[Haskell-beginners] FlexibleInstances

Emanuel Koczwara poczta at emanuelkoczwara.pl
Sun Nov 24 22:24:11 UTC 2013


W dniu 24.11.2013 23:02, AntC pisze:
> Yes, you're almost there.
> You do need FlexibleInstances to be able to put [Char].
>
> To ban [a], you need to ban overlapping instances.
> {-# LANGUAGE NoOverlappingInstances #-}
>
> (Usually overlapping instances is on by default.)
>
> You're next error meesage is probably going to be,
>      Illegal overlapping instance declaration for ...
>
> Avoiding them is subtle, but a valuable discipline ;-)
>
> HTH

   Thanks, exactly what I wanted :)

Regards,
Emanuel



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