Re: Using/requiring Cairo

[karl]

David Kastrup:
> address@hidden writes:
> 
> > Han-Wen Nienhuys:
> >> On Sat, Jun 24, 2017 at 12:43 PM, David Kastrup <address@hidden> wrote:
...
> > If no one else like to care for postscript, I can step in to handle it.
> 
> I don't know what that means.

It's like english, I am willing to take care of something related to
the programming language PostScript, so we don't need to convert to
cairo.

>  My proposed migration plan would not have
> changed the PostScript backend at first, but it certainly would have
> been slated for eventual retirement.

And I more or less said that I didn't like the retirement thing.
If you already decided to switch to cairo, then fine, tell us so 
we can stop this discussion.

> >> > We might also be able to forego creating PostScript as an
> >> > intermediate stage to creating PDF and create bitmap formats
> >> > without using PostScript as well (again, this should really speed
> >> > up things).
> >
> > I use PS as the final format.  Cairo can export to postscript but it's
> > PS is not nice to read, lilypond PS is much better in that respect.
> 
> PostScript is not intended to be human-readable rather than
> human-writable and streamable,

PostScript is a programming language suited for printing and other 
things. Why youldn't I like to have that readable and understandable 
like any other code ?

> two characteristics PDF no longer cares
> about in return for better computer-readability and processability.

PDFReference16.pdf is 1236 pages long and is no easy read.

The first version of the green/blue/red book was good at getting you 
started at postscript, do you have any similar doc to get you started
at pdf ?

Yes, they say that pdf it is for better computer-readability and
processability, but it isn't a stable interface, things are being
added which breaks some viewers, and fonts are still missing in
some cases, which was a point going from ps to pdf. In contrast to
ps which has a stable interface/reference, PLRM3 is first printed
1999 and still in effect.

I have tried to find some free lib to use to read pdf's, if you know
of one please tell me, preferable for perl. Currently I'm using
"pdftohtml --xml", but there is a few things missing with that solution.

I know about poppler, citing:
  https://freedesktop.org/wiki/Software/poppler/
//
 Documentation

 There is currently very little documentation. 
//

Soo, the computer-readability is a nice goal, but not so much attained.

...
>  That makes it a lot less likely to be
> suitable for mechanical processing (like using "Tailor") than PostScript
> generated from a general-purpose representation with commonly used
> toolkits.
...

Ok, stop bullshitting. Both ps and pdf are a "general-purpose 
representaion", both have "commonly used toolkits", and both are 
suitable for "mechanical processing" (by e.g. a printer).

What is "Tailor" in this context, I don't understand what you mean by 
that ?

Regards,
/Karl Hammar

-----------------------------------------------------------------------
Aspö Data
Lilla Aspö 148
S-742 94 Östhammar
Sweden
+46 173 140 57