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).
41 lines
1.3 KiB
Plaintext
41 lines
1.3 KiB
Plaintext
// Backtick raw identifier as the error-tag binding of `catch` and `onfail`. A
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// reserved type-name spelling (`s2`, `u8`) is a value name when backticked, so
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// it is accepted as the tag binding and a later reference resolves to it. A
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// *bare* reserved spelling in the same position is still rejected (see
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// examples/1123), so the backtick escape is the only way to spell these tags.
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// Regression (issue 0089 — attempt-2 catch/onfail coverage).
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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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// `catch` tag binding spelled `s2`, referenced in the match body.
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classify :: (n: s32) -> s32 {
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return parse(n) catch (`s2) == {
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case .Bad: 1;
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case .Empty: 2;
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else: 3
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};
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}
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// `onfail` tag binding spelled `u8`, referenced in the cleanup body.
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cleanup :: (n: s32) -> !E {
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onfail (`u8) { if `u8 == error.Bad { print("cleanup: bad\n"); } }
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if n < 0 { raise error.Bad; }
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return;
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}
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main :: () -> s32 {
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print("classify(-1) = {}\n", classify(-1));
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print("classify(0) = {}\n", classify(0));
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print("classify(5) = {}\n", classify(5));
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c := cleanup(-1);
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print("done\n");
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return 0;
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}
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