enumerate

Enumerate

An enumeration defines a common type for a group of related values and enables you to work with those values in a type-safe way withing your code.

Enumerate is JS Pseudo-Enums inspired by Swift.

While we aren't very concerned with type-safety in JS it is sometimes still useful to have a small convention around defining a common type for a group of related values.

Enumerate provides this convention.

Version

v0.0.1

Dependencies

• Underscore or Lodash ~latest

Available Files

• Development Version of enumerate.js
• Production Version of enumerate.js
• Bundled Production Version of enumerate.js

The bundled version comes with Underscore 1.8.3 bundled in.

Installation

Html

<script src="static/js/vendor/enumerate/enumerate.min.js" ></script>
<script src="static/js/main.js"></script>

// main.js
(function(window, Enumerate){

    // ...

})(window, Enumerate);

RequireJS

// standard define
define(["app/vendor/enumerate/enumerate"], function(Enumerate){

    // ...

});

// or
// commonJS style imports
var Enumerate = require("app/vendor/enumerate/enumerate");

Node

var Enumerate = require("enumerate");

Usage

Check out the specs for more usage examples!

Check out src/enumerate.js for docs / comments!

There are essentially two ways to construct an Enumerate.Enum type:

• As an associative enum
• As an enum with a raw value

Associative Value Enum Example

Sometimes it's useful to store associated values alongside enum values. This enables the storage of additional custom information and permits this information to vary each time.

var ProductCode = new Enumerate.Enum([
    "Barcode",
    "QrCode",
    "ISBN"
]);

var Product = function(productCode) {
    this.productCode = productCode;
}

var toy = new Product( ProductCode.Barcode("85909-51226") );

console.log(toy.productCode.value()); // => 85909-51226

Raw Value Enums

Sometimes you just need a simple data structure to store some basic values for a small set of read-only object keys. This is where raw value enums come in handy.

Raw value enums can store any valid JS type.

Raw value enums should share the same data type by convention.

var direction = new Enumerate.Enum({
    North: "north",
    South: "south",
    East: "east",
    West: "west"
});

var dir = direction.North;

switch(dir) {
    case direction.North:
        console.log("To Canada!");
        break;

    case direction.South:
        console.log("To Mexico!");
        break;

    case direction.East:
        console.log("To Europe!");
        break;

    case direction.West:
        console.log("To Japan!");

    default:
        console.log("Going Nowhere!");
}

// => To Canada!

Feeling Iterable?

// iterate over enum as a list of EnumValues

_.each(direction.values(), function(enumValue){
    alert(enumValue.value());
});

// iterate over enum as a list of keys

_.each(direction.keys(), function(key){
    alert(key);
});

// iterate over enum as a list of {key, EnumValue} pairs

_.each(direction.keyValues(), function(kv){
    alert(kv.key + ": " + kv.enumValue.value())
});

Custom Types

Enumerate.EnumValue and Enumerate.Enum are extendable via a familiar .extend method.

var DirectionEnumValue = Enumerate.EnumValue.extend({
    toString: function() {
        var orig = Enumerate.EnumValue.prototype.toString.call(this);
        return "[DirectionEnumValue] " + orig;
    }
});

var DirectionEnum = Enumerate.Enum.extend({
    ValueType: DirectionEnumValue,

    toString: function() {
        var all = _(this.values()).map(function(enumValue){
            return enumValue.toString();
        });

        return all.join(" | ");
    }
});

var direction = new DirectionEnum({
    north: "north",
    south: "south",
    east: "east",
    west: "west"
});

console.log(direction.toString());
// => [DirectionEnumValue] north | [DirectionEnumValue] south | [DirectionEnumValue] east | [DirectionEnumValue] west