[GHC] #1087: Bang pattern parsing with infix ops

[GHC]

#1087: Bang pattern parsing with infix ops
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    Reporter:  dons               |       Owner:               
        Type:  bug                |      Status:  new          
    Priority:  normal             |   Milestone:               
   Component:  Compiler (Parser)  |     Version:  6.6          
    Severity:  normal             |    Keywords:  bang patterns
  Difficulty:  Easy (1 hr)        |    Testcase:               
Architecture:  Unknown            |          Os:  Unknown      
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{{{
     $ ghci -fbang-patterns

 -- Ok

     Prelude> let at a !b = False in at 1 2
     False

     Prelude> let (.!.) a !b = False in 1 .!. 2
     False

 -- ~ patterns are ok

     Prelude> let a `at` ~b = False in at 1 2
     False

     Prelude> let a .!. ~b = False in 1 .!. 2
     False

     Prelude> let ~a .!. b = False in 1 .!. 2
     False

 -- Parse error if we combine bang patterns with infix decls:

     Prelude> let a .!. !b = False in 1 .!. 2
     <interactive>:1:10: parse error on input `!'

     Prelude> let a `at` !b = False in at 1 2
     <interactive>:1:11: parse error on input `!'

     Prelude> let !a .!. b = False in 1 .!. 2
     <interactive>:1:5: Parse error in pattern

 }}}

 So looks like ops and infix declarations are missing a case for bang
 patterns.

 -- Don

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/1087>
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