Question

Like the title says, I’m looking for a function in Clojure that returns me the index of the first element in a map to satisfy a condition, I know how to do it, but if something is already available in the API I would like to us it.

Example:

(strange-fn #(even? %) '(1 3 5 7 9 4)) 
=> 5

Answer 1

You provided a list rather than a map in your example, so I assume you mean any sequence.

One simple way to do it is to just count the number of items returned from take-while:

(defn strange-fn [f coll]
  (count (take-while (complement f) coll)))

(strange-fn #(even? %) '(1 3 5 7 9 4))
;=> 5