fundeps help

Simon Peyton-Jones simonpj at
Tue Dec 4 03:27:15 EST 2007

| > And here we know that y=Bool; yet since we don't write the type sig
| > directly we can't say it.  So GHC's implementation of fundeps rejects
| > this program; again it can't be translated into System F.
| Conveniently, this is a good example of my other problem with fundeps :-)
| I can work around the problem from my first email with an unsafeCoerce,
| but is there any way I can get around the issue above at the moment in
| either 6.8 or the HEAD? I actually plan to recast the code in question
| using associated type synomyms once they're working properly, but would
| like to be able to make some progress now.

I think that if you use the HEAD, much of this will work, if you use the type-equality notation.  But you will probably encounter bugs too.  And in so doing, and reporting them, you'll be doing us a service.


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