donn:
On Mon, 13 Nov 2006, Donald Bruce Stewart wrote:
And for custom data (not just C strings), if the withCString* functions don't quite fit, you can always pack the foreign Ptr into a ByteString by stepping inside the ByteString constructor:
That's actually what I tried first, but in this particular situation (ghc-6.4.1 / fps-0.7), PS apparently isn't exported?
Right, you'll want to grab the soon-to-be-tagged fps 0.8, which matches that provided with ghc 6.6. It's in the darcs repo.
The CStringLen approach works, except that the allocated data doesn't get garbage-collected. Just for the sake of experiment I tried a regular CString with packMallocCString, and that didn't leak nearly as much memory - but still some, in a simple loop where "pack" doesn't leak anything.
-- Don