How to escape implicit 'with (this)' of a method body

[P T Withington]

On 2008-07-31, at 12:34EDT, Peter Hall wrote:

>> Here's my take at an example of brittleness:
>>
>> var bar = 42;
>>
>> class foo {
>>  function zot () { return bar; }
>> }
>>
>> ...
>>
>> class subfoo extends foo {
>>  var bar = 'oops!';
>> }
>>
>> (new foo).zot() => 42
>> (new myfoo).zot() => ?
>
>
> In AS3, the reference to bar in the zot function would be bound to
> this.bar

I don't follow.  There is no `this.bar` in the class where zot is  
defined.

> so, even in the subclass, there is no ambiguity and both
> cases would output 42. I assume that ES4 would follow this behaviour.
>
> The fragility is more likely to be in the opposite situation, where a
> method in a class intends to access a global variable, but the
> superclass has declared it too.

That was my original example, which would also exhibit fragility if  
the superclass is developed/evolves independently.  In either case,  
the fragility stems from the implicit (unreformed) `with this` in  
method bodies.