all() and any() routines
- Posted by Ad Rienks <Ad_Rienks at COMPUSERVE.COM> Mar 20, 1997
- 1318 views
Jef Zeitlin provided us with some very nice routines, all() and any(). global function all(object o) if atom(o) then return o -- that is the letter, not 0(ZERO) end if for i = 1 to length(o) do if not o[i] then return 0 -- this *is* a ZERO end if end for return 1 end function -- all() -------------------------------------------------------- global function any(object o) if atom(o) then return o end if for i = 1 to length(o) do if i[o] then return 1 end if end for return 0 end function -- any -------------------------------------------------------- I've been checking these out, but it seems to me you can speed them up (at least in a lot of cases), by replacing the loops 'for..do /if..then... end if /end for' with a simple 'if find(0, o) then...' and 'if find(1, o) then...'. The sequence o, that is used inside the routines, is of the same length as the sequence that is passed to the routines, but it only contains 0's(FALSE) and 1's(TRUE). It seems to me that reading the sequence using 'find' is more elegant and probably quicker than using a loop inside a loop. I tested my suggested improvement to find the square of 99999 in a 100000-element sequence of squares. (Pretty useless again). In this case it took my Pentium 75 with 8Mb 0.16 seconds, whereas Jef's code took twice as much. But when I began testing it with 200000 and 300000 elements, the speed difference decreased, I think maybe because most of the time was spend writing to and reading from the hard disk. Can someone with more RAM test this? Sincerely yours, Ad. PS. I wander how long this message will take to get to the Listserver. Last time it took 2 whole days. I'm posting this one now on March 20. In the USA (Westcoast) it should be just 3 a.m.