Re: Problems with Enhanced mode and Postscript

[Ethan A M. <merritt@u.washington.edu>]

On Sunday 06 July 2008, Philipp K. Janert wrote:
> 
> I see. Thanks. 
> 
> This does not just affect {}, though, but seems
> to be a problem with the escape-mechanism.
> 
> Stuff, like \~etc also does not work as expected.

Please read the comments beginning at line 2628 in the
file term.c.   The intent was to allow escapes of the
formatting characters used by the enhanced text mode:

     if (strchr("^_@&~",p[1]) == NULL)

Unfortunately at the time we overlooked the curly brackets,
which are not strictly speaking format characters but are
interpreted as a special case by the enhanced text code.
But as you see the '~' character is correctly handled
(confirmed here using both 4.2 and current CVS).
 
> Has this been introduced relatively recently? E.g.
> as consequence of including support for multibyte
> char sets?

Nope.  The current code has been this way since 2004.
(version 3.8 something).

	Ethan


> 
> Best,
> 
> 		Ph.
> 
> On Sunday 06 July 2008 17:29, you wrote:
> > On Sunday 06 July 2008, Philipp K. Janert wrote:
> > > There seem to be some inconsistencies regarding
> > > the behaviour of "escape" characters when using
> > > enhanced text mode with Postscript terminals.
> > >
> > > According to the documentation, backslashes
> > > escape control characters. Furthermore, single
> > > backslashes should be used with single-quoted
> > > strings, but double backslashes with double-quoted
> > > strings.
> > >
> > > Here are the commands:
> > > 	set label 1 at 0,0 "f\\{x\\}"
> > > 	set label 2 at 0,1 'f\{x\}'
> > > 	plot [-1:1][-1:2] 3
> >
> > This is a known bug.
> > # 1968636  	  incorrect treatment of '\{' and '\}' in postscript
> >
> > It would be easy to fix, except that it may have bad side effects for
> > multibyte encodings, in particular SJIS and EUC.  Shige Takeno was
> > kind enough to investigate the earlier escape sequences.
> > Perhaps he could do the same for this pair as well.
> >
> > 	Ethan
> >
> > > This should create two labels, looking like:
> > > 	f{x}
> > >
> > > Everything looks good (as expected) using
> > > wxt enhanced.
> > >
> > > But when using Postscript, I find output that
> > > looks like this:
> > > 	f\x\
> > > for both labels.
> > >
> > > Is this a known issue?
> > >
> > > Best,
> > >
> > > 		Ph.
> 
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-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742