ExEnum

ExEnum is a simple enumeration library for Elixir.

Usage

Just add the following line to your Elixir module and you are ready to go.

use ExEnum, from: [ ... ]

By adding the above line to your module, it will automatically acquire the following functionality:

Ability to list all the values in the enumeration
Ability to check if an arbitrary value belongs to the enumeration
Ability to access a value from the enumeration via a dedicated accessor function
Ability to list all the keys that can be used to access each of the enumeration values

This functionality is realised by means of the following functions: values/0, is_valid?/1, from_value/1, keys/0 and \<key>/0. Note that your module will have as many \<key>/0 functions as enumeration values in the use ExEnum, from: [ ... ] clause.

Example(s)

defmodule Planet do
    use ExEnum, from: [
        "MERCURY",
        "VENUS",
        "EARTH",
        "MARS",
        "JUPITER",
        "SATURN",
        "URANUS",
        "NEPTUNE"
    ]
end

Planet._MERCURY
# => "MERCURY"

Planet.values
# => ["MERCURY", "VENUS", "EARTH", "MARS", "JUPITER",
#     "SATURN", "URANUS", "NEPTUNE"]

Planet.keys
# => [:_MERCURY, :_VENUS, :_EARTH, :_MARS, :_JUPITER,
#     :SATURN, :_URANUS, :_NEPTUNE]

Planet.is_valid?("PLUTO")
# => false

Planet.from_value("EARTH")
# => "EARTH"

Planet.is_valid?("PLUTO")
# => nil

defmodule Direction do
    use ExEnum, from: [
        {:north, 1},
        {:east, 2},
        {:south, 3},
        {:west, 4}
    ]
end

Direction.north
# => 1

Direction.values
# => [1, 2, 3, 4]

Direction.keys
# => [:north, :east, :south, :west]

Direction.is_valid?(:north_east)
# => false

Direction.from_value(:north_east)
# => nil

Direction.from_value(:north)
# => 1

Installation

If available in Hex, the package can be installed as:

Add ExEnum to your list of dependencies in mix.exs:
def deps do
```
 [{:exenum, "~> 0.0.1"}]
```
end
Ensure ExEnum is started before your application:
def application do
```
 [applications: [:exenum]]
```
end

Author(s)

Enrique Fernandez <efcasado(at)gmail.com>

License

The MIT License (MIT)
Copyright (c) 2016, Enrique Fernandez
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.