Clojure: adding indexes to map vectors

I have a vector map I want to associate an index element with each element

Example:

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

Should come back

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

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

Solution

First, clojure starts calculating the vector elements in 0, so you may want to get

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

You can easily do this with the map indexed function

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