[Vm-dev] mantis http://bugs.squeak.org/view.php?id=7349

Andreas Raab andreas.raab at gmx.de
Thu May 7 15:38:38 UTC 2009

Igor Stasenko wrote:
>> It makes absolutely no sense to say "oh, we'll all just look it up and then
>> somehow it's going to magically work". Version information is *critical* if
>> you want to play things together in the long term - it has allowed us to
>> have a very smooth ride for a very long time in this area and I wish Squeak
>> would have more of that in general.
> Taking a function pointer by name, is nothing more than enumerating
> the VM capabilities.
> Take a look at OpenGL extension mechanism. Do they have to change the
> version of OpenGL each time they want to add new functionality? No.
> You can simply ask the library about support of certain capability -
> and depending on answer decide what to do.

Yes, OpenGL is a great example. Because what the OpenGL consortium does 
is moving extensions into core functionality, increasing the version 
number of OpenGL so that clients know they can rely on a documented and 
stable API. Exactly my point.

I have no problems with a named lookup mechanism in addition to a core 
interface. In fact we have one, it's ioLoadFunctionFrom. It solves a 
useful problem, namely that of how to support entry points where you 
don't know whether they will be available in the future or if it's only 
for use in this one version. But it's not a replacement for a documented 
core API.

   - Andreas

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