int _editDistance()

in lib/command_runner.dart [505:538]

• 26 lines of code
• 12 McCabe index (conditional complexity)

int _editDistance(String from, String to) {
  // Add a space in front to mimic indexing by 1 instead of 0.
  from = ' $from';
  to = ' $to';
  var distances = [
    for (var i = 0; i < from.length; i++)
      [
        for (var j = 0; j < to.length; j++)
          if (i == 0) j else if (j == 0) i else 0,
      ],
  ];

  for (var i = 1; i < from.length; i++) {
    for (var j = 1; j < to.length; j++) {
      // Removals from `from`.
      var min = distances[i - 1][j] + 1;
      // Additions to `from`.
      min = math.min(min, distances[i][j - 1] + 1);
      // Substitutions (and equality).
      min = math.min(
          min,
          distances[i - 1][j - 1] +
              // Cost is zero if substitution was not actually necessary.
              (from[i] == to[j] ? 0 : 1));
      // Allows for basic swaps, but no additional edits of swapped regions.
      if (i > 1 && j > 1 && from[i] == to[j - 1] && from[i - 1] == to[j]) {
        min = math.min(min, distances[i - 2][j - 2] + 1);
      }
      distances[i][j] = min;
    }
  }

  return distances.last.last;
}