def primary(self):
expr = None
token_value = self.tokens[self.c_tok].value
if self.match('ENDLINE'):
self.c_tok -= 1
expr = Expr.Literal(None)
elif self.match('TRUE'): expr = Expr.Literal(True)
elif self.match('FALSE'): expr = Expr.Literal(False)
elif self.match('NIL'): expr = Expr.Literal(None)
elif self.match('STRING'): expr = Expr.Literal(token_value[1:len(token_value)-1])
elif self.match('NUM'): expr = Expr.Literal(float(token_value))
elif self.match('KIND'): expr = Expr.Literal(token_value)
elif self.match('ID'): expr = Expr.Variable(token_value)
elif self.match('L_PAREN'):
self.c_tok += 1
expr = Expr.Grouping(self.expression())
if not self.match('R_PAREN'):
raise Parser.ParserError
if not expr:
raise Parser.ParserError
self.c_tok += 1
return expr
def multiplication(self):
expr = self.exponentiation()
while self.match('STAR', 'SLASH', 'MOD'):
operator = self.tokens[self.c_tok].value
self.c_tok += 1
right = self.exponentiation()
expr = Expr.Listed(operator, [expr, right])
return expr
self.c_tok += 1
return Expr.Literal(self.tokens[self.c_tok - 1].value)
def addition(self):
expr = self.multiplication()
while self.match('PLUS', 'MINUS'):
operator = self.tokens[self.c_tok].value
self.c_tok += 1
right = self.multiplication()
expr = Expr.Listed(operator, [expr, right])
return expr
self.c_tok += 1
return Expr.Literal(self.tokens[self.c_tok - 1].value)
