y = 0
undo = Stack()
text = Stack()
form = DoublyLinkedList()
while True:
line = fileIn.readline().split()
if line == []:
break
elif line[0].lower() == 'adicionar':
undo.clean_out()
for i in range(1, len(line)):
text.push(line[i])
elif line[0].lower() == 'italico' or line[0].lower() == 'negrito':
if form.isEmpty() is True:
form.insertAtEnd(line[0].lower())
else:
s = form.search(line[0].lower())
if s is None:
form.insertAtEnd(line[0].lower())
else:
form.removeNode(line[0].lower())
elif line[0].lower() == 'apagar':
y = int(line[1])
for i in range(y):
x = text.pop()
undo.push(x)
elif line[0].lower() == 'desfazer':
x = undo.pop()
while x is not None:
text.push(x)
