[GHC] #4359: Implement lambda-case/lambda-if

[GHC]

#4359: Implement lambda-case/lambda-if
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  Reporter:  batterseapower    |          Owner:                  
      Type:  feature request   |         Status:  new             
  Priority:  normal            |      Milestone:  7.6.1           
 Component:  Compiler          |        Version:  7.1             
Resolution:                    |       Keywords:                  
        Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
   Failure:  None/Unknown      |     Difficulty:  Unknown         
  Testcase:                    |      Blockedby:                  
  Blocking:                    |        Related:                  
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Comment(by simonmar):

 Replying to [comment:74 mikhail.vorozhtsov]:

 > How to implement (4)?

 In Alex, `()` matches the empty string.  So you want something like

 {{{
 <after_lam>
   @varid    { check_for_case }
   ()        { pop the after_lam state and call lexToken }
 }}}

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4359#comment:76>
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