n+k patterns

[Jon Fairbairn]

> > I argued that (Num a, Ord a) makes most sense to me.
> > You argued that (Integral a) was a conscious choice (something I
> > don't remember but I'm sure you're right), and is the right one anywa=
y.
> > =

> > I'd be interested to know what others think.  If there's any doubt,
> > we'll stay with Integral.
> =

> My view is that (n+k) patterns are evil, so it doesn't really matter
> what we decide.  :-)  No, seriously, I'm a little worried about
> widening the range of numeric types for which (n+k) patterns are
> supposed to work.  I can (just about) imagine wanting to use Rationals
> in an (n+k) pattern, but Float and Double? =


I dimly remember that the justification for having n+k was
to allow inductive definitions, which only applies to
Integral. I'd vote for keeping it as it is, too.

  J=F3n