Update exploring.clj

[ssisksl77]

line56 (defn index-filter [pred coll](when pred %28for [[idx elt] %28indexed coll%29 :when %28pred elt%29] idx%29))

I think that 'when' is not necessary. and I've changed like this.

(defn index-filter [pred coll](for [[idx elt] %28indexed coll%29 :when %28pred elt%29] idx))

please check this out. If I am wrong. I'd be grateful that If you send me an email. [email protected]