[REBOL] Re: Extracting a series of duplicates
From: gabriele::colellachiara::com at: 5-Jul-2005 12:07
Hi David,
On Tuesday, July 5, 2005, 4:46:23 AM, you wrote:
D> I can't seem to find the right combination of functions to
D> do this: Create a series containing the values that are
D> repeated in another series. For example, if the first series is
D> [1 2 2 3 4 5 5 5 6], the new series should be [2 5]. Any hints
D> or solutions are appreciated.
Is the series sorted? If so, what about:
dups: []
lastval: none
foreach element series [
if element = lastval [append dups element]
lastval: element
]
dups: unique dups
(Note, actually this only needs that the duplicates are grouped,
not that the series is sorted.)
Regards,
Gabriele.
--
Gabriele Santilli <[gabriele--rebol--com]> --- http://www.rebol.com/
Colella Chiara software division --- http://www.colellachiara.com/
