#11523: Infinite Loop when mixing UndecidableSuperClasses and the class/instance constraint synonym trick. -------------------------------------+------------------------------------- Reporter: ekmett | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Compiler (Type | Version: 8.0.1-rc1 checker) | Keywords: Resolution: | UndecidableSuperClasses Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: GHC rejects | Test Case: valid program | polykinds/T11523 Blocked By: | Blocking: Related Tickets: #11480 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by Iceland_jack): Replying to [comment:17 simonpj]:
Replying to [comment:16 Iceland_jack]:
Brought up on #ghc, are there technical reasons why `(,)` ''cannot'' be partially applied with the same meaning as `(&)`?
I'm lost. What is `(&)`? How is this connected with this ticket?
`(&) :: Constraint -> Constraint -> Constraint` is defined by {{{#!hs class (p, q) => p & q instance (p, q) => p & q }}} at the beginning of this ticket. This would actually be solved by #11715 (per your comment ticket:11715#comment:14)
* Allow partial applications like `(,) (Eq a) :: Constraint -> Constraint`
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11523#comment:18 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler