On Mon, 19 Feb 2007 00:30:47 +0400, Sebastian Sylvan <[EMAIL PROTECTED]> wrote: > Well, I guess the H98 report would be a good start. But there are > multiple tutorials on type classes that will cover this, most of which > are available from haskell.org
Sebastian, I did read H98 and would like an exact reference. > > The key point is that Haskell won't guess, and in particular it won't > contradict what you tell it. I think that's the major flaw in your > reasoning, you expect Haskell to take an explicit type that you, the > programmer, supplies, and change it into something else. Why is this rule applied differently to type declarations and to instances? > In the original example you are explicitly telling Haskell that "m" is > *not* in the Monad (or any other) class. I am not telling that. I am telling that m is an instance of a class all instances of which are in the Monad class. How is this different from specifying class constraint in type declarations? David _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
