Avoid kind-projector syntax with variance annotations #3207
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Also /cc @djspiewak. |
Codecov Report
@@ Coverage Diff @@
## master #3207 +/- ##
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Coverage 93.05% 93.05%
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Files 376 376
Lines 7412 7412
Branches 192 192
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Hits 6897 6897
Misses 515 515
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LukaJCB
approved these changes
Dec 13, 2019
joroKr21
approved these changes
Dec 13, 2019
kailuowang
approved these changes
Dec 13, 2019
djspiewak
approved these changes
Dec 13, 2019
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This is definitely one of the corners of kind-projector that I don't care for at all. Also it has some weird caveats to it such that, in general, when you need variance or bounds or things, you usually end up being explicit with a type alias anyway. So I'm in favor of this change unambiguously.
This was referenced Dec 13, 2019
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Dotty currently reserves
*for use as a type lambda placeholder for compatibility with kind-projector's syntax on Scala 2, via a currently-unimplemented-Ykind-projectorcompiler option. It's not clear whether-Ykind-projectorshould or will support kind-projector'sλ[`-α` => Whatever[α]]syntax, or even-*. (I'm working on implementing-Ykind-projectorat the moment, and personally I don't see compatibility with the goofier corners of kind-projector's syntax as a priority.)Cats only uses kind-projector's variance annotations in this one file, and they're pretty easy to replace, and in my view the vanilla Scala syntax is clearer, anyway.
/cc @smarter