Exceptions

[Bulat Ziganshin]

Hello Simon,

Friday, September 1, 2006, 5:05:42 PM, you wrote:

>>> I don't think we need more extensions to do a reasonable job of
>>> extensible exceptions:
>> 
>>> http://www.haskell.org/~simonmar/papers/ext-exceptions.pdf

>> it can be used with ghc 6.4, or 6.6, or ...? some solution in this
>> area, imho, is a must for serious application development

> I didn't want to unilaterally implement something without having a
> discussion about exactly what to do, as there are various design issues.
> The Haskell Workshop paper advocates one particular point in the design
> space, and I think the point it occupies is a local maximum for various
> reasons, but it's not 100% clear that this is the right thing for
> Haskell'.

but afai understood your idea don't require language changes? so it
can be implemented as some library that can be used with 6.4, 6.6 and
other ghc versions?

moreover, although i don't yet read papers, i guess that
extensible extensions can be implemented in the same way over any
extensible/dynamic types. so imho your discussion don't make much
sense - exceptions is just one of applications of such types and at
current stage can be implemented only over Dynamic. when open types
will be added to Haskell, they should be used for all current
applications of Dynamic, including these exceptions


-- 
Best regards,
 Bulat                            mailto:Bulat.Ziganshin at gmail.com