Visual D Debugger "complaints" (Mago?)

[Rainer Schuetze via Digitalmars-d-ide]

On 18.06.2016 17:57, Joerg Joergonson wrote:
> On Friday, 17 June 2016 at 08:18:59 UTC, Rainer Schuetze wrote:
>>
>> Visualizer code in the binary sounds like an interesting idea. Given
>> some convention on naming so that symbols are discoverable and rather
>> safe to call, that could be doable.
>>
>> Mago does not yet support calling code in the debugged process, so
>> that would be a first step to implement such kind of visualizers.
>
> It would be interesting, easy on the end user, and "portable" if it
> could be done.  Having it stored in modules could allow mago/VD to
> compile the code(since we know we have the compiler) outside the
> project. Generic debugging helpers could be written and shared. It just
> depends on the difficulty of implementing properly ;)

Visualizers in a separate module or even binary have the problem of not 
being able to access private symbols. Having it in a DLL built and 
loaded by mago/vd needs an extensive API for reflection and memory 
access. This seems like a larger project...

I'd rather start with some functions in the debuggee itself to be 
searched for the type data to be displayed, e.g.

string mago_visualizer(ref T data);
string mago_visualizer(T)(ref T data);

or some sink-delegate-version to avoid allocations.

mago will try to resolve these for T and its base classes. If it finds 
one, it is called and the string result is displayed.