[GHC] #9173: Better type error messages

[GHC]

#9173: Better type error messages
-------------------------------------+------------------------------------
        Reporter:  simonpj           |            Owner:
            Type:  bug               |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.8.2
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
-------------------------------------+------------------------------------

Comment (by nomeata):

 Despite the very general ticket title, let’s not confalte multiple errors.
 The original ticket was a about a type mismatch (inferred vs. expected).
 The example by schlyer is about an ambiguous type in the GHCi prompt. Note
 that with some more instances added, `map 1 [1..5]` would type check!

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9173#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler