[x3d-public] Finding more than one use of a DEF in VRML - Chisel, duplicated DEF in proto

[Don Brutzman]

On 3/26/2020 8:54 AM, John Carlson wrote:
> As mentioned on other thread:
> 
> https://www.web3d.org/x3d/content/X3dTooltips.html#ID
> 
> "*ID <https://www.w3.org/TR/REC-xml/#sec-attribute-types>* is a NMTOKEN that is unique within the scene, corresponding to the DEF attribute in X3D. "
> 
> This would mean that the DEF attribute is unique within a scene?  Or no?
> 
> Help!   The sky is falling!
> 
> John

that is exactly why you want to read my note from earlier today, conveniently appearing below in your message:

"Wondering if we should define a suggested practice for de-duplicating DEF names within a proto"

> On Thu, Mar 26, 2020 at 9:26 AM Don Brutzman <brutzman at nps.edu <mailto:brutzman at nps.edu>> wrote:
> 
>     On 3/25/2020 7:11 PM, GPU Group wrote:
>      > Chisel? "it was simply put in the public domain by Trapezium when they folded many years ago. They didn¹t specify any license" - Louka
>      > http://dug9.users.sourceforge.net/web3d/temp/chisel-src.zip
> 
>     Also
> 
>     * X3D Resources: Conversions and Translation Tools
>     https://www.web3d.org/x3d/content/examples/X3dResources.html#Conversions
> 
>     * 15. Chisel VRML Optimisation Tool
>     http://www2.hrp.no/vr/tools/chisel/install.htm
> 
>         with autoinstaller
>     http://www2.hrp.no/vr/tools/chisel/install.htm
> 
>         and documentation
>     http://www2.hrp.no/vr/tools/chisel/doc/index.html
> 
>         provided by Halden Virtual Reality Centre.
>     http://www2.hrp.no/vr/about/index.html
> 
>         Originally built by Trapezium and maintained by NIST.
>     http://ovrt.nist.gov/chisel.html
>         (link no longer working, hoping to find replacement)
> 
>      > But I suspect double-deffing isn't illegal. I think I've been through it, and different browsers honored the first or last definition.
>      > -Doug
> 
>     Agreed.  Although it is legal in X3D abstract specification and in VRML/ClassicVRML encodings, it leads to validation difficulties in XML (and at some point JSON when JSON Schema is finished).
> 
>     Wondering if we should define a suggested practice for de-duplicating DEF names within a proto, e.g.
> 
>              MyWhizzyProto includes DEF SomeDuplicatedName
> 
>     might get tidied up to globally rename
> 
>              MyWhizzyProto includes DEF MyWhizzyProto.SomeDuplicatedName
> 
>     We might also apply this in the PrototypeExpander work if that gets revisited.
> 
>     Thoughts?
> 
>      > On Wed, Mar 25, 2020 at 7:43 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> <mailto:yottzumm at gmail.com <mailto:yottzumm at gmail.com>>> wrote:
>      >
>      >     That is, more than one DEF with the same value.
>      >
>      >     I realize that separate PROTOs may have the same DEF due to namespaces. Unfortunately writing a Unix script to find this takes massive brain power.
>      >
>      >     John
>      >
>      >     On Wed, Mar 25, 2020 at 8:37 PM John Carlson <yottzumm at gmail.com <mailto:yottzumm at gmail.com> <mailto:yottzumm at gmail.com <mailto:yottzumm at gmail.com>>> wrote:
>      >
>      >         I’m not particular looking for a vrml parser unless it catches double use of a DEF.
> 
>     all the best, Don
>     -- 
>     Don Brutzman  Naval Postgraduate School, Code USW/Br brutzman at nps.edu <mailto:brutzman at nps.edu>
>     Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
>     X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman
> 

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman