Function extractSourceSpans

docs/js/google-code-prettify.js:519–565

* Split markup into a string of source code and an array mapping ranges in * that string to the text nodes in which they appear. * * * The HTML DOM structure: * * (Element "p" * (Element "b" * (Text "print ")) ; #1 * (Text "'Hello '")

(node, isPreformatted)

   * @return {Object} source code and the text nodes in which they occur.
   */
  function extractSourceSpans(node, isPreformatted) {
    var nocode = /(?:^|\s)nocode(?:\s|$)/;
  
    var chunks = [];
    var length = 0;
    var spans = [];
    var k = 0;
  
    function walk(node) {
      switch (node.nodeType) {
        case 1:  // Element
          if (nocode.test(node.className)) { return; }
          for (var child = node.firstChild; child; child = child.nextSibling) {
            walk(child);
          }
          var nodeName = node.nodeName.toLowerCase();
          if ('br' === nodeName || 'li' === nodeName) {
            chunks[k] = '\n';
            spans[k << 1] = length++;
            spans[(k++ << 1) | 1] = node;
          }
          break;
        case 3: case 4:  // Text
          var text = node.nodeValue;
          if (text.length) {
            if (!isPreformatted) {
              text = text.replace(/[ \t\r\n]+/g, ' ');
            } else {
              text = text.replace(/\r\n?/g, '\n');  // Normalize newlines.
            }
            // TODO: handle tabs here?
            chunks[k] = text;
            spans[k << 1] = length;
            length += text.length;
            spans[(k++ << 1) | 1] = node;
          }
          break;
      }
    }
  
    walk(node);
  
    return {
      sourceCode: chunks.join('').replace(/\n$/, ''),
      spans: spans
    };
  }


  /**