[Haskell-cafe] Troubles with FFI

[Donn Cave]

On Mon, 15 May 2006, Simon Peyton-Jones wrote:
> | > the automated ones, seemed to handle the case of passing numerical
> | > arrays to C, and having them get updated and passed back.  That is
> my
> | > primary interest in the FFI and yet no obvious solution or example
> | > could be found after days of internet searching and pouring over
> | > tutorials etc.
...
> ...  Indeed,
> concerning the question of passing array values between C and Haskell,
> there may be no overview or tutorial, thus far.

Or maybe it just hasn't come back from the cleaners after he poured
over it.  (ho ho ho)

Seriously, when I went looking for information on the general subject,
I think the worst problem was all the basically wrong information.
I mean, I'm sure Green Card was a great step forward, but if you're
trying to get started with FFI today, what you need to know about Green
Card is that it's dead.  Last heard from in an alpha release three years
ago, and at least for someone using GHC to do simple FFI, it's unnecessary.
But if you're at "Libraries and Tools/Interfacing other languages" on
haskell.org, there's no hint of that.  The "C" section in fact has five
such libraries, but no hint that all you really need is to read the
GHC user's guide.

	Donn Cave, donn at drizzle.com