def language_equivalence_automaton(student_answer, other, length):
try:
A = parse_pda(student_answer)
except RuntimeError as e:
return {'correct': False, 'feedback': str(e)}
A_words = generate_language(A, length)
B = parse_pda(other)
B_words = generate_language(B, length)
feedback = compare_languages(A_words, B_words)
if len(feedback) == 0:
return {'correct': True}
else:
return {'correct': False, 'feedback': " / ".join(feedback)}
def state_count(student_answer, max_states):
try:
A = parse_pda(student_answer)
except RuntimeError as e:
return {'correct': False,
'feedback': str(e)}
num_states = len(A.Q)
if num_states <= max_states:
return {'correct': True}
else:
return {'correct': False,
'feedback': "You used too many states (at most " +
str(max_states) + " allowed)"}
def language_equivalence_words(student_answer, word_list, length):
word_list = " ".join(word_list)
try:
A = parse_pda(student_answer)
except RuntimeError as e:
return {'correct': False, 'feedback': str(e)}
A_words = generate_language(A, length)
words = parse_word_list(word_list)
feedback = compare_languages(A_words, words)
if len(feedback) == 0:
return {'correct': True}
else:
return {'correct': False, 'feedback': " / ".join(feedback)}
def pda_rejects(student_answer, word_list):
try:
A = parse_pda(student_answer)
except RuntimeError as e:
return {'correct': False,
'feedback': str(e)}
word_list = " ".join(word_list)
words = parse_word_list(word_list)
for word in words:
if pda_accepts_word(A, word):
return {'correct': False,
'feedback': 'a word was accepted',
'word': word}
return {'correct': True,
'feedback': 'correct'}