exception classifier functions

[Alastair Reid]

> It's unfortunate that the exception classifier functions differ
> between GHC and Hugs, even where capabilities overlap.

>     justIoErrors       :: Exception -> Maybe IOError 
>     justHugsExceptions :: Exception -> Maybe HugsException

> Would greater commonality be possible?

Yes, but it'll take a bunch of work.  The big change needed is with
the HugsExceptions which are currently little (nothing?) more than a
String.  To improve on this, we need to go through all the code that
raises exceptions and change it around.  Not hard but it'll take a
while.  And sometimes when we port a feature from another system we
find that an interface that was easy for the original system to
implement doesn't make sense as a more general interface (and, then
again, sometimes we find that it's a great design).

So, yes, it should be on the list of things to do but I don't think a
quick fix is likely to make it in before the release.

--
Alastair Reid                 alastair@reid-consulting-uk.ltd.uk  
Reid Consulting (UK) Limited  http://www.reid-consulting-uk.ltd.uk/alastair/