ExUnion is meant to be a lightweight, elixir-y implementation of tagged unions (also called variant, discriminated union, sum type, etc.).

While conventionally Elixir tends to promote using tuples to model tagged unions - the {:ok, …} | {:error, …} pattern being a good example of that - this approach arguably lacks expressiveness, especially when modeling non-trivial unions. An alternative is to employ structs to model the individual cases of a tagged union, which works nicely but has the disadvantage of requiring significant boilerplate code.

ExUnion attempts to bridge this gap by generating the necessary boilerplate (and a bit more) through a concise albeit opinionated DSL.

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• Hex.pm
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