DamerauLevenshtein
class DamerauLevenshtein
Damerau-Levenshtein distance with transposition (unrestricted Damerau-Levenshtein distance).
The distance is the minimum number of operations needed to transform one string into the other, where an operation is defined as an insertion, deletion, or substitution of a single character, or a transposition of two adjacent characters. It does respect triangle inequality, and is thus a metric distance.