On 7/13/06, R&S HUI <[EMAIL PROTECTED]> wrote:
For swapping items, x A. y has a high "gee whiz" factor, but (<i,j)C. y is more practical. For example, to swap last two items, one could say 1&A. or (<_1 _2)&C. . To swap the first two items, (<0 1)&C. does it. To do it using A. is less straightforward.
Yes. But assuming in place operations are easier at the distal end...? The A. is quite perspicuous - more terse, much like o. For stack operations, one end is good enough. If you could do in place swap operations more generically say those which preserved element sizes and array shape ... well the whole world of group theory is your oyster. i could use a lot of efficient in place operations, eg moving sprites around in a bitmap... ~greg ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
