def infix_to_suffix(self):
op_stack = Stack()
for element in self.exp_elements_infix:
if element == Const.Pow or element == Const.LeftBracket:
# 左括号和乘方必定入栈
op_stack.push(element)
elif element == Const.Mul or element == Const.Div:
# 乘除法需要弹出乘方与乘除
while op_stack.size() > 0 and \
(op_stack.peek() == Const.Mul or op_stack.peek() == Const.Div or op_stack.peek() == Const.Pow):
op = op_stack.pop()
self.exp_elements_suffix.append(op)
op_stack.push(element)
elif element == Const.Plus or element == Const.Sub:
while op_stack.size() > 0 and (op_stack.peek() !=
Const.LeftBracket):
op = op_stack.pop()
self.exp_elements_suffix.append(op)
op_stack.push(element)
elif element == Const.RightBracket:
while op_stack.peek() != Const.LeftBracket:
op = op_stack.pop()
self.exp_elements_suffix.append(op)
op_stack.pop()
else:
self.exp_elements_suffix.append(element)
while op_stack.size() > 0:
self.exp_elements_suffix.append(op_stack.pop())
def test_peek(self):
s = Stack()
self.assertRaises(IndexError, s.peek)
s.push(0)
self.assertEqual(s.peek(), 0)
s.push(1)
self.assertEqual(s.peek(), 1)
s.pop()
self.assertNotEqual(s.peek(), 1)
def test_push(self):
s = Stack()
self.assertTrue(s.is_empty())
s.push('a')
self.assertFalse(s.is_empty())
for i in range(50):
n = random.randint(0, 1000)
s.push(n)
self.assertEqual(s.peek(), n)
def analize(self):
check = 1
initialStack = Stack()
workingStack = Stack()
output = []
initialStack.push(')')
initialStack.push('a')
initialStack.push('+')
initialStack.push('a')
initialStack.push('(')
initialStack.push('*')
initialStack.push('a')
workingStack.push(self.grammar.startingSymbol)
while not initialStack.isEmpty():
print(workingStack)
print(initialStack)
print(self.grammar.table[(workingStack.peek(), initialStack.peek())])
if workingStack.peek() == 'e':
workingStack.pop()
if self.grammar.table[(workingStack.peek(), initialStack.peek())][0] == 'pop':
workingStack.pop()
initialStack.pop()
else:
if len(self.grammar.table[(workingStack.peek(), initialStack.peek())]) > 0:
l = copy.deepcopy(self.grammar.table[(workingStack.peek(), initialStack.peek())][0][0])
print(l)
nr = self.grammar.table[(workingStack.peek(), initialStack.peek())][0][1]
print(nr)
workingStack.pop()
while l:
workingStack.push(l[-1])
del l[-1]
output.append(nr)
else:
check=0
print("error")
break
while not workingStack.isEmpty() and check == 1:
output.append(self.grammar.table[(workingStack.peek(), 'e')][0][1])
workingStack.pop()
print(output)