[GHC] #14461: Reuse free variable lists through nested closures

[GHC]

#14461: Reuse free variable lists through nested closures
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        Reporter:  tdammers          |                Owner:  alexbiehl
            Type:  task              |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.1
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  7258              |  Differential Rev(s):
       Wiki Page:  NestedClosures    |
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Comment (by alexbiehl):

 Replying to [comment:4 simonpj]:
 > I think that's a great plan: see [wiki:NestedClosures] under
 "Implementation".

 Ups, I didn't see that!

 I have another thing, somewhat related: If we find something like

 {{{
   case e of x {
     T a b c ->
       let [a b c] f = \[] ->
   }
 }}}

 Why not make it

 {{{
   case e of x { -- evaluate e to not change strictness
     T _ _ _ ->
       let [x] f = \[] ->
         case x of
           T a b c -> ...
   }
 }}}

 This could even be done at Core level I suppose.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14461#comment:5>
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