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Enumerated Types

When modeling state machines it can be useful to describe variants of a single type that can contain different values. This concept is simple enough to describe optional types or complex enough to model multi-state systems.

Definition​

Use the enum keyword to define enumerated types with one or more variants.

knot
enum CardSuit =
  | Spade
  | Diamond
  | Club
  | Heart;
knot
enum CardSuit =
  | Spade
  | Diamond
  | Club
  | Heart;

Constructor Arguments​

Each enum variant can optionally specify some data that it must take as arguments during construction, and can be extracted when destructuring.

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enum Primitive =
  | Nil
  | Boolean(boolean)
  | Integer(integer)
  | Float(float)
  | String(string);
knot
enum Primitive =
  | Nil
  | Boolean(boolean)
  | Integer(integer)
  | Float(float)
  | String(string);