if self.accept_test():
raise Accept()
raise Reject("Unexpected character")
def on_reject(self, exc):
super().on_reject(exc)
self.error_msg = exc.args[0]
if __name__ == '__main__':
from io import StringIO
from pycog.utility.diagram import diagram
with open("ps_and_qs.gv", "w") as gv_file:
diagram(PsAndQs(StringIO("pppqqq")), gv_file)
def report(fsm):
accepted = fsm.run()
if accepted:
print('"{inp}" accepted.'.format(inp = fsm.stream.getvalue()))
else:
ptr = ' '*fsm.pos + '^'
inp = fsm.stream.getvalue()
msg = 'Rejected: {msg}\n{inp}\n{ptr}'.format(msg=fsm.error_msg,
inp=inp, ptr=ptr)
print(msg)
print('-'*60)
print("NFA to accept the language (p^i)(q^j)")
print('='*60)
def on_no_transition(self, s_name):
if self.accept_test():
raise Accept()
self.error_msg = "No transition available--unknown cause."
if not self.stack_empty:
self.unmatched_open()
super().on_no_transition(s_name)
if __name__ == '__main__':
from io import StringIO
from pycog.utility.diagram import diagram
with open("check_parens.gv", "w") as gv_file:
diagram(ParenChecker(StringIO("()")), gv_file)
def report(fsm):
try:
accepted = fsm.run()
if accepted:
print('"{inp}" accepted.'.format(inp = fsm.stream.getvalue()))
else:
inp = fsm.stream.getvalue()
ptr = ""
if fsm.open_symbol_pos != None:
ptr = ' '*fsm.open_symbol_pos + '^'
if fsm.close_symbol_pos != None:
ptr += ' '*(fsm.close_symbol_pos - fsm.open_symbol_pos
- 1) + '^'
elif fsm.close_symbol_pos != None:
sys.stdout.write('\n')
def on_backtrack(self, occ):
"""Undo the placing of a queen in response to backtracking."""
super().on_backtrack(occ)
# Uncomment these two lines to display the state of the board each time
# backtracking occurs.
# print()
# self.draw()
if occ.state not in ['init', 'final']:
self.queens.remove(self.current_state)
def on_exhausted(self):
"""
Handle the case where no solution can be found.
This should never happen.
"""
raise Exception("No solution found!")
if __name__ == "__main__":
solver = EightQueens()
solver.run()
solver.draw()
with open("eight_queens.gv", "w") as gv_file:
diagram(solver, gv_file)
sys.stdout.write('\n')
def on_backtrack(self, occ):
"""Undo the placing of a queen in response to backtracking."""
super().on_backtrack(occ)
# Uncomment these two lines to display the state of the board each time
# backtracking occurs.
# print()
# self.draw()
if occ.state not in ['init', 'final']:
self.queens.remove(self.current_state)
def on_exhausted(self):
"""
Handle the case where no solution can be found.
This should never happen.
"""
raise Exception("No solution found!")
if __name__ == "__main__":
solver = EightQueens()
solver.run()
solver.draw()
with open("eight_queens.gv", "w") as gv_file:
diagram(solver, gv_file)
raise Accept()
raise Reject("Unexpected character")
def on_reject(self, exc):
super().on_reject(exc)
self.error_msg = exc.args[0]
if __name__ == '__main__':
from io import StringIO
from pycog.utility.diagram import diagram
with open("ps_and_qs.gv", "w") as gv_file:
diagram(PsAndQs(StringIO("pppqqq")), gv_file)
def report(fsm):
accepted = fsm.run()
if accepted:
print('"{inp}" accepted.'.format(inp=fsm.stream.getvalue()))
else:
ptr = ' ' * fsm.pos + '^'
inp = fsm.stream.getvalue()
msg = 'Rejected: {msg}\n{inp}\n{ptr}'.format(msg=fsm.error_msg,
inp=inp,
ptr=ptr)
print(msg)
print('-' * 60)
print("NFA to accept the language (p^i)(q^j)")
