Okay, both these answers make lots of sense. thank you for your help. J
On Wednesday, May 14, 2014 11:47:51 AM UTC+9, Guru Devanla wrote: > > The call to (index) returns this vector > > ([0 \:] [1 \a] [2 \space] [3 \4] [4 \space] [5 \:] [6 \b] [7 \space] [8 > \1] [9 \space] [10 \:] [11 \c] [12 \space] [13 \3] [14 \space] [15 \:] [16 > \d] [17 \space] [18 \4]) > > And, 3 here is in the 13th position. Your (cond) in index function is > picking up the :else branch. > > > On Tue, May 13, 2014 at 6:44 PM, gamma235 <jesus.d...@gmail.com<javascript:> > > wrote: > >> I am reading The Joy of Clojure now and am finishing chapter 5 on >> sequence abstractions. There is an example given that demonstrates how to >> locate the index of an element in a sequence by value, but I don't >> understand why the character lookup here is returning 13. Can somebody >> please explain this to me? >> >> (defn index [coll] >>> (cond >>> (map? coll) (seq coll) >>> (set? coll) (map vector coll coll) >>> :else (map vector (iterate inc 0) coll))) >>> >>> (defn pos [pred coll] >>> (for [[i v] (index coll) :when (pred v)] i)) >>> >> >> >>> (pos \3 ":a 4 :b 1 :c 3 :d 4") >> >> >> >> => 13 >> >> >> J >> >> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com<javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> 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+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > -- 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.
