eqexpl (13nov18)

git-svn-id: svn://tug.org/texlive/trunk@49151 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 72 insertions, 0 deletions

diff --git a/Master/texmf-dist/tex/latex/eqexpl/eqexpl.sty b/Master/texmf-dist/tex/latex/eqexpl/eqexpl.sty
new file mode 100644
index 00000000000..e07d7d9797b
--- /dev/null
+++ b/Master/texmf-dist/tex/latex/eqexpl/eqexpl.sty
@@ -0,0 +1,72 @@
+\ProvidesPackage{eqexpl}[2018/11/11 v.1]
+\RequirePackage{etoolbox}
+\RequirePackage{calc}
+
+%% Spaces between elements
+\newlength{\eqexplSpaceWidth}
+\newcommand{\eqexplSetSpace}[1]{%
+  \setlength{\eqexplSpaceWidth}{\ifstrempty{#1}{2mm}{#1}}%
+}
+\eqexplSetSpace{}
+
+%% Width of 'intro' (typ. 'where')
+\newcommand{\eqexplSetIntro}[1]{%
+  \def\eqexplIntro{#1}%
+}
+\eqexplSetIntro{}
+
+%% Width of delimiter
+\newcommand{\eqexplSetDelim}[1]{%
+  \def\eqexplDelim{#1}%
+}
+\eqexplSetDelim{---}
+
+%% Width of item
+\newcommand{\eqexplSetItemWidth}[1]{%
+  \def\eqexplItemWidth{#1}%
+}
+\eqexplSetItemWidth{5mm}
+
+%% Align of item
+\newcommand{\eqexplSetItemAlign}[1]{%
+  \def\eqexplItemAlign{#1}%
+}
+\eqexplSetItemAlign{r}
+
+\newlength{\itemWidth}
+\newlength{\leftSideWidth}
+
+\newenvironment{eqexpl}[1][\eqexplItemWidth]{%
+  \let\olditem\item%
+  \setlength{\itemWidth}{#1}%
+  \setlength{\leftSideWidth}{\ifdefempty{\eqexplIntro}{}{\widthof{\eqexplIntro}+%
+                             \eqexplSpaceWidth+}%
+                             \itemWidth+%
+                             \eqexplSpaceWidth+%
+                             \widthof{\eqexplDelim}+%
+                             \eqexplSpaceWidth}%
+  \newtoggle{eqexplFirstItem}%
+  \toggletrue{eqexplFirstItem}%
+  \renewcommand{\item}[1]{%
+    \olditem \makebox[\leftSideWidth]{%
+      \ifdefempty{\eqexplIntro}{}{
+        \makebox[\widthof{\eqexplIntro}][l]{\iftoggle{eqexplFirstItem}{\eqexplIntro}{}}%
+        \hspace{\eqexplSpaceWidth}%
+      }
+      \makebox[\itemWidth][\eqexplItemAlign]{##1}%
+      \hspace{\eqexplSpaceWidth}%
+      \makebox[\widthof{\eqexplDelim}][c]{\eqexplDelim}%
+      \hspace{\eqexplSpaceWidth}%
+    }%
+    \togglefalse{eqexplFirstItem}%
+    \ignorespaces% https://tex.stackexchange.com/a/44062
+  }%
+  \begin{list}{}{\setlength{\parsep}{0pt}%
+  \setlength{\topsep}{0pt}%
+  \setlength{\itemsep}{0pt}%
+  \setlength{\labelsep}{0pt}%
+  \setlength{\leftmargin}{\leftSideWidth}%
+  \setlength{\itemindent}{-\leftSideWidth}}}{%
+  \end{list}
+}
+\endinput