to get O(1) lookup, you can use sparse arrays. if you don't have numeric keys, you need a function that will map 1to1 text keys to a number (simplest such function concatenates ascii values).
--- June Kim <[EMAIL PROTECTED]> wrote: > Hello. > > I have asked if there is hash facility in J for a > couple of times. At > first, I thought J's dict class(j-n/z/w-dict) was > one. However, it > isn't. (actually, dictionary = map = hash across > many modern > programming languages) > > Since the key/value table is dynamically updated, > m&i. code > specialization doesn't work(the dict implementation > doesn't use that > code either) and hence the lookup time is O(N), > instead of O(1), which > is expected for real hash implementations. > > In this reason, dict class is inhibitively expensive > for using like a > dictionary in spite of the name and its name may > confuse J novices. > > Does any one have real hash implementations in J? If > not, I might have > to start to make one. > > June > ---------------------------------------------------------------------- > For information about J forums see > http://www.jsoftware.com/forums.htm > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
