Move punctuation for cite commands other than autocite

[moewew]

This came up over at moewew/biblatex-ext#1 and made me wonder.

I always thought, only \autocite had the ability to move around punctuation marks. The feature can be enabled if the option autopunct is set to true by using the optional position argument for \DeclareAutoCiteCommand.

As it turns out, however, \textcite as defined by the verbose styles also moves punctuation around. I could not find any official word about this in the documentation. Unlike \autocite the feature can not be disabled easily with just one or two lines of code here, it is necessary to redefine \textcite in its entirety (about 20 lines of code). While I can definitely see that moving the punctuation mark is a nice feature, it strikes me as a bit unfortunate that the modifications necessary to disable that behaviour are so awkward and not particularly user friendly.

On the other hand it has always struck me as odd that there was no simple way to let other citation commands (in particular \footcite, \footfullcite, ...) move around punctuation marks.

So I was wondering whether or not it would be a good idea to enable moving of punctuation marks for all citation commands and offer a simpler interface to enable or disable that feature.
The code changes necessary to allow for the moving don't seem particularly challenging, although a few things should be sorted out and thorough testing would be needed. At the moment I believe the exact implementation of a useful interface would be more challenging.

I'd be interested in everybody's thoughts about the merit of this proposal as well as any input about issues that could arise with this and ideas for implementations.

[moewew]

A first attempt with a few drawbacks is at dev...moewew:citepunctmove.

The nature of the many nested commands that make up one citation commands made it hard to implement a more direct approach. \DeclareCitePunctuationPosition essentially redefines one of the internal cite constituents. This means that it must be issued after \DeclareCiteCommand and that we had to remember the wrapper command from an earlier \DeclareCiteCommand. Not very elegant, but it seems to work.

[moewew]

A more sophisticated attempt is at dev...moewew:cpm2. Comments are appreciated. I will prepare a pull request tomorrow.

Usage example

\documentclass[british]{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{babel}
\usepackage{csquotes}

\usepackage[style=authoryear, backend=biber, autocite=footnote]{biblatex}

\addbibresource{biblatex-examples.bib}

\DeclareCitePunctuationPosition{\footcite}{f}

\begin{document}
Lorem \autocite{sigfridsson}.

Ipsum \footcite{sigfridsson}.

Dolor\footnote{Sit \footcite{sigfridsson}.}.
\end{document}