From cd5eb04c4f020cdd5cf1908656a93969ef4ac056 Mon Sep 17 00:00:00 2001 From: Justin Lee Date: Thu, 14 Dec 2017 14:44:38 -0800 Subject: [PATCH] Rewrote pipe such that the first function may have any arity. --- snippets/pipe.md | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/snippets/pipe.md b/snippets/pipe.md index c61ec042c..11803210c 100644 --- a/snippets/pipe.md +++ b/snippets/pipe.md @@ -1,8 +1,18 @@ ### Pipe -Use `Array.reduce()` to pass value through functions. +Use `Array.reduce()` to perform left-to-right function composition. The first (leftmost) function can accept one or more arguments; the remaining functions must be unary. ```js -const pipe = (...funcs) => arg => funcs.reduce((acc, func) => func(acc), arg); -// pipe(btoa, x => x.toUpperCase())("Test") -> "VGVZDA==" +const pipe = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args))) +/* +const add5 = (x) => x + 5 +const multiply = (x, y) => x * y + +const multiplyAndAdd5 = pipe( + multiply, + add5 +) + +multiplyAndAdd5(5, 2) -> 15 +*/ ```