cvs commit: fptools/libraries/base/Data IntMap.hs Map.hs Sequence.hs Set.hs fptools/libraries/base/Data/Generics Instances.hs Twins.hs

Jim Apple japple at
Sun Jan 8 23:12:33 EST 2006

Simon Peyton Jones wrote:
> simonpj     2006/01/06 07:51:23 PST
>   Modified files:
>     libraries/base/Data  IntMap.hs Map.hs Sequence.hs Set.hs 
>     libraries/base/Data/Generics Instances.hs Twins.hs 
>   Log:
>   Eta-expand some higher-rank functions.  GHC is about to
>   move to *invariant* rather than *contra-variant* in function
>   arguments, so far as type subsumption is concerned. These
>   eta-expansions are simple, and allow type inference to
>   go through with invariance.

Why drop contra-variace?


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