[GHC] #12618: Add saturated constructor applications to Core

[GHC]

#12618: Add saturated constructor applications to Core
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        Reporter:  simonpj           |                Owner:  nomeata
            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):

 Well, the whole point of this ticket is to have `ConApp` as soon as
 possible, and nesting tuples with `$W(,)` will have again the quadratic
 cost until we get rid of them, so I am not convinced. Also it feels wrong
 to fight against the inliner here…

 Would it be wrong for GHC to look a that rule, notice that something
 marked as `INLINE` occurs on the LHS, but then notice that it is used
 unsaturated, hence conclude that it will not have been inlined in the
 program where the rule needs to be matched, and omit the warning?

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12618#comment:27>
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