aa1aa63bb3
`try f()` (standalone form) now propagates a failable callee's error to the enclosing failable function. E1.4 was split: E1.4a = standalone try (failure target = function-propagation); E1.4b = fallback-target routing + failable-`or` + whole-program SCC for inferred sets + empty-inferred warning. - lowerExpr: `.try_expr` -> lowerTry - lowerTry: (1) try legal only inside a failable fn; (2) the sole failable-operand check (errorChannelOf(inferExprType(operand))); (3) named-caller widening (checkErrorSetSubset at the propagation site); (4) pure-failable lowering — condBr on tag != 0: propagate (run defers + ret the widened tag) vs continue on success - inferExprType: `.try_expr` arm (success type: void for pure-failable) - lowerBinaryOp .or_op: bail loudly on a failable LHS (exprIsFailable); the optional-`or` path is unchanged for non-failable LHS - value-carrying callee/caller `try` bail loudly (pending E2's tuple ABI) Tests: examples/221-try.sx (positive propagation, exit 5), examples/222-try-rejections.sx (3 stable rejections: outside-failable, non-failable operand, named-widening miss; exit 1). Gates: zig build, zig build test, 260/260 examples.
42 lines
1.2 KiB
Plaintext
42 lines
1.2 KiB
Plaintext
// `try` rejections (ERR step E1.4a):
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// - `try` is only valid inside a failable function,
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// - the operand must be failable (the sole failable-operand check —
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// the parser imposes none),
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// - propagating a `try` whose callee's error set is not a subset of the
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// caller's named set is rejected (widening at a function-propagation site).
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// The positive case lives in `examples/221-try.sx`.
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#import "modules/std.sx";
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A :: error { Xa }
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B :: error { Yb }
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ga :: () -> !A { return; }
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gb :: () -> !B { return; }
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plain :: () -> s32 { return 0; }
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// `try` in a non-failable function.
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bad_ctx :: () -> s32 {
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try ga(); // error: `try` outside a failable function
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return 0;
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}
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// `try` on a non-failable operand.
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bad_operand :: () -> !A {
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try plain(); // error: operand has type s32 (not failable)
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return;
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}
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// Callee's set (B = {Yb}) is not a subset of the caller's set (A = {Xa}).
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widen :: () -> !A {
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try gb(); // error: Yb not in caller's error set A
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return;
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}
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main :: () -> s32 {
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a := bad_ctx(); // force bad_ctx to lower
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b := bad_operand(); // force bad_operand to lower
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c := widen(); // force widen to lower
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return 0;
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}
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