FFI Definition

[Manuel M. T. Chakravarty]

Folks,

As promised, I have started on a definition of the Haskell
FFI.  I started by formalising those aspects of foreign
exports and imports that we have recently discussed here.
You can access the current text at

  http://www.cse.unsw.edu.au/~chak/haskell/ffi.ps.gz

In addition to general comments, I would particularly
welcome your opinion on the FIXME issues.

You may note that I have tilted the specification of the
calling convention and the related string determining the
external entity very much into the direction of the
execution platform.  In my opinion that makes the whole
description much more consistent.  In particular, we are now
talking about JVM calls rather than Java calls.  This fits
much better with ccall, wincall, and dotnet.  It also makes
it much more natural to talk about calling conventions
rather than programming languages implemented in terms of
these calling conventions.

I will add more material (including also a specification of
the FFI library) as we go.

Cheers,
Manuel