Adjust UP for null safety, cf. language issue #1193 #1195
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eernstg
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Sep 2, 2020
eernstg
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Sep 2, 2020
eernstg
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Sep 2, 2020
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@leafpetersen, do you have further comments on this? |
This was referenced Sep 17, 2020
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dart-lang/language#1195 changes the UP function such that it uses the greatest closure with bounded and promoted type variables, and adjusts the catch-all rules about function types (used with `Function(int)` and `String` and other "otherwise" cases). This PR adds tests for the updated rules. Change-Id: I793b85ceec76105d013c03e8d9bccdd187bb476f Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/166101 Commit-Queue: Erik Ernst <eernst@google.com> Reviewed-by: Leaf Petersen <leafp@google.com>
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As mentioned in #1193, the rules for UP involving type variables need to be adjusted for soundness. This PR makes an adjustment to achieve this (as a special case of instantiation to bound plus a check).
It also adjusts the rules for UP(
T Function<...>(...),T2) and UP(T1,T Function<...>(...)), where the current rule rule may incorrectly discard nullability.