thread first (->)

threads value through calls as their first argument

Evaluates expr and threads it through the supplied forms as their first argument. Any form that is not already a function call will be converted into one before threading.

An Example

(-> 0 (+ 10) (\* 2) (/ 5))

Will expand to (/ (\* (+ 0 10) 2) 5) and return 4.