compose() & pipe()

Snippet

I go over function composition in this blog post, so please read the post for a more detailed explanation.

const compose =
  (...fns) =>
  x =>
    fns.reduceRight((acc, fn) => fn(acc), x)

const pipe =
  (...fns) =>
  x =>
    fns.reduce((acc, fn) => fn(acc), x)

If you want to get real fancy, you can split out and share the reducer.

const apply = (value, fn) => fn(value)

const compose =
  (...fns) =>
  x =>
    fns.reduceRight(apply, x)

const pipe =
  (...fns) =>
  x =>
    fns.reduce(apply, x)

Liked the post?

Give the author a dopamine boost with a few "beard strokes". Click the beard up to 50 times to show your appreciation.

Kyle Shevlin is the founder & lead software engineer of Agathist, a software development firm with a mission to build good software with good people.