def term(self):
r = None
n = self.factor()
if self.tkr.cur() in ['*', '/']:
r = Node()
r.val = self.tkr.get()
if r.val == '*':
r.type = 'mul'
else:
r.type = 'div'
r.rhs = n
r.lhs = self.term()
else:
r = n
return r
def expr(self):
r = None
n = self.term()
if self.tkr.cur() in ['+', '-']:
r = Node()
r.val = self.tkr.get()
if r.val == '+':
r.type = 'add'
else:
r.type = 'sub'
r.rhs = n
r.lhs = self.expr()
else:
r = n
return r
def factor(self):
n = None
if self.tkr.cur() == '(':
self.tkr.get()
n = self.expr()
self.tkr.get()
else:
n = Node()
n.val = int(self.tkr.get())
n.type = 'number'
return n