Message-Id: <9302031437.AA22208@sc.zib-berlin.dbp.de>
Reply-To: Mailing list for the LaTeX3 project <LATEX-L@vm.urz.Uni-Heidelberg.de>
In-Reply-To:  POPPE@SWOV.NL Wed, 3 Feb 93 09:58:00 +0100
Date:         Wed, 3 Feb 93 09:36:52 EDT
From: Charles Wells <cfw2@PO.CWRU.EDU>
Sender: Mailing list for the LaTeX3 project <LATEX-L@vm.urz.Uni-Heidelberg.de>
To: Multiple Recipients of <LATEX-L@vm.urz.Uni-Heidelberg.de>
Subject:      Re: document classes & numbering systems
Status: R


This is a reply to Frank Poppe's.

> Each time I make an enumerated list I have two problems:
> - English not being my native language, I have to think twice where to put an
> "e" and where to put an "a" in "enumerate" - but that's not the subject :-)

You think native English speakers don't have such problems?

> - when I make a reference in the following paragraph(s) to "item~2" or
> "item~b" I realize that is is illogical to have LaTeX make the labels, and
> then hardcode them myself. But then I see how tedious it is to make and use a
> reference and leave it.
>
> Wouldn't it be possible to define an \item command with an (optional)
> parameters that give a pointer to the item-reference? Each
> enumerate-environment should use the same bits of memory otherwise TeX would
> run out of memory very soon. That means that the references are valid until
> the next enumerate. Only when it has to be valid after that, one should have
> to use the "old" system.
>
> Example:
> bla bla \begin{enumerate}
> \item[subjx] an x item
> \item[subjz] a z item\end{enumerate}
> The description of item~\ref{subjz} is....
>
> which should give "The description of item 2 is" or "...item ii is", depending
> on the document style.

I believe by your reference to the old system that you
understand that this could be done this way:

bla bla \begin{enumerate}
\item\label{subjx} an x item
\item\label{subjz} a z item\end{enumerate}
The description of item~\ref{subjz} is....

In my writing, the references to enumerated items are not a very
big percentage of all the references, and I believe this is true
of most mathematical writing.  So I think having a special
mechanism to reuse memory from one enumerate to the next would
not be helpful.  Is there any style of writing where most of the
references are to items in an enumeration?

I frequently use labeled lists so that I can refer to items in a
list anywhere in a large document.  Here is the code:

\newenvironment{labeledlist}[1]
{\begin{list}{{\rm#1.\arabic{lister}}}{\usecounter{lister}
\settowidth{\labelwidth}{#1.9}
\leftmargin\labelwidth \advance\leftmargin by \labelsep
}}%begin text
{\end{list}}

You start such a list by \begin{labeledlist}{BR} (for example)
and then the items are numbered BR.1, BR.2, and so on.  You
refer to an item as~BR.\ref{labelname} for that list, which
means in a big document you have a clue in the source file of
what you are referring to.

Michael Barr and I used labeledlist in a book we wrote, and I no
longer remember who wrote the code.


--
Charles Wells
Department of Mathematics, Case Western Reserve University
University Circle, Cleveland, OH 44106-7058, USA
216 368 2893