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memory.py
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memory.py
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class Memory:
def __init__(self, size=10, basic_state=""):
if size < 5:
size = 5
self.size = size
self.pointer = 0
self.bottom = size - 1
self.top = 1
self.states = [None] * size
self.states[0] = basic_state
def after(self, index):
return (index + 1) % self.size
def before(self, index):
return (index - 1) % self.size
def add(self, state):
self.pointer = self.after(self.pointer)
self.states[self.pointer] = state
if self.pointer == self.top:
self.top = self.after(self.top)
if self.top == self.bottom:
self.bottom = self.after(self.bottom)
def undo(self):
state = self.states[self.pointer]
self.pointer = self.before(self.pointer)
if self.pointer == self.bottom:
self.pointer = self.after(self.pointer)
return state
state = self.states[self.pointer]
return state
def redo(self):
state = self.states[self.pointer]
self.pointer = self.after(self.pointer)
if self.pointer == self.top:
self.pointer = self.before(self.pointer)
return state
state = self.states[self.pointer]
return state
def __repr__(self):
message = ""
for state in self.states:
if state is None:
message += "_"
else:
message += "X"
message += "\n"
message += " " * self.pointer
message += "|\n"
message += "b:" + str(self.bottom)
message += " p:" + str(self.pointer)
message += " t:" + str(self.top)
return message