[GHC] #11715: Constraint vs *

[GHC]

#11715: Constraint vs *
-------------------------------------+-------------------------------------
        Reporter:  bgamari           |                Owner:
            Type:  bug               |               Status:  new
        Priority:  high              |            Milestone:  8.2.1
       Component:  Compiler (Type    |              Version:  8.0.1-rc1
  checker)                           |
      Resolution:                    |             Keywords:  Typeable
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Iceland_jack):

 Replying to [comment:26 int-index]:
 > Currently, all of those types are equivalent:
 >
 > * `(a, b) => t`
 > * `(b, a) => t`
 > * `a => b => t`
 > * `b => a => t`

 Edwardk
 [https://gist.github.com/Icelandjack/5afdaa32f41adf3204ef9025d9da2a70
 #reddit-you-can-write-show-a--read-a--a---a-instead-of-show-a-read-a--a---
 a notes] that `a => b => t` is slightly weaker than `(a, b) => t` since it
 can “only reference backwards up the chain”. I can't produce an example of
 this though, there may be differences between `a => b => t` and `b => a =>
 t` as well.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11715#comment:28>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler