Detect case where two alternatives are the same after widening ExprTypes #18787
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In implicit or extension method search we might get two alternatives that are different but that point to the same singleton type after widening ExprTypes. In that case we can arbitrarily pick one of them instead of declaring an ambiguity. Fixes scala#18768
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TY for the fix 🙏 |
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@benhutchison You are very welcome! The good minimization helped a lot. |
dwijnand
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Oct 30, 2023
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dwijnand
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dwijnand
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LGTM, just some performance questions. Shall we run benchmarks seeing as we're adding the usage of =:= and widening to what was originally just int and boolean comparison?
| if (winsType2) 0 else 1 | ||
| if winsType1 && winsType2 | ||
| && alt1.widenExpr =:= alt2.widenExpr | ||
| && alt1.widenExpr.isStable |
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Check is isStable first, for performance?
odersky
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Oct 30, 2023
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I think with the swap in conditions you suggested there are no worries about performance anymore. Merging |
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In implicit or extension method search we might get two alternatives that are different but that point to the same singleton type after widening ExprTypes. In that case we can arbitrarily pick one of them instead of declaring an ambiguity.
Fixes #18768