T9 blogpost - 4

gistfile1.js

function traverseAddingNodes(node) {
  var i = 0, len = word.length;
  // Traverse the tree's existing nodes as far as possible.
  for(i, len; i < len; i++) {
    var thisLetter = word[i];
    var thisKey = keys[thisLetter];

    if(node.children.hasOwnProperty(thisKey)) {
      node = node.children[thisKey];
    } else { break; }
  }
  
  // If we reach this point and we still aren't at the node we want, it
  // means that other words matching this key pattern haven't been
  // inserted before. Continue, this time adding the required nodes 
  // as we go.
  for(i, len; i < len; i++) {
    thisLetter = word[i];
    thisKey = keys[thisLetter];
    node.children[thisKey] = new Trie();
    node = node.children[thisKey];
  }

  return node;
}