Fix 25830 Inference of Capture-Polymorphic Lambdas v3#25905
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bracevac wants to merge 6 commits intoscala:mainfrom
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Fix 25830 Inference of Capture-Polymorphic Lambdas v3#25905bracevac wants to merge 6 commits intoscala:mainfrom
bracevac wants to merge 6 commits intoscala:mainfrom
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Originally added in scala#24560 to strip inferred retains from inlined call trees before they reach the pickler. The cc setup pipeline now handles retains correctly without this preemptive strip, and removing it leaves scala3-bootstrapped/testCompilation green.
Fixes scala#25830. Covers plain poly lambdas, curried lambdas, mixed outer/local scopes, capset type members, and bounded polymorphism (see tests/pos-custom-args/captures/i25830*).
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Superseded by #25936 |
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Fix #25830
Supersedes #25853
This changeset fixes cases where the compiler forgot capture information while inferring the type of capture-polymorphic lambdas, especially lambdas like [C^] => (x: File^{C}) => ....
The main idea is to keep capture parameters when they are part of the lambda’s actual type. At the same time, it avoids keeping ordinary local values too precisely in inferred type arguments, because that can hide real leaks.
It also teaches lambda checking to use the expected result type in more cases.
How much have you relied on LLM-based tools in this contribution?
Extensively, for fun.
How was the solution tested?
New automated tests (including the issue's reproducer, if applicable)