Of course, O(log n), not O(1) - maybe next Christmas :). subseq works like a charm and does everything I need, I prefer the usability of it much over the 5 (or so in total) distinct methods in java that basically do the same, albeit a bit clunkier.
Haven't verified the performance characteristics, but as the doc says "sc must be a sorted collection", I assume it will do at least a binary search, if it doesn't use the map directly. Thanks all for the replies, the versatility of all these small clojure functions surprises me every day. On Jan 31, 9:43 am, Chouser <chou...@gmail.com> wrote: > On Sat, Jan 30, 2010 at 7:31 PM, Rowdy Rednose <rowdy.redn...@gmx.net> wrote: > > I want to have it in O(1). That's why I use a tree map in the first > > place. > > > On Jan 31, 9:15 am, Sean Devlin <francoisdev...@gmail.com> wrote: > >> If you can live with an O(n) operation, take/drop-with will do the > >> job. > > >> Sean > > >> On Jan 30, 6:59 pm, Rowdy Rednose <rowdy.redn...@gmx.net> wrote: > > >> > How would I do something like these 3 TreeMap operations with > >> > clojure's sorted-map? > > >> > The goal is to narrow down a map to include only keys with a given > >> > prefix. > > Items in a sorted map cannot be found, added, or removed in O(1). > Those operations are O(log2 n) on sorted maps and sets. > > (first m) will return the lowest-sorted item in a sorted map, > O(log2 n). > > (dissoc (key (first m))) will return a map with that first item > removed, O(log2 n), > > The subseq function can be used for efficiently walking various > sorted slices of a sorted map. > > Hope that helps, > --Chouserhttp://joyofclojure.com/ -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en
