Functional dependencies of some classes

snoyberg / classy-prelude

A typeclass-based Prelude.

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Functional dependencies of some classes #55

Closed sw1sh closed 11 years ago

sw1sh commented 11 years ago

Maybe dependencies not necessary in classes such as class CanPack c i | c -> i and class CanSingleton c i | c -> i? So it would be possible to also define instance CanPack ByteString Char together with already defined instance CanPack ByteString Word8. And what about adding numerical instances for Char like Num, Real and Integral so it would behave exactly like Word8?

snoyberg commented 11 years ago

Removing fundeps would make type inference almost impossible, impairing normal usage of the library.
Treating a ByteString as a sequence of characters would be encouraging bad practices. If this was really necessary, forcing the usage of a newtype wrapper would be a good thing.
I do not intend to include any orphan instances for base in classy-prelude.