Overlord-js NPM

Overloading javascript functions like a overlord

Overlord-js is a module which allows you to overload functions in a pseudo-functional style

Installation

NPM

npm install overlord-js --save

Usage

Usage on server-side

var overlord = require('overlord-js');

var say = overlord([
    {
        args: [String],
        func: function(name) {
            return "Hi, " + name;
        }
    }, {
        args: [String, Number],
        func: function(name, meters) {
            return name + " ran " + meters + " meters";
        }
    }, {
        args: [
            String, 
            Number, 
            Array
        ],
        check: [
            /^S/, 
            7, 
            function(arr) {
                if (arr.indexOf('commandos') !== -1) {
                    return true;
                } else {
                    return false;
                }
            }
        ],
        func: function(name, age, games) {
            var game, gameStr, i, j, len;
            gameStr = '';
            for (i = j = 0, len = games.length; j < len; i = ++j) {
                game = games[i];
                if (i > 0 && i < games.length - 1) {
                    gameStr += ', ';
                } else if (i === games.length - 1) {
                    gameStr += ' and ';
                }
                gameStr += game;
            }
            return "In " + age + " years, " + name + " was playing: " + gameStr;
        }
    }, {
        args: ['any', 'any'],
        func: function(var_1, var_2) {
            if (var_1 === var_2) {
                return "Equivalent";
            } else {
                return "Not equivalent";
            }
        }
    }, {
        args: [String, String, '...'],
        func: function() {
            return "We got " + arguments.length + " arguments";
        }
    }, {
        args: [],
        func: function() {
            return "No one variable";
        }
    }
], function() {
    return "Oops, custom call";
});

console.log( say('Sasha') );                                        // Hi, Sasha
console.log( say('Sasha', 10) );                                    // Sasha ran 10 meters
console.log( say('Sasha', 7, ['commandos', 'nfs', 'warcraft']) );   // In 7 years, Sasha was playing: commandos, nfs and warcraft
console.log( say('Sasha', 5, ['commandos', 'nfs', 'warcraft']) );   // Oops, custom call
console.log( say('Artem', 7, ['commandos', 'nfs', 'warcraft']) );   // Oops, custom call
console.log( say('Sasha', 7, ['hugo', 'nfs', 'warcraft']) );        // Oops, custom call
console.log( say(5, 'five') );                                      // Not equivalent
console.log( say(10, 10) );                                         // Equivalent
console.log( say('one', 'two', 'three', 'four') );                  // We got 4 arguments
console.log( say('one', 'two', 'three', 'four', 'five') );          // We got 5 arguments
console.log( say() );                                               // No one variable
console.log( say(1, [], false) );                                   // Oops, custom call

Usage on client-side

<html lang="ru-RU">
<head>
    <meta charset="UTF-8" />
    <title>Overlord.js - bow down before the Lord</title>
    <script type="text/javascript" src="./overlord-v1.1.0-min.js"></script>
</head>
<body>
    <script type="text/javascript">
    var say = overlord([
        {
            args: [String],
            check: [/^(?:S|A|L)/],
            function: function(name) {
                return "Hi, " + name;
            }
        }
    ],  function() {
        return "Oops, custom call";
    });
    
    console.log(say('Sasha'));                  // Hi, Sasha
    console.log(say('Lesha'));                  // Hi, Lesha
    console.log(say('Artem'));                  // Hi, Artem
    console.log(say('Motja'));                  // Oops, custom call
    console.log(say(1, [], false));             // Oops, custom call
    </script>
</body>

API

overlord(overloads, default, error)

array overloads - array of functions.
- object - information about single function
  - array args - array of prospective types of arguments. example: String, Numberd
    - String, Number, Object, Array, Function, RegExp, Undefined - for the type of a variable
    - 'any' - for any type
    - '...' - for zero or more any type. It is available from the arguments like arguments[3]
    - null- For zero variables
  - function function or func - The called function, if types of arguments match
  - array check - optional - array of expected value, regular expression or checking function of verifiable argument
    - String, Number, Object, Array - expected value of the argument. Validate by == operator. example: 'foo'
    - RegExp - a regular expression to validate the argument. example: /^www/
    - Function - custom checking function. function should return true or false for validate argument. example: function( arg ){ if(arg == 'foo') return true; else return false }
function default - function() If none of the options didn't approach then this function will be called. default: undefined
boolean error - If none of the option didn't approach, default function not defited and it set to true, will be emit event Cannot read property 'apply' of undefined . default: false

Test

Run the mocha test

Current test runs for 8-10 ms

npm test

Or for old

mocha test/test.v< version >.js

Build form coffee source

Build project

gulp build

Build only browser files

gulp browserify

Clear all compiled files

gulp clear

Innovations in version

1.1.0

custom arguments validation of overload

var say = overlord([
    {
    args: [String, Number, Array], 
    check: [
        /^S/,               // Using regular expressions
        7,                  // expected value
        function(arr) {     // or custom function
            if (arr.indexOf('commandos') !== -1) return true; // Valid
            else return false;
        }
    ],
    func: function(name, age, games) {
        // ...
    }
])

Changelog

1.1.2 `Stable`

Add - property of overload check. It may be a expected value, regular expression or checking function of verifiable argument. Example
Add - func alias for function property of overload.
Add - throw error when overload property func|function or args not set