babel-plugin-pipe-composition

Overload the bitwise operators (<<) and (>>) to provide F# like pipe forward/backward behavior.

This is an alternative to babel-plugin-pipe-operator and babel-plugin-pipe-operator-curry and favours the currying approach instead of using the first callable argument.

Examples

import { mean, round } from 'lodash';

const array = [1, 2, 3, 4, 5];

// regular javascript
round(mean(array));

// typical composition helpers
pipe(mean, round)(array);
compose(round, mean)(array);

// composition with pipe operators
array
 >> mean
 >> round

round
  << mean
  << array

import { map, filter } from 'ramda';

const array = [1, 2, 3, 4, 5];

// regular javascript
filter(n => n % 3 == 0)(map(n => n * 2)(array))

// typical composition with javascript
pipe(map(n => n * 2), filter(n => n % 3 == 0))(array);
compose(filter(n => n % 3 == 0), map(n => n * 2))(array);

// composition with pipe operators
let result = array
  >> map(n => n * 2)
  >> filter(n => n % 3 == 0);

let result = filter(n => n % 3 == 0)
  << map(n => n * 2)
  << array;

Disabling in current scope

If you want to use the original bitwise operators, you can disable this plugin in current scope (and child scopes) using the "no pipe" directive.

const fn = () => {
  const arr = [1, 2, 3] >> map(n => n + 1);

  return () => {
    "no pipe";

    arr.map(n => n >> 1);
  };
};

const fn = () => {
  const arr =  map(n => n + 1) << [1, 2, 3];

  return () => {
    "no pipe";

    arr.map(n => 1 << n);
  };
};

Installation

$ npm install --save-dev babel-plugin-pipe-composition

Usage

Via .babelrc (Recommended)

{
  "plugins": ["pipe-composition"]
}

Via CLI

$ babel --plugins pipe-composition script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["pipe-composition"]
});

License

MIT