tagform applied unevenly

[juhaszp95]

Hi There,

I'm trying to make my equation tags use the capital form of the numbers/letters/symbols, which is especially important in the appendix where e.g. Eq. (A.1) would look 'uneven' otherwise. However, when I declare the relevant tagform, it only seems to apply to a part of the tag.

MWE (to be run in LuaLaTeX):

\documentclass{article}
\usepackage{libertinus-otf}
\usepackage{mathtools}

\begin{document}
	\newtagform{caps}[\addfontfeatures{Letters=Uppercase}]{(}{)}
	\usetagform{caps}

	%\let\oldeq\theequation
	%\renewcommand\theequation{\addfontfeatures{Letters=Uppercase}\oldeq}

	\begin{equation}
		bla
	\end{equation}	
\end{document}

This gives me:

Notice the different brackets. Basically, I'd like both the brackets and the letters/numbers in the tag itself to use \addfontfeatures{Letters=Uppercase}. The commented lines in the code let me apply it to the number itself, but not the brackets. Any help would be appreciated.

[muzimuzhi]

In current implementation, the optional argument of \newtagform{<name>}[<inner_format>]{<left>}{<right>}, inner_format, is inserted after <left> hence is expected to influence the equation number only, by taking it as argument.

mathtools/mathtools.dtx

Lines 3311 to 3313 in 58d1461

	\def\MT_define_tagform:nwnn #1[#2]#3#4{
	\@namedef{MT_tagform_#1:n}##1
	{\maketag@@@{#3\ignorespaces#2{##1}\unskip\@@italiccorr#4}}

mathtools/mathtools.dtx

Lines 3322 to 3332 in 58d1461

	\providecommand*\newtagform[1]{%
	\@ifundefined{MT_tagform_#1:n}
	{\@ifnextchar[%
	{\MT_define_tagform:nwnn #1}%
	{\MT_define_tagform:nwnn #1[]}%
	}{\PackageError{mathtools}
	{The~ tag~ form~ `#1'~ is~ already~ defined\MessageBreak
	You~ probably~ want~ to~ look~ up~ \@backslashchar renewtagform~
	instead}
	{I~ will~ just~ ignore~ your~ wish~ for~ now.}}
	}

As a workaround you can try prepending the format code to <left>, like \newtagform{brackets2}{\addfontfeatures{Letters=Uppercase}(}{)}

\documentclass{article}
\usepackage{libertinus-otf}
\usepackage{mathtools}

\begin{document}
	\newtagform{brackets2}[\addfontfeatures{Letters=Uppercase}]{(}{)}
	\usetagform{brackets2}

	\begin{equation}
		bla
	\end{equation}

	\renewtagform{brackets2}{\addfontfeatures{Letters=Uppercase}(}{)}

	\begin{equation}
		bla
	\end{equation}
\end{document}

[juhaszp95]

Perfect, this solves my problem, many thanks. I'll keep the issue open in case you want to change the implementation, but feel free to close it if you like.

[daleif]

@muzimuzhi wouldn't it be enough here to just use

 \def\MT_define_tagform:nwnn #1[#2]#3#4{ 
   \@namedef{MT_tagform_#1:n}##1 
     {\maketag@@@{#3\ignorespaces{#2{##1}}\unskip\@@italiccorr#4}} 

(and extra set of braces), not sure if is breaks something.

We cannot add #2 inside {##1} as one might want to access it as an argument.

[daleif]

Addd a brace pair such that anything in #2 only applies to {##1}