J has bit arrays, though it's true that they could be a factor of 8 more space efficient by removing padding and making the J implementation somewhat bulkier.
But you can pad your arrays yourself if you want to test whether row alignment introduces timing advantages for frequent operations. It would be interesting to see what you come up with there. Thanks, -- Raul On Mon, Aug 2, 2021 at 4:01 PM Elijah Stone <[email protected]> wrote: > > Apologies if this is the wrong place for this. > > First: what's the deal with bitarrays? I have heard APL implementors > state with great conviction that they are worthwhile and have led to great > performance increases; and I have heard J implementors state with equal > conviction that they are not worth their while at all. I don't know whom > to believe! > > Second: is it worth it to add padding for >1-rank arrays? It seems > convenient for major cells (and perhaps more minor cells as well) to be > aligned, and I know of at least one high-performance in-place high-rank > transposition algorithm which requires some degree of padding/alignment. > J's array structure doesn't seem to make any allowance for more than one > shape. Has this approach been tried and found lacking, or is it just > untrodden ground? > > -E > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
