Err, this was bugging me all day when I went afk. I wrote it too quickly and am missing the case where the sub-seq starts right after seeing the first val, [:b :b :c].
Will fix it if I have time today, but may need to take a slightly different approach. Fun problem, btw. :) On Saturday, June 7, 2014 2:31:04 PM UTC-5, Alex Walker wrote: > > Here's a solution based on your description that behaves like core > partition fns, taking liberty to presume your example should've matched the > output below. > > (defn partition-by-seq > [sub-seq coll] > (letfn [(step [coll] > (when-let [coll (seq coll)] > (let [[run more] (split-with (partial not= (first sub-seq)) > coll) > [possible-match more] (split-at (count sub-seq) more)] > (if (= possible-match sub-seq) > (if (seq run) > (cons run (cons possible-match (lazy-seq (step > more)))) > (cons possible-match (lazy-seq (step > more)))) > (cons (concat run possible-match) (lazy-seq (step > more)))))))] > (or (step coll) ()))) > > => (partition-by-seq [:b :c] []) > > () > > => (partition-by-seq [:b :c] [:a :d]) > > ((:a :d)) > > => (partition-by-seq [:b :c] [:a :b :c :d :a :b :c :d :a :b :c]) > > ((:a) (:b :c) (:d :a) (:b :c) (:d :a) (:b :c)) > > > > On Tuesday, June 3, 2014 4:05:16 AM UTC-5, Ulrich Küttler wrote: >> >> Hi, >> >> what is the preferred way to find sub-seqs in a seq? I am trying to >> convert >> >> [:a :b :c :d :a :b :c :d :a :b :c] >> >> into >> >> ((:a) (:b :c) (:a :d) (:b :c) (:a)) >> >> using the sub-seq (:b :c) instead of positions. >> >> partition, partition-by and the like all look at one element at a time. >> What I need is a search based on seqs. Are there functions that support >> such a search / split? >> >> Uli >> > -- 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/d/optout.
