Re: [Haskell-cafe] foreign function interface "Invalid type signature"

On 26 August 2010 10:41, Ken Takusagawa wrote:

What am I doing wrong?

module Ffi2 where { import Foreign.C.Types;

foo :: CInt -> CInt; foo x = x;

foreign export ccall foo :: CInt -> CInt;

}

Did you enable the

$ ghc -c Ffi2.hs

Ffi2.hs:8:0: Invalid type signature

You need to call it with -XForeignFunctionInterface to enable FFI methinks. -- Ivan Lazar Miljenovic Ivan.Miljenovic@gmail.com IvanMiljenovic.wordpress.com