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 Sender: Mailing list for the LaTeX3 project <[log in to unmask]> Date: Fri, 21 Apr 2017 17:35:09 +0200 Reply-To: Mailing list for the LaTeX3 project <[log in to unmask]> Message-ID: <[log in to unmask]> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In-Reply-To: <[log in to unmask]> Content-Type: text/plain; charset=utf-8; format=flowed From: Frank Mittelbach <[log in to unmask]> Parts/Attachments: text/plain (47 lines) Am 21.04.2017 um 16:49 schrieb Benedikt Vitecek: > For a command I used the argument specifier d<> (which I thought was a > good idea), > which doesn’t work properly in combination with ‚babel‘ and the language > option > ‚spanish‘: > > \documentclass[spanish]{scrartcl} > \usepackage{babel} > \usepackage{xparse} > \NewDocumentCommand \Something { d<> m } > { > Optional: #1 \\ > Mandatory: #2 > } > \begin{document} > \Something{World} > \end{document} the problem is that babel only enables < as an active character after begin document, i.e., when you make that definition in the preamble "<" is still a normal character (\catcode 12 presumably, not checked). After \begin{document} it is an active char and therefore the xparse scanning no longer matches. If you move the definition there your document works as expected. In my opinion there is nothing xparse or expl could do here, it needs a different shorthand interface in babel --- it might be that there is something there to enable shortcuts already in the preamble This is a tricky area as babel hides the fact for a reason: there are probably a good number of packages that would fall over if the mechanism is exposed while they are setting up their internals. Basically, this is an issue with legacy code that is difficult to resolve in a perfect way as long as those interfaces aren't universally available but are added by packages. This is all a bit of hand-waving as I haven't looked at the babel internals for a while; so perhaps Javier or somebody else can give a more accurate answer. frank