Pipe functions left to right

Arguments

...fnsFunction[]

Any number of unary functions. The leftmost one may take any number of arguments.

Returns

Function — A function that applies fns left to right, threading the output of each into the next.

Examples

const trim = (s) => s.trim();
const split = (s) => s.split(" ");
const count = (parts) => parts.length;

const wordCount = pipe(trim, split, count);
wordCount("  hello world  "); // 2

pipe((a, b) => a + b, (n) => n * 10)(2, 3); // 50

What it has to do

• Apply the functions left to right.
• Pass every argument to the leftmost function; the rest each receive one value.
• With no functions, return the first argument unchanged.
• Support a chain of more than two functions whose types change along the way.

Notes

• pipe(f, g)(x) === g(f(x)). Same machinery as compose, opposite direction — pick whichever reads better at the call site.
• This is the shape of RxJS's pipe and of the stage-2 pipeline operator proposal (x |> f |> g). Learn it once, apply it everywhere.