Message-Id: <199402081702.AA21011@mail.cs.tu-berlin.de>
Reply-To: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
Date:         Tue, 8 Feb 1994 18:01:36 +0100
From: "J%org Knappen, Mainz" <KNAPPEN@VKPMZD.KPH.UNI-MAINZ.DE>
Sender: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
To: Multiple recipients of list LATEX-L <LATEX-L@DHDURZ1.BITNET>
Subject:      Re: additional features
Status: R

Third type of braces:

The most convenient choices will be the round ones, like in
\cmd[opt1](opt2){required}
LaTeX allready uses round braces in the \put. However, round braces become
involved, if the optional argument may contain itself a round brace -- you
have to check for round brace balance and all that.

The next choice would be angular ones, as in
\cmd[opt1]<opt2>{required}
but those immediately break with e.g. french.sty where the angualar braces
are made active.

This argument also applies to the choise of vertical bars, like in
\cmd[opt1]|opt2|{required}
where as slashes are ruled out by the possibility of occuring in the
argument itself.

The conclusion is, that there are no special characters left, which can be
employed for that purpose with resonable effort and without breaking
anything else. The LaTeX2e solution,
\cmd[opt1]{required}[opt2]
is really ingenious.

Yours, J"org Knappen.

Wait a minute -- the star is maybe available for commands which have no
star form, (this rules out \section again) as in
\cmd[opt1]*opt2*{required}
allthough stars could also occur in the optional argument...