[My apologies: some day - I promise - I'll learn to choose the right mailing
list... 8->]
On Mon, Oct 04, 1999 at 13:45:43 +0200, Sven Panne wrote:
[micro-marshalling]
> I know Manuel's code already and the one H/Direct produces. Has anybody
> else some FFI-related code and/or suggestions? This could be a wonderful
> topic for the wish list, but it would be nice to see the problems and needs
> for APIs different from GTK+ and OpenGL first.
Maybe it's worth to know how many objects a list has (without explicit
zeroElem), so I'd suggest to extend the class to:
marshalList :: [a] -> IO Addr
marshalListN :: Int -> [a] -> IO Addr
unmarshalList :: Addr -> IO [a]
unmarshalListN :: Int -> Addr -> IO [a]
where `marshalList' stores the list length at the beginning of the buffer,
like:
marshalList xs = do
let len = length xs
lenSize = sizeOf len
buf <- malloc (lenSize + len * sizeOf (head xs))
writeIntOffAddr buf 0 len
zipWithM_ (writeOffAddr (buf `plusAddr` lenSize)) [ 0 .. ] xs
return buf
and `instance Marshalable Int {...}'
> P.S. for the native speakers: Which spelling is correct, "marshaling" or
> "marshalling"? Ispell says "marshaling", but this looks a bit odd to me.
dictd knows both:
------------------------------------------------------------------------------
>From The Free On-line Dictionary of Computing (20Jul99) [foldoc]:
marshalling
<communications> (US -ll- or -l-) The process of packing one
or more items of data into a {message buffer}, prior to
transmitting that message buffer over a communication channel.
The packing process not only collects together values which
may be stored in non-consecutive memory locations but also
converts data of different types into a standard
representation agreed with the recipient of the message.
marshaling
<spelling> Alternative US spelling of "{marshalling}".
(1998-03-16)
------------------------------------------------------------------------------
I'd vote for the "double-L" variant... :-)
Cheers,
Michael
--
"Don't worry about people stealing your ideas. If your ideas are any
good, you'll have to ram them down people's throats."
-- Howard Aiken
