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).
37 lines
1.7 KiB
Plaintext
37 lines
1.7 KiB
Plaintext
// Program-wide inferred-`!` union per closure shape (ERR E5.1 sub-feature 2).
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// All occurrences of `Closure(s32) -> (s32, !)` share ONE inferred error set;
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// every bare-`!` closure literal of that shape unions its raised tags in. A
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// `try slot(x)` against any matching-shape slot widens against that union — so
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// a caller whose named set covers { Negative, Other } type-checks, and the
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// error channel actually carries each closure's own tag at runtime.
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#import "modules/std.sx";
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All :: error { Negative, Other }
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// `h` is a bare-`!` Closure slot; the caller declares the union as `!All`.
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dispatch :: (h: Closure(s32) -> (s32, !), x: s32) -> (s32, !All) {
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return try h(x);
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}
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main :: () -> s32 {
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gpa := GPA.init();
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push Context.{ allocator = xx gpa } {
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// Two literals of the SAME shape raising DIFFERENT tags both feed the
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// one shared `Closure(s32)->(s32,!)` union node.
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handlers : List(Closure(s32) -> (s32, !)) = .{};
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handlers.append(closure((x: s32) -> (s32, !) { if x < 0 { raise error.Negative; } return x * 2; }));
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handlers.append(closure((x: s32) -> (s32, !) { if x == 0 { raise error.Other; } return x + 100; }));
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// success paths
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print("ok0={}\n", dispatch(handlers.items[0], 5) catch (e) 0); // 10
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print("ok1={}\n", dispatch(handlers.items[1], 7) catch (e) 0); // 107
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// failure paths: each closure raises its own tag, which propagates
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// through `try` and is absorbed by the call-site `catch` fallback
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print("err0={}\n", dispatch(handlers.items[0], -1) catch (e) -1); // raised Negative → -1
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print("err1={}\n", dispatch(handlers.items[1], 0) catch (e) -2); // raised Other → -2
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}
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return 0;
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}
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