[Haskell-cafe] Simple type-class experiment turns out not so simple...

[Christoph Breitkopf]

On Sun, Jan 8, 2012 at 9:25 PM, Brent Yorgey <byorgey at seas.upenn.edu> wrote:

> On Fri, Jan 06, 2012 at 10:51:58AM +0000, Steve Horne wrote:
> >
> > If I specify both extensions (-XMultiParamTypeClasses and
> > -XFlexibleInstances) it seems to work, but needing two language
> > extensions is a pretty strong hint that I'm doing it the wrong way.
>
> Not necessarily.  These two extensions in particular (and especially
> the second) are quite uncontroversial.
>

I really don't know much about the subject, but

http://hackage.haskell.org/trac/haskell-prime/wiki/MultiParamTypeClassesDilemma

does not sound "uncontroversial" to me. That's why I avoided them so far.

- Chris
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