[GHC] #7671: No break spaces

[GHC]

#7671: No break spaces
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Reporter:  zenzike           |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.6.2             |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:                  
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 I thought I was going mad when the following code wasn't compiling:

 {{{
 {-# LANGUAGE UnicodeSyntax #-}
 {-# LANGUAGE RankNTypes #-}

 type F f = forall x . f x
 }}}
 GHC was producing the following error message:
 {{{
 mad.hs:4:21
     Illegal symbol '.' in type
     Perhaps you intended -XRankNTypes or similar flag
     to enable explicit-forall syntax: forall <tvs>. <type>
 }}}
 It turns out that I had somehow inserted a unicode no break space,
 character code `U+00a0`, in the line importing RankNTypes, just after the
 first `#`. Baffling.

 This begs the question: should GHC treat this unicode space as an ordinary
 space when the `UnicodeSyntax` extension is enabled? If not should there
 have been some warning that I had inserted this symbol in a language
 pragma?

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7671>
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