[squeak-dev] Re: Pragmas (Re: The Inbox: Morphic-phite.429.mcz)

Hannes Hirzel hannes.hirzel at gmail.com
Mon Apr 26 23:19:58 UTC 2010

On 4/26/10, Andreas Raab <andreas.raab at gmx.de> wrote:
> On 4/26/2010 3:47 PM, Hannes Hirzel wrote:
>> And: to me the code for the menu definitions looks ugly. A kind of
>> assembler like, lisp-s expression thing with a lot of implied
>> assumptions.
> I think you're missing the point of why one would use an annotation.
> They're there for discovery by other code. You are basically announcing
> "hey if anyone cares, here's an action that you might want to place in a
> menu".
> MenuSpec doesn't achieve that. Yes, you got a menu spec, but now what?
> You also need a registry, let's say TheWorldMenu. Then you add another
> registry for TheMainDockingBar. Then we refactor this and introduce new
> classes, say the TheMainMenu and TheContextMenu. Now you've got to deal
> with four different situations. This all goes away by using annotations.
> If there's code that knows how to discover these specs, it will do so.
> If not, it just leaves the code alone.
> Most importantly a third party trying to extend the main menu doesn't
> need to update their code because the implementation in the base system
> changes.
>> The MenuSpec is a straighforward thing. And I think it is more
>> appealing for the younger generation.
> I fail to see what age has to do with this discussion. However, if you
> look at the "current" crowd of programming languages they pretty much
> all have annotations, from C# to Python, which are used for very similar
> purposes.
>> The practical problem we are currently facing with Squeak 4.1 is that
>> it cannot display pictures in the the file browser and that adding
>> entries to the menu is not possible in a clean way.
> Correct, but I see this as a an example of a discussion on how we
> achieve a more decoupled system. For the purpose at hand, where we'd
> like 3rd parties to use and extend the base system while allowing the
> base system itself to evolve, I find the annotation-based discovery
> superior to hardcoded references to classes and registries that may not
> exist in this form in the future.
> Cheers,
>    - Andreas
Thank you Andreas for this valuable in-depth explanation. It is
convincing for me.


More information about the Squeak-dev mailing list