On Friday 10 August 2007 12:37:31 Andrew Coppin wrote:
Stefan O'Rear wrote:
Bool is 32 bits, but Don is using UArray. UArray is not parametric in the element type, which means it's less generally useful (no UArray of Complex Double, for instance), but conversely it is able to use more efficient representations depending on the type.
Would be nice if it *could* somehow be parametric... but I have absolutely no idea how you'd do that. The transformation is self-evident enough to a human, but how do you explain it to a machine?
Check out the various papers, slides, and talks on NDP/parrallel arrays. There's much discussion on schemes to efficiently pack data types into unboxed arrays. Cheers, Spencer Janssen
(I somewhat suspect you'd have to bake this into the compiler itself it you wanted *arbitrary* types. Otherwise you'd have to write some special class that knows how to pack and unpack the data from the array, perhaps as a bundle of Word8s or something? Doesn't sound hugely fast...)