> Hi all. Was there ever any sort of consensus about whether pattern
> guards ought to be "nestable", or not?
>
> And if not, was there some semantic objection to this, was the syntax
> just considered to Unspeakable to be spoken of, or is the feature
> just largely redundant? (I think you can always rewrite them to flat
> p-g's, without mammoth pain.)
No semantic objection, but GHC doesn't implement them because of
the lack of a decent syntax. The beauty of flat pattern guards is
that they have the same syntax as qualifiers in list comprehensions.
Simon
