83ec2536af
try foo() catch (e) { } // legal
try foo() catch e { } // parse error with a migration hint
Same capture style as the for-loop. All four catch shapes keep working
with the parenthesized binding — block, bare-expression body, and the
== match sugar — and the no-binding forms are unchanged. onfail follows
the same rule (onfail (e) { }); its expression-cleanup form is
disambiguated by the paren-group-before-brace lookahead, so
onfail (f()); stays an expression cleanup.
AST unchanged; the printer renders the parens; the #run escape help
text updated. Corpus migrated (57 catch + 3 onfail bindings, in-source
parser test strings, specs incl. grammar rules, readme untouched —
no catch examples there).
Regression: examples/1157-diagnostics-catch-binding-needs-parens.sx;
re-captured stderr for 1010/1013/1037/1123 (migrated source echoed in
carets + help text).
32 lines
984 B
Plaintext
32 lines
984 B
Plaintext
// Comptime `#run` of a failable composes with the handlers exactly as at
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// runtime: `catch` absorbs, `or` terminates, a successful bare `#run` yields the
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// value (error channel stripped), and an `onfail` in the evaluated body still
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// runs during comptime unwinding (E5.2).
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#import "modules/std.sx";
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E :: error { Bad, Empty }
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parse :: (n: s32) -> (s32, !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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guard :: (ok: bool) -> !E {
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onfail print("comptime cleanup\n");
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if !ok { raise error.Bad; }
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return;
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}
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ok_v :: #run parse(5); // success → 10 (value, error stripped)
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caught :: #run parse(-1) catch (e) 99; // Bad → 99
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ored :: #run parse(0) or 55; // Empty → 55
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#run guard(false) catch (e) { }; // onfail fires during the comptime unwind
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main :: () -> s32 {
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print("ok={} caught={} ored={}\n", ok_v, caught, ored);
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return ok_v + caught + ored; // 10 + 99 + 55 = 164
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}
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