🚀 go-pugleaf

In article <9FDC95A6F0A6D680@UK.AC.CAM.PHX> CET1@phoenix.cambridge.ac.UK writes:
>I know one shouldn't look a gift horse in the mouth, but ... there seems
>to be considerable confusion about the version numbers in the recent
>batch (16 Jan) of Adobe standards available from their file server:
>
> The new struct.ps announces itself as Version 2.1, and the Examples
> at the end start "%!PS-Adobe-2.1". But in other places it talks as
> though the version number were still 2.0 (e.g. sections 4.3, 5, and
> 5.1 talks explicitly about using the string "%!PS-Adobe-2.0" to start
> the document).

Sigh.  This is all my fault.  The problem basically is that I am using
a fairly feature-less document processing system which does not allow
"linking" of pieces of text.  Subsequently I have to update all the
instances of a version number by hand.  Sometimes I get it right,
sometiems I don't.

RULE OF THUMB:  Trust the version number that is in the biggest point
size, and the one that is the closest to the front of the document :-)

> The new PPDformat.ps calls itself Version 3.0 initially. Then it has
> a `NOTE' which makes one think it might be 2.1. Then, to be ultimately

The NOTE indicates (though perhaps worded poorly) that all versions of
the document after and including 2.1 contain that update.

> confusing, it has an example PostScript document (on page 4) starting
> "%!PS-Adobe-3.0", as though there were a version 3.0 of the Document
> Structuring Conventions as well.
>
>Can anyone from Adobe (or anyone at all) say what the situation about
>version numbers really is?

Here are the proper version numbers for those documents:
    Structuring Conventions:	2.1
    Encapuslated PostScript	2.0
    Printer Description Files:	3.0

>Here is something else that might cause unseemly mirth. All the new
>documents have been prepared with a system that generates PostScript
>which has a spurious extra %%Page containing code that never generates
>anything. Thus when the %%Pages: comment claims that it is going to
>generate N pages, only N-1 are actually printed.

That's a different issue, but thanks for pointing it out.

Sorry if this has caused any confusion.  Version numbering and
compatibility is a tricky issue.  If you are writing a parser, you need
to know exactly what you can expect or not expect in a given version of
the file.  That is the most important reason for version numbers.
Their secondary value is to be sure you have the latest and greatest of
something.  Again, if you trust the version number on the title page of
the documents, you won't be led astray.  I'll fix the inconsistencies
pointed out in this message.

Thanks,
 Glenn Reid
 Adobe Systems
 Developer Tools & Strategies