[GHC] #9732: Pattern synonyms and unboxed values

[GHC]

#9732: Pattern synonyms and unboxed values
-------------------------------------+-------------------------------------
              Reporter:  monoidal    |            Owner:  cactus
                  Type:  bug         |           Status:  new
              Priority:  normal      |        Milestone:
             Component:  Compiler    |          Version:  7.8.3
            Resolution:              |         Keywords:
      Operating System:              |     Architecture:  Unknown/Multiple
  Unknown/Multiple                   |       Difficulty:  Unknown
       Type of failure:  Compile-    |       Blocked By:
  time crash                         |  Related Tickets:
             Test Case:              |
              Blocking:              |
Differential Revisions:              |
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Comment (by cactus):

 Never mind, I've figured out that last bit -- it's because in this case,
 `$mPAT` is used at type `Int# -> Int# -> Int# -> Int#`, so it's always
 going to be strict in both the `cont` and the `fail` arguments.

 I'll change the code generator for matchers so that both `cont` and `fail`
 takes an extra `()` argument. Another problem, then, will be making the
 matcher polymorphic enough that its `r` type argument can be either `*` or
 `#`...

 So all in all, in this example, currently:

 {{{
 $mPAT :: forall (r :: *). Int# -> r -> r -> r
 }}}

 but it should be

 {{{
 $mPAT :: forall (r :: ?). Int# -> (() -> r) -> (() -> r) -> r
 }}}

 Does that sound reasonable?

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/9732#comment:10>
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