new latex package abraces (3sep12)

git-svn-id: svn://tug.org/texlive/trunk@27880 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 111 insertions, 0 deletions

diff --git a/Master/texmf-dist/tex/latex/abraces/abraces.sty b/Master/texmf-dist/tex/latex/abraces/abraces.sty
new file mode 100644
index 00000000000..3c13e82cea5
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+++ b/Master/texmf-dist/tex/latex/abraces/abraces.sty
@@ -0,0 +1,111 @@
+\ProvidesPackage{abraces}% http://ctan.org/pkg/abraces
+  [2012/08/24 v1.0 Arbitrary and asymmetric braces]
+\newif\if@overload
+\DeclareOption{overload}{\@overloadtrue}
+\ProcessOptions
+\newsavebox{\bracebox}% stores content contained under/over brace
+
+\newcommand{\newbracespec}[2]{% Add a new brace specification based on existing ones
+  \@defbracecharcode{#1}{\@genbrace#2\@nnil\@genbrace}
+}
+% Brace components
+\newcommand{\bracescript}[1]{{% Add a script above/below an over-/underbrace
+  \let\@@bfil\@@bunfil% Make line leaders into void/empty leaders
+  \let\@use@rl@se\phantom% Phantomize some brace components
+  \makebox[\wd\bracebox]{$\genbrace{#1}$}% Place the text in a box of width \bracebox
+}}
+\def\@@bunfil{\leaders\hbox{\ }\hfill}% Empty filler
+\newcommand{\bracefil}[1]{%
+  \csname brace@char@#1'\endcsname%
+}
+\def\@@bfil{\leaders \vrule \@height \ht\z@ \@depth \z@ \hfill}% default brace filler
+%\def\bfil{\@@bfil}%
+%\def\@bLfil{\@@bfil}% left leader filler
+%\def\@bRfil{\@@bfil}% right leader filler
+\def\aupbracefill#1{$\m@th\setbox\z@\hbox{$\braceld$}\genbrace{#1}$}
+\def\adownbracefill#1{$\m@th\setbox\z@\hbox{$\braceld$}\genbrace{#1}$}
+
+% Repetition structure. Reference:
+%   Repeat command n times?
+%   http://tex.stackexchange.com/q/16189/5764
+% Alternatively
+%   \RequirePackage{expl3}% http://ctan.org/pkg/expl3
+%   \ExplSyntaxOn
+%   \cs_new_eq:NN \Repeat \prg_replicate:nn
+%   \ExplSyntaxOff
+
+\newcommand{\Repeat}[1]{%
+  \expandafter\@Repeat\expandafter{\the\numexpr #1\relax}%
+}
+\def\@Repeat#1{%
+    \ifnum#1>0
+        \expandafter\@@Repeat\expandafter{\the\numexpr #1-1\expandafter\relax\expandafter}%
+    \else
+        \expandafter\@gobble
+    \fi
+}
+\def\@@Repeat#1#2{%
+    \@Repeat{#1}{#2}#2%
+}
+% Taken from mathtools package (http://ctan.org/pkg/mathtools)
+\newcommand{\aunderbrace}[2][l1D1r]{%
+  \begin{lrbox}{\bracebox}$\displaystyle{#2}$\end{lrbox}%
+  \mathop{\vtop{\m@th\ialign{##\crcr
+    $\hfil\displaystyle{#2}\hfil$\crcr
+    \noalign{\kern.7\fontdimen5\textfont2\nointerlineskip}%
+    \aupbracefill{#1}\crcr\noalign{\kern.5\fontdimen5\textfont2}}}}\limits}
+\newcommand{\aoverbrace}[2][L1U1R]{%
+  \begin{lrbox}{\bracebox}$\displaystyle{#2}$\end{lrbox}%
+  \mathop{\vbox{\m@th\ialign{##\crcr
+    \noalign{\kern.5\fontdimen5\textfont2}%
+    \adownbracefill{#1}\crcr
+    \noalign{\kern.7\fontdimen5\textfont2\nointerlineskip}%
+  $\hfil\displaystyle{#2}\hfil$\crcr}}}\limits}
+
+% Parsing structure. Reference:
+%   Parsing a macro argument character-by-character for conditional execution
+%   http://tex.stackexchange.com/q/33197/5764
+
+\let\@use@rl@se\relax
+\def\@defbracecharcode#1{% Macro to define brace character "codes"
+  \@namedef{brace@char@#1}%
+}
+\@defbracecharcode{L}{\@use@rl@se\braceld\@genbrace}% Left down
+\@defbracecharcode{R}{\@use@rl@se\bracerd\@genbrace}% Right down
+\@defbracecharcode{l}{\@use@rl@se\bracelu\@genbrace}% Left up
+\@defbracecharcode{r}{\@use@rl@se\braceru\@genbrace}% Right up
+\@defbracecharcode{U}{\@use@rl@se\braceru\@use@rl@se\bracelu\@genbrace}% Tip up
+\@defbracecharcode{D}{\@use@rl@se\bracerd\@use@rl@se\braceld\@genbrace}% Tip down
+\@defbracecharcode{0}{\@@bunfil\@genbrace}% Do nothing
+\@defbracecharcode{1}{\@@bfil\@genbrace}% 1 filler
+\@defbracecharcode{2}{\@@bfil\@@bfil\@genbrace}% 2 fillers
+\@defbracecharcode{3}{\@@bfil\@@bfil\@@bfil\@genbrace}% 3 fillers
+\@defbracecharcode{4}{\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 4 fillers
+\@defbracecharcode{5}{\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 5 fillers
+\@defbracecharcode{6}{\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 6 fillers
+\@defbracecharcode{7}{\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 7 fillers
+\@defbracecharcode{8}{\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 8 fillers
+\@defbracecharcode{9}{\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@@bfil\@genbrace}% 9 fillers
+\@defbracecharcode{@}{\@firstofone@go}% Insert arbitrary stuff
+\@defbracecharcode{!}{\@firstofone@len}% Insert a leader of specific length
+\@defbracecharcode{*}{\@repeat@num@times}% Repeat stuff a number of times
+
+\newcommand{\@firstofone@go}[1]{#1\@genbrace}%
+\newcommand{\@firstofone@len}[1]{\hb@xt@#1{\@@bfil}\@genbrace}%
+\newcommand{\@repeat@num@times}[2]{\Repeat{#1}{\@genbrace#2\@nnil}\@genbrace}%
+
+\newcommand{\@genbrace}[1]{%
+  \ifx\@nnil#1\relax\else
+    \@nameuse{brace@char@#1\expandafter}%
+  \fi%
+}
+\newcommand{\genbrace}[1]{%
+  \@genbrace#1\@nnil%
+}
+
+% If package was loaded with \usepackage[overload]{abraces}
+\if@overload
+  \let\overbrace\aoverbrace
+  \let\underbrace\aunderbrace
+\fi
+\endinput
\ No newline at end of file