n+k patterns

[Lennart Augustsson]

Simon Peyton-Jones wrote:

> | Hugs "demands Integral" because that's what it was told to do
> | to follow the report.  So in that sense, yes, the code
> | depends on having only one class.  But it would be easy for
> | someone to change that.
> |
> | Then again, if we're following the rules of minimal change
> | for Haskell 98, then I wouldn't have thought this was up for
> | grabs. (I'm thinking, for example, of the unnecessary "same
> | context" restriction on mutually recursive binding groups,
> | which has more practical impact, is very clearly a "bug", and
> | has not (AFAIK) been fixed in Haskell 98.  Then there's David
> | Wakeling's generalized gap proposal, and ...)
>
> That is a fair point, and is exactly the reason I bother the Haskell
> list with
> these proposals rather than simply executing them.   This is an unforced
> change, as you point out, but in fact GHC and NHC currently do one
> thing, and
> Hugs does another (i.e. follows the spec!).  So some of us have to
> change
> our implementations.

hbc is on the Integral side, if that counts. :-)
Just because ghc doesn't follow the spec isn't a good reason to change
the spec. :-)

    -- Lennart