expr.py

from token_ import Token
from abc import ABCMeta, abstractmethod


class Expr:
    pass


class IVisitor(metaclass=ABCMeta):
    @abstractmethod
    def visit_binary_expr(self, expr):
        raise NotImplementedError

    @abstractmethod
    def visit_grouping_expr(self, expr):
        raise NotImplementedError

    @abstractmethod
    def visit_literal_expr(self, expr):
        raise NotImplementedError

    @abstractmethod
    def visit_unary_expr(self, expr):
        raise NotImplementedError


class Binary(Expr):
    def __init__(self, left: Expr, operator: Token, right: Expr):
        self.left = left
        self.operator = operator
        self.right = right

    def accept(self, visitor: IVisitor):
        return visitor.visit_binary_expr(self)


class Grouping(Expr):
    def __init__(self, expression: Expr):
        self.expression = expression

    def accept(self, visitor: IVisitor):
        return visitor.visit_grouping_expr(self)


class Literal(Expr):
    def __init__(self, value: object):
        self.value = value

    def accept(self, visitor: IVisitor):
        return visitor.visit_literal_expr(self)


class Unary(Expr):
    def __init__(self, operator: Token, right: Expr):
        self.operator = operator
        self.right = right

    def accept(self, visitor: IVisitor):
        return visitor.visit_unary_expr(self)