def _validate_transition_invalid_stack_symbols(self, start_state,
stack_symbol):
"""Raise an error if transition stack symbols are invalid."""
if stack_symbol not in self.stack_symbols:
raise exceptions.InvalidSymbolError(
'state {} has invalid transition stack symbol {}'.format(
start_state, stack_symbol))
def _validate_transition_invalid_symbols(self, start_state, paths):
"""Raise an error if transition input symbols are invalid."""
for input_symbol in paths.keys():
if input_symbol not in self.input_symbols:
raise exceptions.InvalidSymbolError(
'state {} has invalid transition symbol {}'.format(
start_state, input_symbol))
def _validate_transition_invalid_input_symbols(self, start_state,
input_symbol):
"""Raise an error if transition input symbols are invalid."""
if input_symbol not in self.input_symbols and input_symbol != 'ε':
raise exceptions.InvalidSymbolError(
'state {} has invalid transition input symbol {}'.format(
start_state, input_symbol))
def _validate_initial_stack_symbol(self):
"""Was CHANGED Raise an error if initial stack symbol is invalid."""
for i in self.initial_stack_symbol:
if i not in self.stack_symbols:
raise exceptions.InvalidSymbolError(
'initial stack symbol {} is invalid'.format(
self.initial_stack_symbol))
def _validate_transition_symbols(self, state, paths):
for tape_symbol in paths.keys():
if tape_symbol not in self.tape_symbols:
raise exceptions.InvalidSymbolError(
'transition symbol {} for state {} is not valid'.format(
tape_symbol, state
)
)
def _validate_transition_result(self, result):
result_state, result_symbol, result_direction = result
if result_state not in self.states:
raise exceptions.InvalidStateError(
'result state is not valid ({})'.format(result_state))
if result_symbol not in self.tape_symbols:
raise exceptions.InvalidSymbolError(
'result symbol is not valid ({})'.format(result_symbol))
self._validate_transition_result_direction(result_direction)
def _validate_transition_invalid_symbols(self, start_state, paths):
for input_symbol in paths.keys():
if input_symbol not in self.input_symbols and input_symbol != '':
raise exceptions.InvalidSymbolError(
'state {} has invalid transition symbol {}'.format(
start_state, input_symbol))
def _validate_blank_symbol(self):
"""Raise an error if blank symbol is not a tape symbol."""
if self.blank_symbol not in self.tape_symbols:
raise exceptions.InvalidSymbolError(
'blank symbol {} is not a tape symbol'.format(
self.blank_symbol))
