Clojure中的向量列表中的元素编号

Question

I have a list of vectors I want to number. For instance, I have the following list of vectors

(["blah1" "blah2" "blah3"]
 ["clah1" "clah2" "clah3"]
 ["flah1" "flah2" "flah3"])

and would like something this:

(["line 1" "blah1" "blah2" "blah3"]
 ["line 2" "clah1" "clah2" "clah3"]
 ["line 3" "flah1" "flah2" "flah3"]) 

Answer 1

map takes several sequences as last argument:

user=> (map vector (iterate inc 1) '(a b c d))
([1 a] [2 b] [3 c] [4 d])

Answer 2

map-indexed can do the trick.

(map-indexed (fn [i v]
               (into [(str "line " (inc i))] v))
             [["blah1" "blah2" "blah3"]
              ["clah1" "clah2" "clah3"]
              ["flah1" "flah2" "flah3"]])
;; => (["line 1" "blah1" "blah2" "blah3"] ["line 2" "clah1" "clah2" "clah3"] ["line 3" "flah1" "flah2" "flah3"])