Ah, yeah. That was an alternative I was considering, though I wasn't sure how to get the size of nativeint -- now I see: sizeof(value)! :)
Still not the ideal, but probably a little nicer than using 'hash' to reveal abstracted values. ;) BTW, thank-you Florent, for your articles on interfacing with C... I know I've referenced them a few times. On Thu, Apr 5, 2012 at 11:20 AM, Florent Monnier <monnier.flor...@gmail.com>wrote: > Le jeudi 05 avril 2012 07:57:45, Anthony Tavener a écrit : > > I'm trying to determine the size of a Bigarray, in bytes. > > > > I've tried several things... ending up with this as the only solution: > > > > -------------------------- > > let ba_char = Hashtbl.hash Bigarray.char;; > > let ba_int8_signed = Hashtbl.hash int8_signed;; > > let ba_int8_unsigned = Hashtbl.hash int8_unsigned;; > > let ba_int16_signed = Hashtbl.hash int16_signed;; > > let ba_int16_unsigned = Hashtbl.hash int16_unsigned;; > > let ba_int32 = Hashtbl.hash Bigarray.int32;; > > let ba_float32 = Hashtbl.hash float32;; > > let ba_int64 = Hashtbl.hash Bigarray.int64;; > > let ba_float64 = Hashtbl.hash float64;; > > let ba_complex32 = Hashtbl.hash complex32;; > > let ba_complex64 = Hashtbl.hash complex64;; > > let ba_int = Hashtbl.hash Bigarray.int;; > > let ba_nativeint = Hashtbl.hash Bigarray.nativeint;; > > > > let bigarray_bytes ba = > > let elt_bytes = match Hashtbl.hash (Array1.kind ba) with > > > > | x when x=ba_char || x=ba_int8_signed || x=ba_int8_unsigned -> 1 > > | x when x=ba_int16_signed || x=ba_int16_unsigned -> 2 > > | x when x=ba_int32 || x=ba_float32 -> 4 > > | x when x=ba_int64 || x=ba_float64 || x=ba_complex32 -> 8 > > | x when x=ba_complex64 -> 16 > > | x when x=ba_int || x=ba_nativeint -> > > > > Nativeint.size lsr 8 > > > > | _ -> failwith "Unknown Bigarray kind." > > > > in (Array1.dim ba) * elt_bytes;; > > -------------------------- > > > > Which is a rather ugly hack! It feels dirty like Obj.magic, while being > > completely inelegant, and even has a fail case! Can't get much worse. :) > > Of course, internally, bigarray will know it's own size... sometimes the > > price of abstraction... *sigh* > > > > I found a related Mantis entry from 6 years back: > > http://caml.inria.fr/mantis/view.php?id=3962 > > > > Well... does anyone have some better suggestions? Please? :) > > Oh, I can make it look a little prettier by plugging in the constants > eked > > out by Hashtbl.hash. ;D > > > > Why do I want this? Interfacing with OpenGL (glcaml). > > > > Thanks for looking, and more again if you have a good tip! > > Hi Anthony, > > Had the same problem with glMLite. > I use the function below, but if there is a better solution I would be > interested too: > > val ba_sizeof: ba:('a, 'b, Bigarray.c_layout) Bigarray.Array1.t -> int > > external elem_size: ba:('a, 'b, Bigarray.c_layout) Bigarray.Array1.t -> int > = "ml_ba_elem_size" "noalloc" > > let ba_sizeof ~ba = > ((Bigarray.Array1.dim ba) * (elem_size ba)) ;; > > CAMLprim value ml_ba_elem_size( value _ba ) > { > struct caml_bigarray *ba = Bigarray_val(_ba); > int size; > switch (ba->flags & BIGARRAY_KIND_MASK) > { > case BIGARRAY_SINT8: > case BIGARRAY_UINT8: > size = 1; break; > > case BIGARRAY_SINT16: > case BIGARRAY_UINT16: > size = 2; break; > > case BIGARRAY_INT32: > case BIGARRAY_FLOAT32: > case BIGARRAY_COMPLEX32: > size = 4; break; > > case BIGARRAY_INT64: > case BIGARRAY_FLOAT64: > case BIGARRAY_COMPLEX64: > size = 8; break; > > case BIGARRAY_CAML_INT: > case BIGARRAY_NATIVE_INT: > size = sizeof(value); break; > } > return Val_int(size); > } > -- Caml-list mailing list. Subscription management and archives: https://sympa-roc.inria.fr/wws/info/caml-list Beginner's list: http://groups.yahoo.com/group/ocaml_beginners Bug reports: http://caml.inria.fr/bin/caml-bugs
