Generate Apply instances with explicit kind arguments
#603
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After the changes in [GHC#23515](https://gitlab.haskell.org/ghc/ghc/-/issues/23515) are implemented, some `Apply` instances will fail to compile due to their left-hand sides being kind-generalized to something that is more polymorphic than what their right-hand sides will allow. For example, this commonly occurs when generating `Apply` instances for lambda-lifted definitions or declarations whose kinds use visible dependent quantification. We avoid this issue by now generating `Apply` instances with explicit kind arguments (via `TypeApplications`), leveraging the fact that we know what the kinds are (most of the time) during defunctionalization. See the new section of `Note [Defunctionalization game plan], Wrinkle 2: Non-vanilla kinds` for the full details. Resolves the "Defunctionalizing declarations using visible dependent quantification" section of #601.
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After the changes in GHC#23515 are implemented, some
Applyinstances will fail to compile due to their left-hand sides being kind-generalized to something that is more polymorphic than what their right-hand sides will allow. For example, this commonly occurs when generatingApplyinstances for lambda-lifted definitions or declarations whose kinds use visible dependent quantification.We avoid this issue by now generating
Applyinstances with explicit kind arguments (viaTypeApplications), leveraging the fact that we know what the kinds are (most of the time) during defunctionalization. See the new section ofNote [Defunctionalization game plan], Wrinkle 2: Non-vanilla kindsfor the full details.Resolves the "Defunctionalizing declarations using visible dependent quantification" section of #601.