-fallow-overlapping-instances Request
Ashley Yakeley
ashley@semantic.org
Sat, 18 May 2002 03:10:14 -0700
At 2002-05-17 03:54, Johannes Waldmann wrote:
>From a type-theoretic viewpoint,
>instance declarations are relations between (sets of) trees
>(= elements of the respective data types).
>So one needs representations of such relations
>with effective decidability of overlapping-ness, most-sepcific-ness and such.
Yeah but unfortunately GHC doesn't look at the contexts of instance
declarations. It has a straightforward but rather conservative concept of
"overlapping" and "most specific". I'd like to see that fixed too, but
that's a separate issue.
--
Ashley Yakeley, Seattle WA