(chibi edit-distance)

(edit-distance s1 s2)

Returns the levenshtein distance between s1 and s2 - a cost of 1 per character insertion, deletion or update. Runs in quadratic time and linear memory.
(edit-distance "same" "same")
=> 0
(edit-distance "same" "sand")
=> 2
(edit-distance "Saturday" "Sunday")
=> 3

(find-nearest-edits str str-ls [max-distance])

Returns a list of strings in str-ls with the smallest edit distance to str, preserving order. If max-distance is provided and positive, only return if the edits are less or equal to that distance.