Pub/Sub golf edition

README.md

Pub/Sub golf edition

This algorithm does heavy use of arrow functions. Use Babel if you need wider support.

Example

var pubsub = require('pub-sub');

pubsub.sub('channel', function (message) {
    if (message === 'close') { // Unsubscribe when 'close' is received'
        console.log('Shuting down...');
        return false;
    } else {
        console.log(message);
        return true;
    }
});

var countdown = 10;
var interval = setInterval(function () {
    if (--countdown) {
        pubsub.pub('channel', 'Seconds until shutdown: ' + countdown);
    } else {
        pubsub.pub('channel', 'close');
        clearInterval(interval);
    }
}, 1000);

Heavily inspired by this

annotated.js

(
  l    // List of subscriptions
  => ( // Returns a pub/sub object
    {
      pub: ( // Publish message 
        c,   // Channel
        m    // Message
      ) =>   // Returns the subscriptions list
        l = l.filter(
          i =>         // Filter subscriptions list
          i[0] != c || // Ignore other channels
          i[1](m)      // Call subscriber with the message
             !== !1    // Unsubscribe if it returns false
        )
      ,
      sub: ( // Subscribe to channel
        c,   // Channel
        f    // Subscriber
      ) =>   // Returns the lenght of the subscriptions list
        l.push([c,f])  // Add subscriber to the subscriptions list
    }
  )
)(
  [] // Initialize with an empty 
)

LICENSE.md

DON'T BLAME ME LICENSE

v0 Jun 2018

You are allowed to use, modify or distribute this piece of code as pleased. The author cannot be made responsible for anything that could derive from the use or misuse of this software.

package.json

{
  "name": "pub-sub",
  "description": "Golfed down Pub/Sub pattern in 86 bytes",
  "version": "0.0.0",
  "engines": { "node": ">=4.0.0" },
  "main": "pubsub.clean.js
}

pubsub.clean.js

exports=
// Same as pubsub.js but functions return nothing
(l=>({pub:(c,m)=>{l=l.filter(i=>i[0]!=c||i[1](m))},sub:(c,f)=>{l.push([c,f])}}))([]) // 85 bytes

pubsub.js

exports=
(l=>({pub:(c,m)=>l=l.filter(i=>i[0]!=c||i[1](m)),sub:(c,f)=>l.push([c,f])}))([]) // 81 bytes

pubsub.no.channels.array.js

exports=
/**
 * Version without channels and the pubsub object is an actual array with the listeners.
 * @example
 * var channel = (l=>Object.assign(l=[],{pub:m=>l=l.filter(f=>f(m)),sub:f=>l.push(f)}))([])
 *
 * channel.sub(function (message) {
 *   if (message === 'close') {
 *     console.log('Shutting down...');
 *     return false;
 *   } else {
 *     console.log(message);
 *     return true;
 *   }
 * });
 *
 * console.log(channel.length); // 1
 *
 * channel.forEach(function (f, i) {
 *   channel[i] = function (message) {
 *     console.log('Running function number ' + i);
 *     return f(message);
 *   };
 * });
 *
 * var countdown = 10;
 * var interval = setInterval(function () {
 *     if (--countdown) {
 *         channel.pub('Seconds until shutdown: ' + countdown);
 *     } else {
 *         channel.pub('close');
 *         clearInterval(interval);
 *     }
 * }, 1000);
 **/
(l=>Object.assign(l=[],{pub:m=>l=l.filter(f=>f(m)),sub:f=>l.push(f)}))([]) // 75 bytes

pubsub.no.channels.js

exports=
/**
 * Version without channels.
 * @example
 * var channel = (l=>({pub:m=>l=l.filter(f=>f(m)),sub:f=>l.push(f)}))([])
 *
 * channel.sub(function (message) {
 *   if (message === 'close') {
 *     console.log('Shutting down...');
 *     return false;
 *   } else {
 *     console.log(message);
 *     return true;
 *   }
 * });
 *
 * var countdown = 10;
 * var interval = setInterval(function () {
 *     if (--countdown) {
 *         channel.pub('Seconds until shutdown: ' + countdown);
 *     } else {
 *         channel.pub('close');
 *         clearInterval(interval);
 *     }
 * }, 1000);
 **/
(l=>({pub:m=>l=l.filter(f=>f(m)),sub:f=>l.push(f)}))([]) // 57 bytes