def convert_postfix_to_tree(stat):
stack = []
r = re.compile('(~|&|\||=>|[A-Z][A-Z])')
preds = r.findall(stat)
for token in preds:
if token in [operator['and'], operator['or'], operator['implies']]:
operand2 = stack.pop()
operand1 = stack.pop()
op = DOM(token, preds_map)
op.left = operand1
op.right = operand2
stack.append(op)
elif token == operator['neg']:
stack[-1].negated = not stack[-1].negated
else:
operand = DOM(token, preds_map)
stack.append(operand)
return stack[0]
def distribute_and_over_or(self, dom, preds_map):
if dom:
if dom.val == self.operator['or']:
if dom.left.val == self.operator[
'and'] and dom.right.val == self.operator['and']:
left_and, right_and = dom.left, dom.right
a, b, c, d = left_and.left, left_and.right, right_and.left, right_and.right
a_copy, b_copy, c_copy, d_copy = copy.deepcopy(
a), copy.deepcopy(b), copy.deepcopy(c), copy.deepcopy(
d)
left_or_1 = DOM(self.operator['or'], preds_map)
left_or_2 = DOM(self.operator['or'], preds_map)
right_or_1 = DOM(self.operator['or'], preds_map)
right_or_2 = DOM(self.operator['or'], preds_map)
dom.val = self.operator['and']
left_and.left, left_and.right, right_and.left, right_and.right = left_or_1, left_or_2, right_or_1, right_or_2
left_or_1.left, left_or_1.right = a, c
left_or_2.left, left_or_2.right = a_copy, d
right_or_1.left, right_or_1.right = b, c_copy
right_or_2.left, right_or_2.right = b_copy, d_copy
elif dom.left.op and not dom.right.op and dom.left.val == self.operator[
'and']:
c, a = dom.left.right, a = dom.right
a_copy = copy.deepcopy(a)
right_or = DOM(self.operator['or'], preds_map)
dom.val = self.operator['and']
dom.left.val = self.operator['or']
dom.left.right = a
dom.right = right_or
right_or.left, right_or.right = c, a_copy
elif not dom.left.op and dom.right.op and dom.right.val == self.operator[
'and']:
a = dom.left
a_copy = copy.deepcopy(a)
b = dom.right.left
left_or = DOM(self.operator['or'], preds_map)
dom.val = self.operator['and']
dom.right.val = self.operator['or']
dom.left = left_or
left_or.left, left_or.right = a, b
dom.right.left = a_copy
self.distribute_and_over_or(dom.left, preds_map)
self.distribute_and_over_or(dom.right, preds_map)
