Enums

Enums define a set of named constants.

Basic Enum

Values are auto-numbered starting from 0:

enum Color
    Red
    Green
    Blue
end

Compiles to:

local Color = {Red = 0, Green = 1, Blue = 2}

Explicit Values

enum HttpStatus
    Ok = 200
    NotFound = 404
    ServerError = 500
end

String Enums

enum Direction
    Up = "up"
    Down = "down"
    Left = "left"
    Right = "right"
end

String enums compile to a bidirectional lookup table:

local Direction = {Up = "up", Down = "down", Left = "left", Right = "right"}
Direction["up"] = "Up"
Direction["down"] = "Down"
-- ...

Usage

local c = Color.Red
if c == Color.Green then
    print("Green!")
end

Enums in Match

match status
case HttpStatus.Ok then
    print("Success")
case HttpStatus.NotFound then
    print("Not found")
case _ then
    print("Other")
end

Iteration

Enums are iterable:

for name, value in pairs(Color) do
    print(name, value)
end

Exported Enums

export enum Severity
    Low
    Medium
    High
    Critical
end