elif self.lex.token == '/':
self.lex.scan()
left = DivideNode(left, self.Term())
else:
raise SyntaxError
def Term(self):
if self.lex.token == 'num':
leaf = NumNode(self.lex.match('num'))
return leaf
elif self.lex.token == 'var':
leaf = VarNode(self.lex.value, self.lex.start)
self.lex.scan()
return leaf
elif self.lex.token == '(':
self.lex.scan()
tree = self.Expr()
self.lex.match(')')
return tree
else:
raise SyntaxError
####################################################
# self-test code: use my parser, parser1's tester
####################################################
if __name__ == '__main__':
import testparser
testparser.test(Parser, 'parser2') # run with Parser class here
left = left * self.Term()
elif self.lex.token == '/':
self.lex.scan()
left = left / self.Term()
else:
raise SyntaxError
def Term(self):
if self.lex.token == 'num':
val = self.lex.match('num') # numbers
return val
elif self.lex.token == 'var':
if self.vars.has_key(self.lex.value):
val = self.vars[self.lex.value] # lookup name's value
self.lex.scan()
return val
else:
raise UndefinedError, self.lex.value
elif self.lex.token == '(':
self.lex.scan()
val = self.Expr() # sub-expression
self.lex.match(')')
return val
else:
raise SyntaxError
if __name__ == '__main__':
import testparser # self-test code
testparser.test(Parser, 'parser1') # test local Parser
self.lex.scan()
left = left * self.Term()
elif self.lex.token == '/':
self.lex.scan()
left = left / self.Term()
else:
raise SyntaxError()
def Term(self):
if self.lex.token == 'num':
val = self.lex.match('num') # numbers
return val
elif self.lex.token == 'var':
if self.lex.value in self.vars.keys(): # keys(): EIBTI!
val = self.vars[self.lex.value] # look up name's value
self.lex.scan()
return val
else:
raise UndefinedError(self.lex.value)
elif self.lex.token == '(':
self.lex.scan()
val = self.Expr() # sub-expression
self.lex.match(')')
return val
else:
raise SyntaxError()
if __name__ == '__main__':
import testparser # self-test code
testparser.test(Parser, 'parser1') # test local Parser
elif self.lex.token == '/':
self.lex.scan()
left = DivideNode(left, self.Term())
else:
raise SyntaxError
def Term(self):
if self.lex.token == 'num':
leaf = NumNode(self.lex.match('num'))
return leaf
elif self.lex.token == 'var':
leaf = VarNode(self.lex.value, self.lex.start)
self.lex.scan()
return leaf
elif self.lex.token == '(':
self.lex.scan()
tree = self.Expr()
self.lex.match(')')
return tree
else:
raise SyntaxError
####################################################
# self-test code: use my parser, parser1's tester
####################################################
if __name__ == '__main__':
import testparser
testparser.test(Parser, 'parser2') # run with Parser class here
self.lex.scan()
left = DivideNode(left, self.Term())
else:
raise SyntaxError()
def Term(self):
if self.lex.token == "num":
leaf = NumNode(self.lex.match("num"))
return leaf
elif self.lex.token == "var":
leaf = VarNode(self.lex.value, self.lex.start)
self.lex.scan()
return leaf
elif self.lex.token == "(":
self.lex.scan()
tree = self.Expr()
self.lex.match(")")
return tree
else:
raise SyntaxError()
#################################################################################
# self-test code: use my parser, parser1's tester
#################################################################################
if __name__ == "__main__":
import testparser
testparser.test(Parser, "parser2") # run with Parser class here
