RE: editing -- oops, correction

["Cruikshank, David W" <David.Cruikshank@PSS.Boeing.com>]

These two items (proposal for 3.1.2.1 and EBNF option) are the last things holding up the final production of the Release 2 WebCGM profile....Please comment and come to a decision.

thx...Dave

> ----------
> From: 	Lofton Henderson[SMTP:lofton@rockynet.com]
> Sent: 	Tuesday, April 10, 2001 10:59 AM
> To: 	Dieter; Cruikshank, David W
> Cc: 	cgmopen-members@lists.oasis-open.org
> Subject: 	Re: editing -- oops, correction
> 
> At 06:38 PM 4/10/01 +0200, Dieter Weidenbrueck wrote:
> >[...]
> >I am not sure whether this change would be correct.
> >
> >pictseqno is a keyword, whereas picseqno is just a placeholder for a
> >character between '0' and '9'. It would have been less confusing to choose a
> >different expression for this, but I think it is correct.
> >
> >[...]
> >
> >----- Original Message -----
> >From: "Cruikshank, David W" <David.Cruikshank@PSS.Boeing.com>
> >[...]
> > > ok, so I think the editing directive is to change the 2 occurrances of
> >picseqno in 3.1.2.1 to pictseqno...I'll go ahead and do that.
> 
> I think the change is correct, but the wording of the sections is poor (who 
> wrote this stuff?!):
> 
> The title of the section is:  "3.1.2.1  Picture Selection 
> Keywords".  Clearly, in 1st paragraph 'pictid' is the keyword.  The 
> paragraph talks about its value, which is the "id" of the picture.  To be 
> consistent, the 2nd pgph should start with the keyword, 'pictseqno'.
> 
> Okay, in theory we could change the 1st paragraph, change the section 
> title, etc.  But I think it is bad practice to be talking in the text about 
> intermediate, non-terminal productions in the BNF -- the "placeholder" as 
> you call it.
> 
> So let's reword to remove all ambiguity:
> 
> ### begin ###
> pictid - The pictid [Ed: use same font as 1st word] keyword indicates that 
> selection of the picture to be viewed is by the id of the picture, which is 
> the id parameter in the BEGIN PICTURE element. The picture id value is the 
> first, required parameter associated with the keyword (see EBNF), and there 
> may be a second associated parameter, which is an optional picture behavior 
> specification.  If the metafile does not contain a picture with the 
> specified picture id value, the first picture in the metafile is chosen.
> 
> pictseqno - The pictseqno [Ed: use same font as 1st word] keyword indicates 
> that selection of the picture to be viewed is by the sequence number of the 
> picture in the metafile. "1" is the first picture, "2" is the second 
> picture, etc. The picture sequence number value is the first, required 
> parameter associated with the keyword (see EBNF), and there may be a second 
> associated parameter, whose value is an optional picture behavior 
> specification.  If the specified picture sequence number value exceeds the 
> number of pictures in the metafile, the last picture is displayed.
> ### end ###
> 
> Now, the use of "1" (instead of 1) made me look back to the EBNF.  We 
> already have a bug fix to the [0-9]+, to prevent the value 0 (ZERO).  So 
> how about this:
> 
> picseqno ::= (non-zero-digit)(digit)*
> [...]
> non-zero-digit ::= "1" | ... | "9"
> digit ::= "0" | digit
> 
> Of course, this prevents you from writing picture sequence numbers with 
> leading zeros, "001".  Does anyone care?  If someone objects to this 
> change, then we can leave it as (digit)+ (which is better, I think, than 
> [0-9]+), and add to the 3.1.2.1, before the "exceeds number of pictures" 
> sentence, "The specified picture sequence number value shall be positive."
> 
> Please comment:  option 1 (enforce positive via EBNF change, which has the 
> "no leading" ); or, option 2 (enforce positive via words in 3.1.2.1).
> 
> Or option 3:  (digit)*(non-zero-digit)(digit)*   (BNF expression for 
> positive, leading zeros allowed!).
> 
> All,
> -Lofton.
>