[GHC] #8137: Permited mega-polymorphic type

[GHC]

#8137: Permited  mega-polymorphic type
------------------------------------------------+--------------------------
        Reporter:  wvv                          |            Owner:
            Type:  bug                          |           Status:  closed
        Priority:  normal                       |        Milestone:
       Component:  Compiler (Type checker)      |          Version:  7.6.3
      Resolution:  invalid                      |         Keywords:
Operating System:  Unknown/Multiple             |     Architecture:
 Type of failure:  GHC accepts invalid program  |  Unknown/Multiple
       Test Case:                               |       Difficulty:
        Blocking:                               |  Unknown
                                                |       Blocked By:
                                                |  Related Tickets:
------------------------------------------------+--------------------------

Comment (by wvv):

 May be I misunderstood, it looks like this case is a part of 'infinite
 type':
 {{{
 > let u x = (x,u)

 <interactive>:33:14:
     Occurs check: cannot construct the infinite type:
       t1 = t0 -> (t0, t1)
     In the expression: u
     In the expression: (x, u)
     In an equation for `u': u x = (x, u)
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8137#comment:2>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler