Message-Id: <199402111440.AA26470@mail.cs.tu-berlin.de>
Reply-To: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
Date:         Fri, 11 Feb 1994 15:39:00 +0100
From: Frank Poppe <POPPE@swov.nl>
Sender: Mailing list for the LaTeX3 project <LATEX-L@DHDURZ1.BITNET>
To: Multiple recipients of list LATEX-L <LATEX-L@DHDURZ1.BITNET>
Subject:      Re: On compatibility in LaTeX2e [was: Re: keyed options lis
Status: R

Rainer Schoepf <schoepf@SC.ZIB-BERLIN.DE>:

RS> Coming back to the proposal above for LaTeX3, namely using the syntax
RS>
RS> \command[[key1]value1[key2]value2]{required}
RS>
RS> this is a problem as you cannot have TeX grab everything between
RS> matching pairs of square brackets, only between [ and the next ].
RS> That leaves only the hand-crafted argument scanning mechanism, which
RS> might lead to a performance problem. This statement is very tentative,
RS> we haven't actually tried this, so I can't say that this is much
RS> slower.
RS>
RS> On the other hand, I find the syntax with the equal sign easier to
RS> understand. The only possible incompatibility is if an optional
RS> argument in the current system would contain an equal sign. However,
RS> that is very unlikely, as most optional arguments are either from a
RS> fixed set [thb], or of a fixed type (e.g., a length). \documentclass
RS> and \usepackage seem to be the only exception, plus any new command
RS> that a package might possibly define. This cannot be ruled out
RS> completely, but I think that package writers are not likely to invent
RS> options with equal signs in them.
RS>

I agree that the key=value syntax is easier to understand.
But remember that this line of discussion started with the wish to have
more optional commands on the \section command: the ability to specfify
different texts for t-o-c and mark's, apart from the section title to
appear in the text. The chance that somebody would want to use an equal
sign may not be great, but shouldn't be ignored either.

_____________________________________________________________________________
 Frank Poppe             <poppe@swov.nl>                tel:   +31 70 3209323
 Institute for Road Safety Research SWOV                fax:   +31 70 3201261
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