[Haskell-cafe] Docs on the current and future constraint solver?

[Corey O'Connor]

I believe I have run headlong into issue #3064 in ghc
(http://hackage.haskell.org/trac/ghc/ticket/3064). All I think I know
is this:
* this is a performance issue with the system used to solve type constraints.
* the solver is undergoing an overhaul to resolve performance issues
in addition to other issues.
* An efficient constraint solver is difficult. NP-Complete in the general case?

Beyond that I'm at a loss. What can I read to understand the
constraint satisfaction problem as it stands in GHC? Is there a paper
on the implementation of the current solver? Anything on how the new
solver will differ from the current?

I think I located one page on the new solver:
http://hackage.haskell.org/trac/ghc/wiki/TypeFunctionsSolving

Cheers,
Corey O'Connor