[GHC] #9872: Runing type functions is too slow

[GHC]

#9872: Runing type functions is too slow
-------------------------------------+-------------------------------------
              Reporter:  simonpj     |            Owner:
                  Type:  bug         |           Status:  closed
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:  fixed       |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:              |       Blocked By:
  None/Unknown                       |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
-------------------------------------+-------------------------------------

Comment (by goldfire):

 I don't have anything in particular in mind -- just that we happen to have
 some expertise on taking a functional program and executing it quickly,
 and perhaps we can apply that knowledge to this problem. It seems to me
 that the algorithm used to reduce type families evolved out of a
 constraint-solving process, and taking a more direct tack might prove
 fruitful, while still retaining the ability to work with programs where
 bits (skolem type variables) aren't -- and can't be -- known.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9872#comment:31>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler