Produce coercion rules for derived Functor instances
I don't think we do this yet, but I think we probably can. If we derive a Functor
instance, we should, whenever possible and valid, produce some sort of fmap coerce = coerce
rule for that type. This is done manually for lists in GHC.Base
, but I imagine it probably applies (much) more generally.
Trac metadata
Trac field | Value |
---|---|
Version | 7.9 |
Type | FeatureRequest |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler |
Test case | |
Differential revisions | |
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Blocking | |
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Operating system | |
Architecture |