def main():
""" Print test expression """
expression = loxExprAST.Binary(
loxExprAST.Unary(
loxtoken.Token(loxtoken.TokenType.MINUS, "-", None, 1),
loxExprAST.Literal(123)),
loxtoken.Token(loxtoken.TokenType.STAR, "*", None, 1),
loxExprAST.Grouping(loxExprAST.Literal(45.67)))
print(ASTPrinter().print(expression))
def multiplication(self) -> loxExprAST.Expr:
""" multiplication → unary ( ( "/" | "*" ) unary )* """
expr: loxExprAST.Expr = self.unary()
while self.match(Parser.tokentypes.SLASH, Parser.tokentypes.STAR):
operator: loxtoken.Token = self.previous()
right_expr: loxExprAST.Expr = self.unary()
expr = loxExprAST.Binary(expr, operator, right_expr)
return expr
def addition(self) -> loxExprAST.Expr:
""" addition → multiplication ( ( "-" | "+" ) multiplication )* """
expr: loxExprAST.Expr = self.multiplication()
while self.match(Parser.tokentypes.MINUS, Parser.tokentypes.PLUS):
operator: loxtoken.Token = self.previous()
right_expr: loxExprAST.Expr = self.multiplication()
expr = loxExprAST.Binary(expr, operator, right_expr)
return expr
def equality(self) -> loxExprAST.Expr:
""" equality → comparison ( ( "!=" | "==" ) comparison )* """
expr: loxExprAST.Expr = self.comparison()
while self.match(Parser.tokentypes.BANG_EQUAL,
Parser.tokentypes.EQUAL_EQUAL):
operator: loxtoken.Token = self.previous()
right_expr: loxExprAST.Expr = self.comparison()
expr = loxExprAST.Binary(expr, operator, right_expr)
return expr
def comparison(self) -> loxExprAST.Expr:
""" comparison → addition ( ( ">" | ">=" | "<" | "<=" ) addition )* """
expr: loxExprAST.Expr = self.addition()
while self.match(Parser.tokentypes.GREATER,
Parser.tokentypes.GREATER_EQUAL,
Parser.tokentypes.LESS, Parser.tokentypes.LESS_EQUAL):
operator: loxtoken.Token = self.previous()
right_expr: loxExprAST.Expr = self.addition()
expr = loxExprAST.Binary(expr, operator, right_expr)
return expr