[nothrabannosir]

Isn't strict mode purely semantical? IIRC you can implement a use strict pass purely on the AST, after the parser.

It's not an excuse, of course.

[david-given]

Bah. You're absolutely right, of course, that's why strict mode won't help.

Now I find myself wishing there was a stricter mode. <script type="text/sensible-javascript">, perhaps...