Malcolm Wallace
The first 2 attached patches (for base and ghc respectively) remove the Show constraint. I'm not aware of any justification for why this superclass makes sense.
I'm strongly in favour of removing the Show constraint.
The next 2 patches (for base and unix respectively) remove the Eq constraint. Here's there's some justification in the superclass, as it makes f 5 = ... work for any Num type, rather than also needing an Eq constraint,
I am undecided whether removing the Eq constraint is a good thing or not. In principle, yes, it makes perfect sense. But in practice, the example you give of pattern-matching a literal now requiring an Eq context, smells slightly wrong to me.
But pattern matching for Double or Float is a Bad Thing, so wouldn’t the solution to this be to put the EQ constraint somewhere else, such as Integral where it would be less improper? -- Jón Fairbairn Jon.Fairbairn@cl.cam.ac.uk