Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ncar!ico!rcd
From: rcd@ico.isc.com (Dick Dunn)
Newsgroups: comp.text
Subject: Re: In troff, is "|" supposed to be slanted in Italic?
Summary: no-win?
Message-ID: <1991May8.170359.8133@ico.isc.com>
Date: 8 May 91 17:03:59 GMT
References: <1470@ecicrl.ocunix.on.ca>
Organization: Interactive Systems Corporation, Boulder, CO
Lines: 40

clewis@ferret.ocunix.on.ca (Chris Lewis) writes:
[eqn example with | ]

> By my reckoning, the "pile" of "|" is in font 2 (Italic).  Psroff agrees...
...
> ...On the other hand, pscat seems to
> emit vertical "|" in this example.  I'm not sure whether pscat thinks
> it's in font 1 or 2, or whether this is special cased.

If by "pscat" you mean the TranScript one (just to be sure), this was the
subject of a bug fix some time ago; yes, it's a special case.  I would say
the situation is confused, at best:
	- TranScript (pscat and psdit) used to let the | character come
	  through in the current font.  This gave slanted bars if you were
	  in italic.
	- After the "fix" (change), the vertical bar was effectively
	  removed from regular fonts so that it would be picked up from
	  the Symbol font.  This gives upright bars throughout, but...
	- Now a constant-width font gets a bar of the wrong width!  The
	  bar from Symbol is too narrow, and cruftroff input that counts
	  on lining up constant-width text fails.

> I can fix this in psroff simply enough (have *all* "|" come out
> in Times-Roman), but this doesn't seem quite right to me.

This will give you the constant-width problem I mention.  But that can be
solved also.

Seems to me the problem is in the interpretation of the "bar" character.
I don't believe the character produced as a result of the ASCII | (0174,
0x7c) should ever be slanted.  The name of the ASCII character is "verti-
cal line", and it just doesn't seem like "vertical" should mean "possibly
slanted"!  If I had to assign blame, I'd assign it to the PostScript fonts
which encode a slanted character into that position...but that doesn't do
any good, 'cause it's done.  What little I can find on troff font examples
shows the vertical bar as vertical even in an italic font...so I'd fix it
to make 0x7c always produce a true vertical line of appropriate width.
-- 
Dick Dunn     rcd@ico.isc.com -or- ico!rcd       Boulder, CO   (303)449-2870
   ...If you plant ice, you're gonna harvest wind.