Function countColumn

static/js/codemirror/codemirror.js:4923–4933

(string, end, tabSize)

  // Counts the column offset in a string, taking tabs into account.
  // Used mostly to find indentation.
  function countColumn(string, end, tabSize) {
    if (end == null) {
      end = string.search(/[^\s\u00a0]/);
      if (end == -1) end = string.length;
    }
    for (var i = 0, n = 0; i < end; ++i) {
      if (string.charAt(i) == "\t") n += tabSize - (n % tabSize);
      else ++n;
    }
    return n;
  }
  CodeMirror.countColumn = countColumn;

  var spaceStrs = [""];