) {
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c : Combined(i64, ..sources.T) = ---;
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c.value = 99;
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c.sources = .(..sources);
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return xx c; // Combined__i64_i64 -> VL(i64)
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}
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main :: () -> i32 {
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r := make(IntCell.{ v = 1 });
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print("{}\n", r.get()); // 99 (dispatch through the erased Combined)
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0
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}
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