Use of `->` (the "thread-first" macro) Clojure

Question

http://clojuredocs.org/clojure_core/clojure.core/-%3E

(def step #(-> [(% 1) (+ (% 0) (% 1))]))
(def fib #(map first (iterate step [0 1])))

The code above generates Fib sequence, and I want to rewrite the 2nd line like below:

(def fib #(-> (iterate step [0 1]) (map first)))

or

(def fib #(-> [0 1] (iterate step) (map first)))

However, the both code failes when

(println
 (take 10 (fib))
)

with an error

java.lang.IllegalArgumentException: Don't know how to create ISeq from: clojure.core$first

Is it impossible to rewrite like these or any proper way?

Thanks.

Answer 1

You want the ->> thread-last macro.