The second one is actually a PersistentArrayMap and hence properties that might indicate (falsely) that it's a sorted-map (aka PersistentTreeMap). Clojure uses PersistentArrayMap for small maps as an optimisation and automatically promotes to PersistentHashMap when the number of items crosses a certain threshold (32, IIRC).
Regards, BG On Mon, Sep 30, 2013 at 3:54 PM, Gavin Sinclair <gsincl...@gmail.com> wrote: > I have a value 'y' in my REPL that is a sequence containing two sequences of > numbers: > > (def y '( > (15 18 17 17 16 19 16 10 21 16 21 23 19 16 18 15 21 14 21 > 12 26 17 13 22 26 16 14 17 11 15 16 18 13 10 18 18 19 13 > 14 17 19 18 15 20 20 17 20 19 12 20 14 21 13 17 15 22 17 > 21 13 15 16 17 14 21 14 15 17 16 25 22 13 19 23 20 16 16 > 17 13 15 19 20 14 15 17 13 17 11 17 16 20 16 20 15 14 13 > 18 18 17 15 16 15 18 28 12 20 16 17 22 20 23 15 16 21 24 > 18 18 18 18 14 18 21 15 12 19 19 16 12 15 21 19 18 17 16 > 17 16 18 18 12 18 18 17 20 21 15 20 19 19 15 21 17 13 18 > 11 19 18 21 17 23 15 16 17 17 15 17 17 15 15 14 19 18 18 > 14 17 14 18 25 24 11 20 15 13 20 18 16 20 20 16 16 18 15 > 18 22 18) > > (24 18 20 17 19 19 20) > )) > When I ask for the frequencies of the two sequences, one is a sorted map and > the other is unsorted. > > => (keys (frequencies (first y))) > (10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 28) > => (keys (frequencies (second y))) > (24 18 20 17 19) > > The classes of the maps don't indicate that the first map is indeed sorted, > but it cannot be a coincidence that they keys are returned in order. (I > tried it with some more data concatenated and it was still in order.) > > The source for 'frequencies' (version 1.5.1) does not reveal to me why I get > sorted in one case and unsorted in the other. It must be to do with the > length of the sequence, but what is the full explanation? > > Thanks, > Gavin > > -- > -- > 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 > --- > You received this message because you are subscribed to the Google Groups > "Clojure" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to clojure+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/groups/opt_out. -- Baishampayan Ghose b.ghose at gmail.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 --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
