[GHC] #4061: Implement mutually recursive view patterns

[GHC]

#4061: Implement mutually recursive view patterns
-------------------------------------+------------------------------------
        Reporter:  batterseapower    |            Owner:
            Type:  feature request   |           Status:  closed
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  6.13
      Resolution:  wontfix           |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
-------------------------------------+------------------------------------
Changes (by rwbarton):

 * difficulty:   => Unknown


Comment:

 BTW, since the view patterns in your example are not mutually recursive,
 you can use this hack to break up the top level scope:
 {{{
 {-# LANGUAGE ViewPatterns, TemplateHaskell #-}
 module RecursiveViewPatterns where

 (foo, unzip -> (bars, bazs)) = undefined
 [d||]    -- or  return []
 (spqr, ($ foo) -> metavariable) = undefined
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/4061#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler