[GHC] #8325: Pattern guards in anonymous functions

GHC ghc-devs at haskell.org
Sat Jan 23 18:32:05 UTC 2016


#8325: Pattern guards in anonymous functions
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        Reporter:  mcollis           |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  7.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by rwbarton):

 One tricky case would be trying to write something like
 {{{
 f z
   | odd z = \x y | x > y -> x
                  | otherwise -> y
   | even z = \x y -> 0
 }}}
 The `| even z` guard has to be attached to `f` because it is followed by
 `=`, but that requires some look-ahead.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8325#comment:1>
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