On 2/5/07, Tony Sidaway <[EMAIL PROTECTED]> wrote:
> > Would it be best to write something to do that in C as a > foreign-primitive? Basically a C function, declared > foreign-primitive, that takes a C-pointer and an int, and allocates a > byte vector of the appropriate size. Presumably this would eat into > the nursery until such time as a minor garbage collection takes place.I suppose I mean something like this: (define produce-byte-vector (foreign-primitive scheme-object ((int size) (c-pointer data)) "C_word *p = C_alloc(sizeof(C_header)+C_align(size));C_return(C_bytevector(&p, size, data));")) I expect I've got the arithmetic wrong, but this is the basic idea. This is a nice easy implementation because you can then use (byte-vector->u8vector), (byte-vector->s16vector) or whatever you want to coerce the resulting byte vector to whatever you want.
Yes, that should work (with the caveat you mentioned: if the size of the data is large or the nursery is already used up, the latter might not be sufficiently big). An alternative is to create a suitably sized byte-vector beforehand (in Scheme, using the heap) and copying the data inside a block of foreign code (or use "move-memory!"). cheers, felix _______________________________________________ Chicken-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/chicken-users
