Path: utzoo!attcan!uunet!slxsys!jclark!jjc
From: jjc@jclark.UUCP (James Clark)
Newsgroups: comp.text
Subject: Re: tbl error message:line 202: Too many text block diversions
Message-ID: <JJC.89Jul1101714@jclark.UUCP>
Date: 1 Jul 89 09:17:14 GMT
References: <19811@cos.com> <809@dtscp1.UUCP>
Sender: news@jclark.UUCP
Organization: None
Lines: 31
In-reply-to: scott@dtscp1.UUCP's message of 29 Jun 89 04:52:17 GMT

In article <809@dtscp1.UUCP> scott@dtscp1.UUCP (Scott Barman) writes:

   One of the problems is they all share the same namespace.  Therefore if you
   have a diversion named ZZ you cannot have a macro named ZZ as well.  This
   makes sense considering how diversions are used, but you cannot define a
   string as ZZ without doing strange things to troff!

   NOTE: Yes, I realize this is an argument for long names, but it is also one
   for a separate namespaces.

Separate name spaces for diversions, strings and macros are not a good
idea. It is an important feature of troff that diversions, strings and
macros not only share the same name space but are the same thing: for
example, you can use `as' or `am' on something defined with `di', or
you can interpolate with `\*' something defined with `di' or `de' For
a good example of how this can be useful have a look at how the man TP
macro works. It relies on the fact that you can do something like
this:

.di x
Label
.br
.di
.ds y \*x\
\*y Paragraph starts here on the same line as the label.

It is this sort of thing that makes implementing a troff that is input
compatible with the original not as easy as you might think.

James Clark
jjc@jclark.uucp