this time I have an MHEG-5 related problem with the format of the
GroupIdentifier defined in the DAVIC 1.3, part 9 specification.
I think that that the specification for one of the shorthand notations
is wrong. Let me show you why:
The following is an EBNF of the definition of the GroupIdentifier:
GroupIdentifier ::= CompleteGroupIdentifier | Shorthand1 | Shorthand2 .
CompleteGroupIdentifier ::= [Source] PathOrigin [Path] Filename .
Source ::= <STRING>":" .
PathOrigin ::= "//" | "/" .
Path ::= Directory+ .
Directory ::= <STRING>"/" .
Filename ::= <STRING> .
Shorthand1 ::= "~/" [Path] Filename .
Shorthand2 ::= "/" [Path] Filename .
A valid CompleteGroupIdentifier would be, for example, "/abc/scene.mheg",
right?
The Source is an optional component. "/" is an indication that the following
part is to be treated as a relative path starting from the directory that
contains the Application object. "abc/" is a sub-directory of that directory.
"scene.mheg" is the filename of the requested object. So, if the Application
object has the GroupIdentifier "DSM://myApp/startup" the actual fully
qualified identifier for the Scene object is "DSM://myApp/abc/scene.mheg".
Right?
Using the first shorthand method the GroupIdentifier would be
"~/abc/scene.mheg". Using the second shorthand method the GroupIdentifier
would be "/myApp/abc/scene.mheg". Right?
The problem is, how can the second shorthand notation be distinguised from
a GroupIdentifier with no Source component and the PathOrigin of "/" ?
Any expert opinion?
Thanks in advance and best regards,
Andreas
-- o _ Andreas Kraft (\_|_) GMD FOKUS, kraft@fokus.gmd.de, +49 30 3463-7232 T> ] [ The sky is the limit