And this is mine (defn keycollect-too [key-fn coll] (let [not-key (complement key-fn)] (loop [[k & more] coll, res (transient {})] (let [[vv rr] (split-with not-key more)] (if-not k (persistent! res) (recur rr (assoc! res k (vec vv))))))))
(keycollect-too keyword? [:key1 1 2 3 :key2 4 :key3 5 6 7]) => {:key1 [1 2 3], :key2 [4], :key3 [5 6 7]} Thanks. On Wednesday, February 20, 2013 6:50:42 AM UTC-5, Stefan Kamphausen wrote: > > Hi, > > given a vector of the form > > > > [:key1 1 2 3 :key2 4 :key3 5 6 7] > > I wand to create a map collecting the items behind each keyword as a vector > like this: > > {:key1 [1 2 3] > :key2 [4] > :key3 [5 6 7]} > > I have already written two functions which achieve this, but neither of them > "feels good" and I am interested in more elegant and idiomatic solutions. > > (defn keycollect-partition [coll] > (->> coll > (partition-by keyword?) ; bundle at key > (partition 2) ; kw + its arg > (map (fn [[[sec] arg]] [sec (vec arg)])) ; destruct the mess > (into {}))) ; make it a map > > (defn keycollect-reduce [coll] > (apply zipmap > (reduce > (fn [ac x] > (if (keyword? x) > [(conj (first ac) x) (conj (second ac) [])] > (update-in ac [1 (dec (count (first ac)))] conj x))) [[] []] > coll))) > > Added complexity: My original vector does not yet contain keywords, but I > construct them in a map regexp-matching each item and creating a keyword from > the first group of the match. > > Any pointers or ideas appreciated. > > Regards, > Stefan > > > > -- -- 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.