[GHC] #8061: Support for Complex Double in Foreign Function Interface

[GHC]

#8061: Support for Complex Double in Foreign Function Interface
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        Reporter:  dsamperi          |            Owner:
            Type:  feature request   |           Status:  new
        Priority:  normal            |        Milestone:
       Component:  Compiler          |          Version:  7.6.3
      Resolution:                    |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  None/Unknown      |       Difficulty:  Unknown
       Test Case:                    |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by simonpj):

 Sounds reasonable in principle.  Someone would need to look into the FFI
 interface, which would need to pass and return complex numbers, or perhaps
 more generally structs.  I don't have a clue what C's calling convention
 looks like for that.  I think we use `libffi` to generate code, but I'm
 pretty hazy about the details.

 Or maybe it'd be enough to return multiple ''results'', dually with
 passing multiple arguments. So at the most primitive level you could say
 {{{
 foreign import foo :: Double# -> Double# -> IO (# Double#, Double# #)
 }}}

 If someone is up for doing the legwork, I'm sure there are people on `ghc-
 devs` who can advise.

 Simon

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8061#comment:1>
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