Subj : Re: Rhino 1.5R4_1 problem with try/catch, WITH, GETBASE
To   : Brendan Eich <brendan@meer.net>
From : Laura Werner <lwerner@bevocal.com>
Date : Mon Jun 09 2003 03:35 pm

Thanks for the response, Brendan!


> Why don't all scopes other than the global one you describe below 
> descend via parent from the global scope?

They do; I must not have described it correctly.  For example, it might 
look like this

Global Scope
      ^
      | parent
      |
Application
    Scope
      ^
      | parent
      |
   Document
    Scope
      ^
      | parent
      |
    Form
    Scope

etc.

> Why does each script need its own scope object to execute?  Is that part 
> of the VXML DOM spec?

I explained this poorly too, I guess.  When I execute the script, I pass 
in the currently active VXML scope.  For example, when a form-level 
script is activated during form initialization, I pass in the "Form 
Scope" from the diagram above.  Its parent chain leads up to the global 
scope.

The problem happens if one of the functions in the script has a "with" 
or "try/catch".  In that case, the "calleeScope" variable in 
Interpreter.interpret() gets set to the result of getTopLevelScope() 
(which is "Global Scope"), and references to other items defined in the 
script don't work (or other items in Form Scope if that's where the 
script is).

I hope this is more clear.

-- Laura

.