code for #1632

base/changes.txt

@@ -6,6 +6,12 @@ to completeness or accuracy and it contains some references to files that are
 not part of the distribution.
 ================================================================================
 
+2025-01-22  David Carlisle  <[email protected]>
+
+	* ltcounts.dtx, ltxref.dtx:
+	Allow * to denote the current counter (as used by \label) in counter
+	related commands, \alph*,  \stepcounter*, etc. (gh/1632)
+
 2025-01-21  Joseph Wright  <[email protected]>
 
 	* ltcmd.dtx:

base/doc/ltnews41.tex

@@ -244,6 +244,14 @@ \subsection{Socket and plug conditionals}
 %
 \githubissue{1577}
 
+\subsection{Accessing the current counter}
+Counter commands such as \cs{alph}, \cs{stepcounter}, may now have
+the argument \texttt{*} to denote the current counter (as used by
+\cs{label}).  This is compatible with the package \pkg{enumitem} use of
+\verb|\alph*| in item labels but is generally available.
+%
+\githubissue{1632}
+
 \section{Code improvements}
 
 \subsection{Refinement of \cs{MakeTitlecase}}

base/ltcounts.dtx

@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltcounts.dtx}
-             [2024/10/26 v1.1p LaTeX Kernel (Counters)]
+             [2025/01/22 v1.2a LaTeX Kernel (Counters)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltcounts.dtx}
@@ -56,14 +56,17 @@
 %</driver>
 % \fi
 %
+% \providecommand\env[1]{\texttt{#1}}
 %
 % \changes{v1.0c}{1994/03/29}
 %     {Create file from parts of ltmiscen and ltherest.}
 % \changes{v1.1a}{1994/05/19}{Extracted file from ltcntlen.}
 % \changes{v1.1d}{1996/04/23}{Documentation improvements}
 %
 % \section{Counters and Lengths}
-% Commands for defining and using counters. This file defines:
+% Commands for defining and using counters.
+% This file defines the following commands. In each case \marg{counter} may be
+% |*| denoting the current counter as set by a previous |\refstepcounter|.
 %
 % \DescribeMacro{\newcounter}
 % To define a new counter.
@@ -72,13 +75,13 @@
 % To set the value of counters.
 %
 % \DescribeMacro{\addtocounter}
-% Increase the counter |#1| by the number |#2|.
+% Increase the \marg{counter} |#1| by the number |#2|.
 %
 % \DescribeMacro{\stepcounter}
-% Increase a counter by one.
+% Increase the \marg{counter} by one.
 %
 % \DescribeMacro{\refstepcounter}
-% Increase a counter by one, also setting the value used by |\label|.
+% Increase the \marg{counter} by one, also setting the value used by |\label|.
 %
 %
 % \DescribeMacro{\value}
@@ -246,7 +249,19 @@
 %    \end{macrocode}
 % \end{macro}
 %
-% \begin{macro}{\@newctr}
+% \begin{macro}{\c@*}
+% \changes{v1.2a}{2025/01/22}{\cs{c@*} added (gh/1632)}
+% Make the current counter available as a \LaTeX\ counter
+% with name |*|, so |\alph*| returns the current
+% counter as a letter, |\stepcounter{*}| increments the current
+% counter, etc.
+%    \begin{macrocode}
+\protected\expandafter
+  \def\csname c@*\endcsname{\value\@currentcounter}
+%    \end{macrocode}
+% \end{macro}
+
+%\begin{macro}{\@newctr}
 % \changes{v1.0d}{1994/04/09}
 %     {\cs{@nocnterr} now has counter name argument}
 % \changes{v1.0e}{1994/04/17}

base/ltxref.dtx

@@ -33,7 +33,7 @@
 %<*driver>
 % \fi
 \ProvidesFile{ltxref.dtx}
-             [2024/12/10 v1.1s LaTeX Kernel (Cross Referencing)]
+             [2025/01/22 v1.1t LaTeX Kernel (Cross Referencing)]
 % \iffalse
 \documentclass{ltxdoc}
 \GetFileInfo{ltxref.dtx}
@@ -424,6 +424,7 @@
 %  \changes{v1.1r}{2024/09/20}{set also \@currentHref}
 %  \changes{v1.1r}{2024/09/20}{provide a kernel copy \@kernel@refstepcounter}
 %  \changes{v1.1r}{2024/09/20}{add sockets}
+%  \changes{v1.1t}{2025/01/22}{Guard * from causing infinite loop}
 %    \begin{macrocode}
 %<latexrelease>\IncludeInRelease{2022/06/01}%
 %<latexrelease>                 {\Ref}{Add starred version}%
@@ -462,10 +463,14 @@
 %    \end{macrocode}
 % \end{plugdecl}
 %    \begin{macrocode}
+\def\ltx@star@counter{*}
 \def\refstepcounter#1{%
   \UseSocket{refstepcounter}{%
     \stepcounter{#1}%
-    \edef\@currentcounter{#1}%
+    \edef\reserved@a{#1}%
+    \ifx\reserved@a\ltx@star@counter\else
+      \let\@currentcounter\reserved@a
+    \fi
     \protected@edef\@currentlabel
 %    \end{macrocode}
 %    By generating the second csname first the |\p@...| command can
@@ -501,7 +506,10 @@
 \def\@kernel@refstepcounter#1{%
   \UseSocket{refstepcounter}{%
     \stepcounter{#1}%
-    \edef\@currentcounter{#1}%
+    \edef\reserved@a{#1}%
+    \ifx\reserved@a\ltx@star@counter\else
+      \let\@currentcounter\reserved@a
+    \fi
     \protected@edef\@currentlabel
        {\csname p@#1\expandafter\endcsname\csname the#1\endcsname}}}%
 %    \end{macrocode}