def exclusiveOr(expr):
exclusiveList = []
temp = []
for char in expr:
if (char == '|'):
exclusiveList.append(temp)
temp = []
continue
temp.append(char)
exclusiveList.append(temp)
#build FA in each elements in list
faList = []
for expr in exclusiveList:
faList.append(exprToFA(expr))
counter = 1
list_end_subFA = []
fa = FA({0}, set(), {}, 0, {0})
fa.delta[(fa.q0, '')] = set() #to prevent key error
for sub_fa in faList:
subFA = sub_fa.copy()
subFA.Q = {i + counter for i in subFA.Q}
new_delta = {}
#update delta of subFA
for i in subFA.delta:
new_delta[(i[0] + counter,
i[1])] = {j + counter
for j in subFA.delta[i]}
subFA.delta = new_delta
#update all attr of SubFA
subFA.q0 += counter
subFA.F = {list(subFA.F)[0] + counter}
#join sigma and Q
fa.Sigma = fa.Sigma | subFA.Sigma
fa.Q = fa.Q | subFA.Q
#connect transition
fa.delta[(fa.q0, '')].add(subFA.q0) #add empty move to join 2 FA
fa.delta = {**fa.delta, **subFA.delta} #combine dict
list_end_subFA.append(list(subFA.F)[0]) #keep end state(s)
#update counter
counter = len(fa.Q)
#connect to same end state
fa.Q.add(counter)
for end in list_end_subFA: #set new end state
fa.delta[(end, '')] = {counter}
fa.F = {counter}
return fa.copy()
def exprToFA(expr_list):
fa = FA({0}, set(), {}, 0, {0})
if ('*' in expr_list):
return star(expr_list[0])
elif ('|' in expr_list):
return exclusiveOr(expr_list)
for char in expr_list:
if (type(char) == type(FA())):
fa = join(fa, char)
else:
fa = concat(fa, char)
return fa.copy()