callbag-pipe

/**

• callbag-pipe

• ---

• Utility function for plugging callbags together in chain. This utility
• actually doesn't rely on Callbag specifics, and is really similar to
• Ramda's pipe or lodash's flow.
• Implementation of callbag-pipe using R.pipe could look like this:
• const pipe = (source, ...cbs) => R.pipe(...cbs)(source)
• This exists to play nicely with the ecosystem,
• and to facilitate the import of the function.
• npm install callbag-pipe
• Example:
• Create a source with pipe, then pass it to a forEach:

• const interval = require('callbag-interval');
  

• const forEach = require('callbag-for-each');
  

• const combine = require('callbag-combine');
  

• const pipe = require('callbag-pipe');
  

• const take = require('callbag-take');
  

• const map = require('callbag-map');
  

• const source = pipe(
  

•   combine(interval(100), interval(350)),
  

•   map(([x, y]) => `X${x},Y${y}`),
  

•   take(10)
  

• );
  

• forEach(x => console.log(x))(source); // X2,Y0
  

•                                       // X3,Y0
  

•                                       // X4,Y0
  

•                                       // X5,Y0
  

•                                       // X6,Y0
  

•                                       // X6,Y1
  

•                                       // X7,Y1
  

•                                       // X8,Y1
  

•                                       // X9,Y1
  

•                                       // X9,Y2
  

• Or use pipe to go all the way from source to sink:

• const interval = require('callbag-interval');
  

• const forEach = require('callbag-for-each');
  

• const combine = require('callbag-combine');
  

• const pipe = require('callbag-pipe');
  

• const take = require('callbag-take');
  

• const map = require('callbag-map');
  

• pipe(
  

•   combine(interval(100), interval(350)),
  

•   map(([x, y]) => `X${x},Y${y}`),
  

•   take(10),
  

•   forEach(x => console.log(x))
  

• );
  

• // X2,Y0
  

• // X3,Y0
  

• // X4,Y0
  

• // X5,Y0
  

• // X6,Y0
  

• // X6,Y1
  

• // X7,Y1
  

• // X8,Y1
  

• // X9,Y1
  

• // X9,Y2
  

• Nesting

• ---

• To use pipe inside another pipe, you need to give the inner pipe an
• argument, e.g. s => pipe(s, ...:

• const interval = require('callbag-interval');
  

• const forEach = require('callbag-for-each');
  

• const combine = require('callbag-combine');
  

• const pipe = require('callbag-pipe');
  

• const take = require('callbag-take');
  

• const map = require('callbag-map');
  

• pipe(
  

•   combine(interval(100), interval(350)),
  

•   s => pipe(s,
  

•     map(([x, y]) => `X${x},Y${y}`),
  

•     take(10)
  

•   ),
  

•   forEach(x => console.log(x))
  

• );
  

• This means you can use pipe to create a new operator:

• const mapThenTake = (f, amount) =>
  

•   s => pipe(s, map(f), take(amount));
  

• pipe(
  

•   combine(interval(100), interval(350)),
  

•   mapThenTake(([x, y]) => `X${x},Y${y}`, 10),
  

•   forEach(x => console.log(x))
  

• );
  

*/

function pipe(...cbs) { let res = cbs[0]; for (let i = 1, n = cbs.length; i < n; i++) res = cbsi; return res; }

module.exports = pipe;