TypeError being thrown in tree view on online parser test

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Go to esprima.org/demo/parse.html
2. Click the tab "Tree" (no other interaction needed)

What is the expected output?
No error thrown

What do you see instead?
A red bar saying "TypeError: undefined is not a function"

What version of the product are you using? On what operating system? Which
browser?
Chrome 38.0.2125.44 (Beta channel)

Please provide any additional information below.
The error never clears itself after it is thrown. It does reset on source edit 
while either the "Syntax" or "Tokens" tabs are selected.

Here's the stack trace I got out of Chrome (by injecting a `console.log`):

TypeError: undefined is not a function
    at window.updateTree (http://esprima.org/demo/parse.js:49:20)
    at http://esprima.org/demo/parse.js:193:24

It looks like it's complaining about the `Y.TreeView` call, if I read it right.

Original issue reported on code.google.com by impinball on 14 Sep 2014 at 3:16

[GoogleCodeExporter]

It works just fine. The error may indicate that the tree component failed to 
load (perhaps server issue).

Try to reload the page again.

Original comment by ariya.hi...@gmail.com on 9 Oct 2014 at 7:19

• Changed state: Invalid

[GoogleCodeExporter]

I filed this a long time ago. It may have already been resolved.

Original comment by impinball on 9 Oct 2014 at 7:22