Function composition¶

Here are a few ways to create new functions from existing functions:

comp¶

Give a collection of functions: [ fa fb fc ] and a value x, comp does this:

(->> x
    fc
    fb
    fa)

Note that the order of the functions is reversed, e.g:

(->> { :a {:in-a "a's value"} :c "c's value"}
    ((comp :in-a :a)))
;; "a's value"

Given a collection of functions: [ fa fb ] and a value x, juxt applies all the functions to x and return a collection of the results:

(->> { :a {:in-a "a's value"} :c "c's value"}
     ((juxt :a :c)))
;; [{:in-a "a's value"} "c's value"]