clojure: add index to vector of maps

Question

I have a vector of maps. I want to associate an index element for each element.

Example:

(append-index [{:name "foo"} {:name "bar"} {:name "baz"}])

should return

[{:name "foo" :index 1} {:name "bar" :index 2} {:name "baz" :index 3}]

What is the best way to implement append-index function?

Answer 1

just adding some fun:

(defn append-index [items]
  (map assoc items (repeat :index) (range)))

Answer 2

First of all, Clojure starts counting vector elements from 0, so you probably want to get

[{:index 0, :name "foo"} {:index 1, :name "bar"} {:index 2, :name "baz"}]

You could do it pretty easily with map-indexed function

(defn append-index [coll]
  (map-indexed #(assoc %2 :index %1) coll))