Enums

Enums declare a fixed set of named variants. They are compile-time constants, not objects.

Declaring an enum

enum TokenKind:
    IDENT
    NUMBER
    EOF

Variants are implicitly ordered starting from 0. There are no explicit numeric assignments.

Using enum values

enum TokenKind:
    IDENT
    NUMBER
    EOF

class Token:
    kind: TokenKind
    text: str

def is_ident(kind: TokenKind) -> bool:
    return kind == TokenKind.IDENT

def main() -> None:
    kind = TokenKind.NUMBER
    kinds: list[TokenKind] = [TokenKind.IDENT, TokenKind.EOF]
    token = Token(TokenKind.IDENT, "x")
    names: dict[TokenKind, str] = {
        TokenKind.IDENT: "id",
        TokenKind.NUMBER: "num"
    }
    print(kind)
    print(kinds)
    print(token)
    print(names)
    print(is_ident(token.kind))

Printing

Enum values print by variant name:

def main() -> None:
    print(TokenKind.IDENT)   # IDENT

Module-qualified access

When importing from another module:

from shapes import Color

def main() -> None:
    c = Color.RED
    print(c)

import shapes

def main() -> None:
    c = shapes.Color.RED
    print(c)

Limits

• Enum definitions are module-scope only.
• No methods on enums.
• No explicit numeric values.
• Up to 64 variants per enum.
• Enums cannot participate in general unions (only Enum | None is supported).