levenshtein function

int levenshtein(String s, String t, { bool caseSensitive = true, })

Levenshtein algorithm implementation based on: http://en.wikipedia.org/wiki/Levenshtein_distance#Iterative_with_two_matrix_rows

Implementation

int levenshtein(String s, String t, {bool caseSensitive = true}) {
  if (!caseSensitive) {
    // ignore: parameter_assignments
    s = s.toLowerCase();
    // ignore: parameter_assignments
    t = t.toLowerCase();
  }
  if (s == t) return 0;
  if (s.isEmpty) return t.length;
  if (t.isEmpty) return s.length;

  final v0 = List<int>.filled(t.length + 1, 0);
  final v1 = List<int>.filled(t.length + 1, 0);

  for (var i = 0; i < t.length + 1; i < i++) {
    v0[i] = i;
  }

  for (var i = 0; i < s.length; i++) {
    v1[0] = i + 1;

    for (var j = 0; j < t.length; j++) {
      final cost = (s[i] == t[j]) ? 0 : 1;
      v1[j + 1] = math.min(v1[j] + 1, math.min(v0[j + 1] + 1, v0[j] + cost));
    }

    for (var j = 0; j < t.length + 1; j++) {
      v0[j] = v1[j];
    }
  }

  return v1[t.length];
}