[x3d-public] scoping for proto names ?

[John Carlson]

Reread.   I think that def and name for in the same ProtoDeclare should be
aliased, or you should push twice on the scope stack.

On Sun, Jun 7, 2020 at 5:09 PM Andreas Plesch <andreasplesch at gmail.com>
wrote:

> Thanks. The question really if it is appropriate to ignore scoping for
> proto names. It looks like it is, -Andreas
>
> On Sun, Jun 7, 2020 at 4:50 PM John Carlson <yottzumm at gmail.com> wrote:
>
>> I learned some about scope by studying how LISP/Scheme implemented them.
>>   It’s like a stack of maps,  when you enter a new scope, you get a new
>> map, and push it on the stack,   When you exit a scope, you pop the map.
>> You can enter new fields into the map with their values.
>>
>> John
>>
>> On Sun, Jun 7, 2020 at 3:41 PM Andreas Plesch <andreasplesch at gmail.com>
>> wrote:
>>
>>> Let's see if I can explain this question clearly.
>>>
>>> First the example:
>>>
>>>
>>> https://github.com/andreasplesch/x3dom/blob/gh-pages/test/functional/proto/castle/proto_nested.x3d
>>>
>>>
>>> The table2 ProtoBody uses an instance of the leg2 proto. The leg2 proto
>>> declaration is defined outside of the table2 proto declaration name scope.
>>>
>>> The expected result is that the table2 proto declaration is able to use
>>> the name 'leg2' to find the leg2 proto definition.
>>>
>>> This does not work in my x3dom proto exploration and it took me a while
>>> to realize that the reason is (too?) strict scoping. The leg2 proto
>>> definition occurs outside of the execution context and name scope of the
>>> table2 proto. Therefore it is not visible to the table2 proto.
>>>
>>> At first glance this strictness seems not unreasonable, however, all
>>> tested browsers display the scene as expected.
>>>
>>> So I am somewhat puzzled. I think what it means is that name scoping
>>> does not apply to the name of Protos given by the name attribute, since the
>>> name of Proto is the name of a node definition. Proto names are possibly
>>> global.
>>>
>>> One consequence is that two Protos in a scene cannot have the same name.
>>> And I recall that this case is spec'ed to lead to undefined behaviour.
>>>
>>> Would it be correct to treat Proto names as global ? To be clear, by
>>> Proto name I refer to the name given by the name attribute, not a DEF name
>>> of an instance.
>>>
>>> Thanks for any insight, or pointers to relevant spec. sections, -Andreas
>>>
>>> --
>>> Andreas Plesch
>>> Waltham, MA 02453
>>> _______________________________________________
>>> x3d-public mailing list
>>> x3d-public at web3d.org
>>> http://web3d.org/mailman/listinfo/x3d-public_web3d.org
>>>
>>
>
> --
> Andreas Plesch
> Waltham, MA 02453
>
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