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README.md

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 Enum type in Elixir known from [Java](https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html) or [C#](https://msdn.microsoft.com/en-us/library/vstudio/cc138362).
 
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 Either in Java or in C# there is `enum` type available. It is a special data type that enables for a variable to be a set of predefined constants. The variable must be equal to one of the values that have been predefined for it. Common examples include compass directions (values of `NORTH`, `SOUTH`, `EAST`, and `WEST`) and the days of the week. You should use enum types any time you need to represent a fixed set of constants. That includes natural enum types such as the planets in our solar system and data sets where you know all possible values at compile time—for example, the choices on a menu, command line flags, and so on.
 
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