def _validate_rpn(self):
counter = 0
for elem in self._res:
if elem.isdigit() or elem.text in ['x', 'X']:
counter += 1
elif elem.text in OPS and elem.text not in ['@', '#']:
counter -= 2
if counter < 0:
raise ValidateError("Чего-то тут не хватает", elem)
counter += 1
elif elem.text in ['@', '#']:
counter -= 1
if counter < 0:
raise ValidateError("Чего-то тут не хватает", elem)
counter += 1
if counter != 1:
raise ValidateError("Уравнение не корректно!")
def _handle_eos(self) \
-> None:
if self._moved_left:
self._handle_parentheses(Token(')', 0))
while not self._stack.is_empty():
val = self._stack_to_res()
if val.text == '(':
raise ValidateError("Brackets not balanced", val)
def _handle_parentheses(self, val: Token) \
-> None:
while not self._stack.is_empty():
if self._stack.is_bracket():
self._stack.pop()
return
self._stack_to_res()
raise ValidateError("Brackets not balanced", val)
def _add_token(self, token: Token) -> None:
if token.text in operations:
token = Node(token, NODE_OP)
elif token.text in unary_op:
token = Node(token, NODE_UNARY)
elif token.text in ['x', 'X']:
token = Node(token, NODE_VAR)
elif token.isdigit():
token = Node(token, NODE_NUM)
else:
raise ValidateError("Undefined token", token)
self._stack.push(token)
def select_action(self, val: Token) \
-> None:
if val.position >= self._position:
self._position = val.position
if val.text in OPS:
self._handle_operator(val)
elif val.text.isspace():
pass
elif val.isdigit():
if self._previous_token == ')':
self.select_action(Token('*', self._position))
self._res.append(val)
self._possible_unary = False
elif val.text in ['x', 'X']:
if self.__previous_is_digit() or \
self._previous_token in ['x', 'X'] or \
self._previous_token == ')':
self.select_action(Token('*', self._position))
self._res.append(val)
self._possible_unary = False
elif val.text == '(':
self.__increase_stack(val)
self._possible_unary = True
elif val.text == ')':
if self._previous_token in OPS:
raise ValidateError(
"Перед закрывающими скобками стоит "
"знак операции", val)
self._handle_parentheses(val)
self._possible_unary = False
elif val.text == '=':
if self._moved_left:
raise ValidateError("Not more than one quality sign allowed",
val)
self._handle_eos()
self._move_to_left()
self._possible_unary = True
else:
raise ValidateError(f"Unknown token '{val.text}'", val)
def create_tokens(equation: str) -> Generator:
pattern = re.compile(r"("
r"(?:[-+()])"
r"|(?:[\d.]+)"
r"|(?:[*/])"
r"|(?:[xX])"
r"|(?:\^)"
r"|(?:\s+)"
r"|(?:=)"
r")")
position: int = 0
while position < len(equation):
match_obj = pattern.match(equation, position)
if match_obj is None:
raise ValidateError("Символ не опознан. Уравнение не валидно.",
Token("", position))
text = match_obj.group(1)
yield Token(text, match_obj.start(1))
position = match_obj.end()
def pop(self) -> Node:
if self.is_empty():
raise ValidateError("Стак дерева пустой")
self._size -= 1
return self._stack.pop()