• Richard Eisenberg's avatar
    Add some commentary re: fix to #11203 · 3910d3e2
    Richard Eisenberg authored
    The fix for #11203 prohibits duplicate SigTvs in non-CUSK kind
    signatures by checking for duplicates after type inference is
    done. This works well. GHC also checks for duplicate SigTvs
    after working with partial type signatures (another place where
    SigTvs arise). However, neither fix eliminates this whole class
    of problems (because doing so would be heavier than we would
    like). So, this comment adds a warning to users of newSigTyVar
    to be aware of problems with duplicates.
TcMType.hs 66.8 KB