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

[GHC]

#8061: Support for Complex Double in Foreign Function Interface
------------------------------------+-------------------------------------
       Reporter:  dsamperi          |             Owner:
           Type:  feature request   |            Status:  new
       Priority:  normal            |         Milestone:
      Component:  Compiler          |           Version:  7.6.3
       Keywords:                    |  Operating System:  Unknown/Multiple
   Architecture:  Unknown/Multiple  |   Type of failure:  None/Unknown
     Difficulty:  Unknown           |         Test Case:
     Blocked By:                    |          Blocking:
Related Tickets:                    |
------------------------------------+-------------------------------------
 Currently the FFI only permits BASIC return types like Double, Int, Bool,
 etc., but NOT
 Complex Double (only slightly non-basic!). This makes it impossible to
 import a Fortran
 function (not subroutine) that returns a complex value. Adding support for
 Complex Double
 would make it easier to interface to external libs like BLAS and LAPACK;
 without this
 support wrapper C libs must be used, and these are not standardized (the
 Haskell package
 hs-linear-algebra currently has some problems related to this).

 Thus adding Foreign support for Complex Double (not just through Ptr)
 would open up
 access to a large collection of external Fortran libs for the Haskell
 community. Currently
 I get the message "Unacceptable return type in FFI" when I try to return
 IO (ComplexType).

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8061>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler