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.
26 lines
910 B
Plaintext
26 lines
910 B
Plaintext
// Failable `or` value-terminator (ERR step E2.4a). `lhs or value` where `lhs`
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// is a value-carrying failable (`-> (T, !E)`): on success the result is the
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// LHS value; on failure the LHS error is discarded and the result is the
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// terminator value. The whole expression is non-failable (type T). The chain
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// form (`try a or try b`) needs fallback-target routing and lands in E2.4b.
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// Rejections: `examples/232-failable-or-reject.sx`.
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#import "modules/std.sx";
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E :: error { Bad, Empty }
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parse :: (n: i32) -> i32 !E {
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if n < 0 { raise error.Bad; }
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if n == 0 { raise error.Empty; }
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return n * 2;
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}
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main :: () -> i32 {
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a := parse(5) or 0; // success → 10
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b := parse(-1) or 99; // Bad → 99 (terminator)
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c := parse(0) or 7; // Empty → 7 (terminator)
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r := a + b + c; // 10 + 99 + 7 = 116
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print("or result: {}\n", r);
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return r;
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}
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