package mula

start ~k ~str produces the starting state of the automaton for edit distance k. Here k must not be negative and must not be greater (Sys.int_size - 1) / 2.

feed nfa ch produces a new state where the automaton has been fed the character ch.

current_error nfa produces Some n if the current error count recorded by the nfa is a number n, or None if the error count is larger than the limit k that the nfa was started with. current_error nfa may be smaller than end_input nfa, since it does not account for delete operations at the end of the fed string.

end_input nfa computes the edit distance between the starting string and the string fed to nfa. It produces Some n if the edit distance in a number n that is less than the limit k that the automaton was started with, and None otherwise.

feed_str nfa ~str produces a new state where the automaton has been fed the characters from the string str.

get_distance ~k str1 str2 computes the edit distance between two strings. It creates an automaton with limit k and str1, and then feeds it the string str2, and thet outputs the result of calling end_input on the nfa.