def levenshtein_automata(term, k):
nfa = NFA((0, 0))
for i, c in enumerate(term):
for e in range(k + 1):
# Correct character
nfa.add_transition((i, e), c, (i + 1, e))
if e < k:
# Insertion
nfa.add_transition((i, e), NFA.ANY, (i, e + 1))
# Deletion
nfa.add_transition((i, e), NFA.EPSILON, (i + 1, e + 1))
# Substitution
nfa.add_transition((i, e), NFA.ANY, (i + 1, e + 1))
for e in range(k + 1):
if e < k:
nfa.add_transition((len(term), e), NFA.ANY, (len(term), e + 1))
nfa.add_final_state((len(term), e))
return nfa
def levenshtein_automata(tokens, k):
l = len(tokens)
nfa = NFA(states=set(range((l + 1) * (k + 1))))
# Insert forward edges
for i in range(l):
for j in range(k + 1):
nfa.add_transition((j * (l + 1)) + i, (j * (l + 1)) + i + 1,
tokens[i])
# Insert lifting edges
for row in range(k):
for col in range(l + 1):
nfa.add_transition((row * (l + 1)) + col,
((row + 1) * (l + 1)) + col, WILDCARD)
# Insert Diagnol
for row in range(k):
for col in range(l):
nfa.add_transition((row * (l + 1)) + col,
((row + 1) * (l + 1)) + col + 1, EPSILON)
nfa.add_transition((row * (l + 1)) + col,
((row + 1) * (l + 1)) + col + 1, WILDCARD)
nfa.set_start(0)
for i in range(k + 1):
nfa.make_final(i * (l + 1) + l)
nfa.normalize()
return nfa
