From 988d1c5db5d01e9506672e0430a11b314bf6c525 Mon Sep 17 00:00:00 2001
From: Frank Fuhlbrück
Date: Fri, 11 Feb 2022 22:14:01 +0100
Subject: ver 0.11 - local references

---
 examples/exshexample.tex |  6 ++--
 exercisesheets.sty       | 73 +++++++++++++++++++++++++++++++-----------------
 exercisesheets.tex       | 54 +++++++++++++++++++++++++++++++++--
 3 files changed, 103 insertions(+), 30 deletions(-)

diff --git a/examples/exshexample.tex b/examples/exshexample.tex
index 85b726a..bc4d3ec 100644
--- a/examples/exshexample.tex
+++ b/examples/exshexample.tex
@@ -60,7 +60,7 @@ only={-}
       \item\points[pointsfloatright]{2}pgf (for pgfkeys)
       \item enumitem and similar \points[abbrev,bonus]{1}
       \begin{enumerate}
-        \item paralist
+        \item paralist \thesubex
         \item
           \begin{enumerate}
             \item varioref
@@ -153,7 +153,9 @@ only={-}
   \end{exercise}
   
   Loading varioref enables you to refer to sub-exercises, like 
-  this: Did you do \ref{subex:man2}?
+  this: Did you do \ref{subex:man2}? It is the subexercise
+  \subexnref{subex:man2} and has label \subexlref{subex:man2}.
+
   
   \begin{exercise}[points={many, many},
   firstline={Play around with the options.}]
diff --git a/exercisesheets.sty b/exercisesheets.sty
index 6616f9a..9c8c502 100644
--- a/exercisesheets.sty
+++ b/exercisesheets.sty
@@ -18,8 +18,8 @@
 %\NeedsTeXFormat{LaTeX2e}[1994/12/01]
 
 % don't forget to update the version and date in exercisesheets.tex
-\def\exsh@version{0.10+git}
-\def\exsh@date{2022/01/12}
+\def\exsh@version{0.11}
+\def\exsh@date{2022/02/11}
 
 \ProvidesPackage{exercisesheets}[\exsh@date\space\exsh@version\space Typesetting of exercise sheets]
 \message{`Typesetting of exercise sheets' \exsh@version\space <\exsh@date>}
@@ -43,6 +43,9 @@
 \RequirePackage{currfile}
 \RequirePackage{catchfile}
 
+%we need getrefnumber
+\RequirePackage{refcount}
+
 % configuration keys
 
 \newif\ifexsh@beamer 
@@ -877,8 +880,9 @@
     {\csname the#1\endcsname\autodot\enskip}}%
 }{}
 
-%Do nout use \let here as \label may change before its use
+%Do not use \let here as \label may change before its use
 \def\exsh@autolabel{\label}
+\def\inexlabel{\label}
 
 \newcounter{exsh@pts@cur}
 \newcounter{exsh@ptsbonus@cur}
@@ -1088,6 +1092,7 @@
   %auto labelling is still allowed, but other labels are forbidden
   %here we may use \let as the definition is close to its use
   \let\exsh@autolabel\label
+  \let\inexlabel\label
   \def\label##1{%
     \PackageError{exercisesheets}{\string\label{##1}\space
     inside \string\includeexercise*}{}%
@@ -1153,9 +1158,23 @@
   \labelformat{section}{\pgfkeysvalueof{/exsh/strings/exercise}~\arabic{section}}
 }
 
+
+\let\exsh@subexn\getrefnumber
+
 \ifexsh@patchenumerate
   \AfterPackage*{varioref}{
     \labelformat{enumi}{\arabic{section}.\alph{enumi}}
+    \def\exsh@afterdot#1.#2{#2}%x.y -> y
+    \def\exsh@subexn#1{%
+      \if\getrefnumber{#1}0%
+        0%
+      \else%x.y->y, then inverse \@alph
+        \the\numexpr(\expandafter\expandafter\expandafter%
+        \expandafter\expandafter\expandafter%
+        \expandafter`\expandafter\expandafter\expandafter%
+        \exsh@afterdot\getrefnumber{#1}-`a+1)\relax%
+      \fi%
+    }
   }
   \AfterPackage*{paralist}{
     \setdefaultenum{(a)}{(1)}{i.}{A.}
@@ -1182,6 +1201,29 @@
   }%
 \fi
 
+\newcommand{\subexnref}[1]{\exsh@subexn{#1}}
+\newcommand{\subexlref}[1]{(\@alph{\exsh@subexn{#1}})}
+
+%for now this is not part of the public interface
+\exshset{subtask counter/.initial={enumi}}
+\exshset{subtask environment/.initial={enumerate}}
+\exshset{subtask item/.initial={item}}
+\edef\exsh@subtaskctr{\pgfkeysvalueof{/exsh/subtask counter}}
+\def\exsh@subtaskenv{\pgfkeysvalueof{/exsh/subtask environment}}
+\def\exsh@subtaskitm{\pgfkeysvalueof{/exsh/subtask item}}
+
+%define subex as an alias for enumi
+\expandafter\let\expandafter\c@subex%
+  \csname c@\exsh@subtaskctr\endcsname
+\expandafter\let\expandafter\p@subex%
+  \csname p@\exsh@subtaskctr\endcsname
+\expandafter\let\expandafter\thesubex%
+  \csname the\exsh@subtaskctr\endcsname
+\expandafter\let\expandafter\theHsubex%
+  \csname theH\exsh@subtaskctr\endcsname
+\expandafter\let\expandafter\cl@subex%
+  \csname cl@\exsh@subtaskctr\endcsname
+
 % reset equation numbering for each exercise
 \@addtoreset{equation}{section}
 
@@ -1197,25 +1239,6 @@
   \ignorespaces
 }{}
 
-%we ignore everything before the frist item
-%and process everything afterwards
-\long\def\exsh@processsubtasks#1\item#2\item{%
-\ifstrequal{#2}{}{}{%
-\item #2%
-\csgdef{exsh@restatetask\arabic{enumi}}{#2}%
-\exsh@processsubtasks\item%new "frist" \item to ignore
-}%no whitespace here is crucial for end detecttion
-}
-
-\long\def\exsh@collectedsubtasks#1{
-\begin{enumerate}
-\exsh@processsubtasks#1\item\item
-\end{enumerate}%
-}
-
-\def\exsh@subtaskenv{enumerate}
-\def\exsh@subtaskitm{item}
-\def\exsh@subtaskctr{enumi}
 \newenvironment{subtasks}[1][]{%
   \pgfkeys{exsh,#1}%
   \begin{\exsh@subtaskenv}
@@ -1308,7 +1331,7 @@
     \pgfkeysvalueof{/exsh/solution title font}%
       \pgfkeysvalueof{/exsh/strings/solution} %
       (\pgfkeysvalueof{/exsh/strings/exercise} \arabic{section}%
-        \ifnum\@enumdepth>0\alph{enumi}\fi)%
+        \ifnum\@enumdepth>0\alph{subex}\fi)%
     \end{alertblock}
   }{
     \begin{beamercolorbox}[rounded=true,wd={#1}]%
@@ -1316,7 +1339,7 @@
       \pgfkeysvalueof{/exsh/solution title font}%
       \pgfkeysvalueof{/exsh/strings/solution} %
       (\pgfkeysvalueof{/exsh/strings/exercise} \arabic{section}%
-        \ifnum\@enumdepth>0\alph{enumi}\fi)%
+        \ifnum\@enumdepth>0\alph{subex}\fi)%
     \end{beamercolorbox}
   }
 }
@@ -1367,7 +1390,7 @@
 %     \pgfkeysvalueof{/exsh/solution title font}%
 %     \pgfkeysvalueof{/exsh/strings/solution} %
 %     (\pgfkeysvalueof{/exsh/strings/exercise} \arabic{section}%
-%     \alph{enumi})%
+%     \alph{subex})%
 %   \endblock
   \ifbool{exsh@framed}{\exsh@defersolutiontitletrue}{}
   \ifbool{exsh@defersolutiontitle}{}{%
diff --git a/exercisesheets.tex b/exercisesheets.tex
index 688482d..ea02e92 100644
--- a/exercisesheets.tex
+++ b/exercisesheets.tex
@@ -39,7 +39,7 @@
   breakatwhitespace,
   columns=flexible,
   escapeinside={(*}{*)},
-  mathescape,
+  mathescape=false,
 }
 
 \usepackage[pdfusetitle,colorlinks]{hyperref}
@@ -53,7 +53,7 @@
 \usepackage[english,iso]{isodate}
 \title{The \exsh Package}
 \author{Sebastian Kuhnert\and Frank Fuhlbrück}
-\date{Version 0.10, \printdateTeX{2022/01/12}}
+\date{Version 0.11, \printdateTeX{2022/02/11}}
 
 \begin{document}
 \maketitle
@@ -110,6 +110,7 @@ Frank Fuhlbrück
  \item \texttt{ifthen}
  \item \texttt{amsmath} (for \verb|\numberwithin|)
  \item \texttt{iflualatex}
+ \item \texttt{refcount} (for \verb|\getrefnumber|)
 \end{itemize}
 
 
@@ -480,6 +481,35 @@ if sub-exercises are not simply \verb|\item|s in
 \end{exercise}
 \end{lstlisting}
 
+\subsection{Labels and References within an Exercise}
+While the global reference labels set via varioref (if loaded)
+are nice for references to subexercises far away, always mentioning
+the exercise number seems superfluous. Furthermore, for usage in indices etc. you might want to use the arabic representation instead. This is what the commands \verb|\subexnref| and
+\verb|\subexlref| are designed for. However, both of them still 
+require an ordinary label, which is not allowed in
+exercises loaded with \verb|\loadexercise*|.
+For this purpose \verb|\locallabel| can be used which is just a
+normal label that is not redefined to produce an error.
+Furthermore, we define a counter \verb|subex| (which is
+currently just an alias for enumi, but this might change). You can
+use this counter (alias) with common commands like 
+\verb|\arabic| or \verb|\alph|.
+
+\begin{lstlisting}
+\begin{exercise}
+  \begin{enumerate}
+    \item \locallabel{subex:xisseven} Let $x_{\thesubex}=7$.
+    \item Compute $x_{\subexnref{subex:xisseven}}+3$.
+    \begin{solution}
+      From \subexlref{subex:xisseven} %(a)
+      we know that $x_{\subexnref{subex:xisseven}}$ is $7$ and
+      thus the sum is $10$.
+    \end{solution}
+  \end{enumerate}
+\end{exercise}
+\end{lstlisting}
+
+
 
 \section{Advanced Usage}
 
@@ -735,7 +765,7 @@ Since version 0.11 there is a Lua interface for the exercise
 environment. This interface will offer roughly the same features. 
 Its main purpose will be allowing to reorder sub-exercises more 
 easily and to offer more dynamic options for the display of 
-solutions (one combined solution or single after each sub-
+solutions (one combined solution or single after each sub-%
 exercise). %TODO finish
 
 \begin{lstlisting}
@@ -775,6 +805,24 @@ with solutions.
 
 This also works well in combination with a make file that generates 
 \texttt{solutions.tex}.
+
+
+\section{Changelog}
+\label{sec:changelog}
+
+\begin{itemize}
+  \item[v. 0.11:]  2022-02-11
+      \begin{itemize}
+        \item Local references and the subex counter
+        \item Lua interface (not documented yet, see example and example file)
+        \item Framed solutions can now be fragile, however this 
+        also require Lua\LaTeX (but not using the Lua Interface).
+        \item beamer version is now included (no separate package)
+        \item some bug fixes
+      \end{itemize}
+\end{itemize}
+
+
 \end{document}
 
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-- 
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