no more xparse requirement

boxgrab.dtx

@@ -78,7 +78,6 @@ and the derived files           boxgrab.pdf and
 \newcommand*\boxgrab@version{1.0}
 \ProvidesPackage{boxgrab}
   [\boxgrab@date\ v\boxgrab@version\ utilities to get an argument as a box]
-\RequirePackage{xparse}
 %</pkg>
 % \fi
 %
@@ -116,43 +115,57 @@ and the derived files           boxgrab.pdf and
 %       \marg{next}\oarg{save args}
 %   \end{syntax}
 %   Grabs the next braced argument inside of the box \meta{box register}. The
-%   box is of \meta{box type}, which should be either \cs{hbox} or \cs{vbox}.
-%   \meta{inject pre} will be injected at the beginning of the box and can
-%   affect its contents, \meta{inject post} will be injected after the box but
-%   can't be affected by stuff inside of \meta{inject pre}. Unless the \meta{*}
-%   is given leading and trailing spaces will be stripped from the box. After
-%   the box is read in \meta{next} will be executed. The usage is therefore
-%   similar to the one of \cs{@ifstar}. You can specify arguments which should
-%   be given to \meta{next} using \meta{save args}. The stuff you provide in
-%   \meta{save args} will be given as is to \meta{next}, so if you want to give
-%   an argument you should delimit it like with braces, like \verb|[{#1}]|, or
-%   if you want to give two arguments, like \verb|[{#1}{#2}]|.
-%
-%   All assignments are made local. Currently it is not save to nest macros
-%   which use \cs{boxgrab}.
+%   box is of \meta{box type}, which should be one of \cs{hbox} or \cs{vbox} or
+%   \cs{vtop}. \meta{inject pre} will be injected at the beginning of the box
+%   and can affect its contents, \meta{inject post} will be injected after the
+%   box but can't be affected by stuff inside of \meta{inject pre}. Unless the
+%   \meta{*} is given leading and trailing spaces will be stripped from the box.
+%   After the box is read in \meta{next} will be executed. The usage is
+%   therefore similar to the one of \cs{@ifstar}. You can specify arguments
+%   which should be given to \meta{next} using \meta{save args}. The stuff you
+%   provide in \meta{save args} will be given as is to \meta{next}, so if you
+%   want to give an argument you should delimit it with braces, like
+%   \verb|[{#1}]|, or if you want to give two arguments, like
+%   \verb|[{#1}{#2}]|.
 % \end{function}
 %
+%   \smallskip
+%   All assignments are made local. Currently it is not safe to nest macros
+%   which use \cs{boxgrab}. It should become save if you're macros use
+%   \cs{boxgrab} inside of a group, so the local assignments don't affect the
+%   outer macro.
+%
+%   \cs{boxgrab} uses \cs{afterassignment} and \cs{aftergroup} to do its magic.
+%   The \cs{afterassignment} should be safe where it is used, the
+%   \cs{aftergroup} is used inside of the boxed argument before any contents are
+%   inserted.
+%
+%   Since \cs{boxgrab} works by setting a boxregister using \cs{setbox} (and a
+%   bunch of temporary macros), it is of course not expandable and defined
+%   \cs{protected}. Bear in mind that macros created with \cs{boxgrab} are
+%   not expandable.
+%
 % \section{Useless Example!}
 %
 % First we need to reserve us a box register for this example:
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % \newsavebox\ourbox
-%\end{verbatim}
+% \end{verbatim}
 %
 % Next we define a macro which takes some arguments and uses our macro:
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % \newcommand\examplecmd[2]
 %   {%
 %     \begingroup
 %     \boxgrab\ourbox[\itshape]\hbox[ \sffamily is]\examplecmdOut[{#1}{#2}]
 %   }
-%\end{verbatim}
+% \end{verbatim}
 %
 % And we need our helper macro which is executed after \cs{boxgrab}:
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % \newcommand\examplecmdOut[3]
 %   {%
 %     \begin{tabular}[t]{@{}ll@{}}
@@ -163,7 +176,7 @@ and the derived files           boxgrab.pdf and
 %     \end{tabular}%
 %     \endgroup
 %   }
-%\end{verbatim}
+% \end{verbatim}
 %
 % The result is a macro that takes two ordinary arguments, after those a
 % box in horizontal mode and finally another ordinary argument. If we use this
@@ -187,20 +200,20 @@ and the derived files           boxgrab.pdf and
 %   }%
 % \examplecmd{Hi,}{my}{\verb|name|}{Steve!}
 % \end{center}
-% One can see, that the \verb|\sffamily is| of \meta{inject post} is not
-% affected by the |\itshape| in \meta{inject pre}.
-% The used code to generate that table was:
+% One can see that the \verb|\sffamily is| of \meta{inject post} is not affected
+% by the |\itshape| in \meta{inject pre}. The used code to generate that table
+% was:
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % \examplecmd{Hi,}{my}{\verb|name|}{Steve!}
-%\end{verbatim}
+% \end{verbatim}
 %
 % \section{Useful Example?}
 %
 % This example provides a macro which typesets its mandatory argument in a block
 % of a definable number of lines, it is meant for a single paragraph.
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % % Getting a box register:
 % \newsavebox\RectangleBox
 % % Defining the main macro
@@ -218,16 +231,20 @@ and the derived files           boxgrab.pdf and
 %     \end{minipage}%
 %     \endgroup
 %   }
-%\end{verbatim}
+% \end{verbatim}
 %
-% And a usage example of our new macro (with the \pkg{duckuments} package
+% As you can see, this macro uses \cs{boxgrab} in a group delimited by
+% \cs{begingroup} and \cs{endgroup}. It should therefore be safe to nest it
+% inside other macros using \cs{boxgrab}.
+%
+% Finally a usage example of our new macro (with the \pkg{duckuments} package
 % loaded):
 %
-%\begin{verbatim}
+% \begin{verbatim}
 % \begin{center}
 %   \Rectangle[9]{\blindduck}
 % \end{center}
-%\end{verbatim}
+% \end{verbatim}
 % Results:
 % \newsavebox\RectangleBox
 % \newcommand\Rectangle[1][4]
@@ -260,62 +277,75 @@ and the derived files           boxgrab.pdf and
 %    \begin{macrocode}
 \@ifdefinable{\if@boxgrab@spaces@}{\newif\if@boxgrab@spaces@}
 \newcommand*\boxgrab@args{}%
-\NewDocumentCommand \boxgrab { s m +O{} m +O{} m }
+\newcommand\boxgrab@def[2]
   {%
-    \IfBooleanTF{#1}
-      {\@boxgrab@spaces@true}
-      {\@boxgrab@spaces@false}%
-    \def\boxgrab@name{#2}%
-    \if@boxgrab@spaces@
-      \def\boxgrab@into@pre{#3}%
+    \@ifdefinable#1{\protected\def#1{#2}}%
+  }
+\newcommand\boxgrab@def@step[4]
+  {%
+    \@ifdefinable#1{\protected\def#1##1{\def#2{##1}\boxgrab@opt#3#4}}%
+  }
+\long\def\boxgrab@check@bracket #1[#2\endboxgrab@check@bracket
+  {%
+    \if\relax\detokenize{#2}\relax
+      \expandafter\@firstoftwo
     \else
-      \def\boxgrab@into@pre{#3\ignorespaces}%
+      \expandafter\@secondoftwo
     \fi
-    \def\boxgrab@type{#4}%
-    \def\boxgrab@into@post{#5}%
-    \def\boxgrab@final{#6}%
+  }
+\protected\def\boxgrab@opt#1#2%
+  {%
     \@ifnextchar[
-      {\boxgrab@get@args}
-      {\def\boxgrab@args{}\boxgrab@a}
+      {\boxgrab@opt@get#1#2}
+      {\def#1{}#2}%
   }
-\newcommand \boxgrab@get@args {}
-\long\def\boxgrab@get@args#1]
+\long\def\boxgrab@opt@get#1#2#3]%
   {%
-    \expandafter\boxgrab@get@args@a\expandafter{\@gobble#1}%
+    \expandafter\boxgrab@opt@get@a\expandafter{\@gobble#3}#1#2%
   }
-\newcommand \boxgrab@get@args@a [1]
+\protected\long\def\boxgrab@opt@get@a#1#2#3%
   {%
     \boxgrab@check@bracket #1[\endboxgrab@check@bracket
-      {\def\boxgrab@args{#1}\boxgrab@a}%
-      {\boxgrab@get@args@grabon{#1]}}%
+      {\def#2{#1}#3}
+      {\boxgrab@opt@get@b#2#3{#1]}}%
   }
-\newcommand \boxgrab@get@args@grabon {}
-\long\def\boxgrab@get@args@grabon#1#2]
+\protected\long\def\boxgrab@opt@get@b#1#2#3#4]%
   {%
-    \boxgrab@check@bracket #2[\endboxgrab@check@bracket
-      {\def\boxgrab@args{#1#2}\boxgrab@a}
-      {\boxgrab@get@args@grabon{#1#2]}}%
+    \boxgrab@check@bracket #4[\endboxgrab@check@bracket
+      {\def#1{#3#4}#2}
+      {\boxgrab@opt@get@b#1#2{#3#4]}}%
   }
-\newcommand \boxgrab@check@bracket {}
-\long\def\boxgrab@check@bracket #1[#2\endboxgrab@check@bracket
+\boxgrab@def\boxgrab@unpack
   {%
-    \if\relax\detokenize{#2}\relax
+    \expandafter\ifx\boxgrab@type\hbox
       \expandafter\@firstoftwo
     \else
       \expandafter\@secondoftwo
     \fi
+    \unhbox
+    \unvbox
+    \boxgrab@name
   }
-\newcommand* \boxgrab@a
+\boxgrab@def\boxgrab
+  {%
+    \@ifstar
+      {\@boxgrab@spaces@true\boxgrab@a}
+      {\@boxgrab@spaces@false\boxgrab@a}%
+  }
+\boxgrab@def@step\boxgrab@a\boxgrab@name\boxgrab@into@pre\boxgrab@b
+\boxgrab@def@step\boxgrab@b\boxgrab@type\boxgrab@into@post\boxgrab@c
+\boxgrab@def@step\boxgrab@c\boxgrab@final\boxgrab@args\boxgrab@d
+\boxgrab@def\boxgrab@d
   {%
     \afterassignment\boxgrab@intermediate
     \setbox\boxgrab@name\boxgrab@type
   }
-\newcommand*\boxgrab@intermediate
+\boxgrab@def\boxgrab@intermediate
   {%
     \aftergroup\boxgrab@after
     \boxgrab@into@pre
   }
-\newcommand*\boxgrab@after
+\boxgrab@def\boxgrab@after
   {%
     \if@boxgrab@spaces@
       \setbox\boxgrab@name\boxgrab@type
@@ -333,21 +363,11 @@ and the derived files           boxgrab.pdf and
     \fi
     \expandafter\boxgrab@final@exp@args\expandafter{\boxgrab@args}%
   }
-\newcommand*\boxgrab@unpack
-  {%
-    \csname
-      un%
-      \expandafter\expandafter\expandafter\@gobble
-      \expandafter\string\boxgrab@type
-    \endcsname
-    \boxgrab@name
-  }
 \newcommand\boxgrab@final@exp@args[1]
   {%
     \def\boxgrab@args{}%
     \boxgrab@final#1%
   }
-
 %    \end{macrocode}
 %
 %    \begin{macrocode}