[GHC] #12626: Remove redundant type applications in Core

[GHC]

#12626: Remove redundant type applications in Core
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        Reporter:  nomeata           |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.0.1
      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 nomeata):

 How is this idea different from the System IF?
  * Conceptually, I am not trying to change core, but rather change the in-
 memory representation of Core. All the theory and reasoning about Core is
 untouched! Using a pattern synonym makes that very explicit. (Some
 operations, e.g. simple traversals, will be happy to work on the raw
 representation, but that’s just an optimization of the code).
  * System IF tries to handle one non-type-argument at a time, while my
 code always compresses a whole chain of arguments:

    ||=Core=||`(,) @Bool @Int True 1`||`(,) @Bool @Int True`||
    ||=SystemIF=||`((,) True) 1`||`((,) True) @Int`||
    ||=This idea=||`(,) [True, 1]`||`(,) [@Int, True]`||

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12626#comment:2>
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