-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