Function numberLines

docs/js/google-code-prettify.js:969–1095

* Given a DOM subtree, wraps it in a list, and puts each line into its own * list item. * * @param {Node} node modified in place. Its content is pulled into an * HTMLOListElement, and each line is moved into a separate list item. * This requires cloning elements, so the input

(node, opt_startLineNum, isPreformatted)

   *     be treated as significant.
   */
  function numberLines(node, opt_startLineNum, isPreformatted) {
    var nocode = /(?:^|\s)nocode(?:\s|$)/;
    var lineBreak = /\r\n?|\n/;
  
    var document = node.ownerDocument;
  
    var li = document.createElement('li');
    while (node.firstChild) {
      li.appendChild(node.firstChild);
    }
    // An array of lines.  We split below, so this is initialized to one
    // un-split line.
    var listItems = [li];
  
    function walk(node) {
      switch (node.nodeType) {
        case 1:  // Element
          if (nocode.test(node.className)) { break; }
          if ('br' === node.nodeName) {
            breakAfter(node);
            // Discard the <BR> since it is now flush against a </LI>.
            if (node.parentNode) {
              node.parentNode.removeChild(node);
            }
          } else {
            for (var child = node.firstChild; child; child = child.nextSibling) {
              walk(child);
            }
          }
          break;
        case 3: case 4:  // Text
          if (isPreformatted) {
            var text = node.nodeValue;
            var match = text.match(lineBreak);
            if (match) {
              var firstLine = text.substring(0, match.index);
              node.nodeValue = firstLine;
              var tail = text.substring(match.index + match[0].length);
              if (tail) {
                var parent = node.parentNode;
                parent.insertBefore(
                    document.createTextNode(tail), node.nextSibling);
              }
              breakAfter(node);
              if (!firstLine) {
                // Don't leave blank text nodes in the DOM.
                node.parentNode.removeChild(node);
              }
            }
          }
          break;
      }
    }
  
    // Split a line after the given node.
    function breakAfter(lineEndNode) {
      // If there's nothing to the right, then we can skip ending the line
      // here, and move root-wards since splitting just before an end-tag