[Laszlo-dev] Previous results of debugger evals

[André Bargull]

So, should it be possible to access these shortcuts anywhere else than 
while eval'ing an expression and/or should it be possible to use them in 
complex expressions? At least according to the Lisp reference, it should 
be possible to use them in complex expressions, but that's currently 
only possible in swf8 and dhtml. And only in swf8, you can access the 
values globally, but that doesn't seem to be intended as you said below.
If Compiler#compileAndWriteToSWF() and Compiler#compileAndWriteToAS3() 
are changed to include `with (Debug.environment) { ... }`, it should be 
possible to use the shortcuts in complex expressions and avoid polluting 
the global namespace. These changes seem to be quite easy or did I miss 
anything?


On 9/27/2009 1:46 PM, P T Withington wrote:
> These are shortcuts that old Lisp hackers know by heart 
> (http://bit.ly/2Ll3qS), although they have been renamed to be legal 
> Javascript symbols.  This is why we have not felt any need to document 
> them.  :)
> 
> They are supposed to work in all runtimes.  In an attempt to reduce 
> global namespace pollution, I moved them out of the global namespace 
> into `Debug.environment` (which is where they more properly belong -- 
> the Debugger should not be storing its state in the application's 
> namespace), as is stated in your first reference.  See the note at  line 
> 91 of swf9/LzDebug.as.  What really needs to happen is for the swf9 
> debug evaluator to wrap `with (Debug.environment) { ... }` around the 
> expressions it compiles, just as dhtml/LzDebug.js does in `doEval`.  I 
> think this has to happen in the compiler, not the debugger, because of 
> the other code the compiler wraps around evaluations to heuristicate 
> whether it is an expression or statement and to report errors.
> 
> On 2009-09-27, at 07:06, André Bargull wrote:
> 
>> The last three results of debugger evals are stored in '_', '__' and 
>> '___' to provide a fast way to access these values again. Currently, 
>> swf8 stores the values in the global object, whereas AS3 runtimes 
>> store the values in the global object "global". This means in swf8 you 
>> could write 'Debug.write("last result was %#w", _)', but this is 
>> currently not possible in swf9/swf10. My question: Should this be 
>> considered as a bug? I don't think there is any official documentation 
>> for these short-hands [1], so maybe it was only intended that '_' as a 
>> single expression should work?!
>>
>> PS: '_' as a single expression works in swf9/swf10, because that's a 
>> "simple expression" and therefore handled by "evalSimpleExpr" which 
>> calls "globalValue" and "globalValue" looks up values in the global 
>> object "global".
>>
>> [1] Google only found these two results:
>> - http://www.openlaszlo.org/pipermail/laszlo-dev/2009-June/021356.html
>> - http://jira.openlaszlo.org/jira/browse/LPP-630
> 
>