pipe

Performs consecutive operations on a value in TypeScript. An alternative library of the proposal of Pipe Operator (|>) for JavaScript. It supports type inference and type checking of the operator functions.

Usage

Pipe a value through a series of operator functions.

import { pipe } from "@core/pipe/pipe";

const result = pipe(
  1,
  (v) => v + 1, // inferred as (v: number) => number
  (v) => v * 2, // inferred as (v: number) => number
  (v) => v.toString(), // inferred as (v: number) => string
);
console.log(result); // "4"

Or use async module to pipe a value through a series of asynchronous operator functions.

import { pipe } from "@core/pipe/async/pipe";

const result = await pipe(
  1,
  (v) => Promise.resolve(v + 1), // inferred as (v: number) => number | Promise<number>
  (v) => Promise.resolve(v * 2), // inferred as (v: number) => number | Promise<number>
  (v) => Promise.resolve(v.toString()), // inferred as (v: number) => string | Promise<string>
);
console.log(result); // "4"

If you want to create a new function that composes multiple operators, use compose like below.

import { compose } from "@core/pipe/compose";

const operator = compose(
  (v: number) => v + 1, // The first operator must be typed explicitly
  (v) => v * 2, // inferred as (v: number) => number
  (v) => v.toString(), // inferred as (v: number) => string
);
console.log(operator(1)); // "4"

Or use async module to compose multiple asynchronous operators.

import { compose } from "@core/pipe/async/compose";

const operator = compose(
  (v: number) => Promise.resolve(v + 1), // The first operator must be typed explicitly
  (v) => Promise.resolve(v * 2), // inferred as (v: number) => number | Promise<number>
  (v) => Promise.resolve(v.toString()), // inferred as (v: number) => string | Promise<string>
);
console.log(await operator(1)); // "4"

Difference

The pipe function in the root module is equivalent to function calls without await like below.

import { pipe } from "@core/pipe/pipe";

const a = (v: unknown) => v;
const b = (v: unknown) => v;
const c = (v: unknown) => v;

// Equivalent
console.log(pipe(1, a, b, c)); // 1
console.log(c(b(a(1)))); // 1

The pipe function in the async module is equivalent to function calls with await like below.

import { pipe } from "@core/pipe/async/pipe";

const a = (v: unknown) => Promise.resolve(v);
const b = (v: unknown) => Promise.resolve(v);
const c = (v: unknown) => Promise.resolve(v);

// Equivalent
console.log(await pipe(1, a, b, c)); // 1
console.log(await c(await b(await a(1)))); // 1

License

The code follows MIT license written in LICENSE. Contributors need to agree that any modifications sent in this repository follow the license.