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Diffstat (limited to 'tex/.texmf/tex/generic/pgfplots/liststructure/pgfplotsdeque.code.tex')
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diff --git a/tex/.texmf/tex/generic/pgfplots/liststructure/pgfplotsdeque.code.tex b/tex/.texmf/tex/generic/pgfplots/liststructure/pgfplotsdeque.code.tex new file mode 100644 index 0000000..7a524f1 --- /dev/null +++ b/tex/.texmf/tex/generic/pgfplots/liststructure/pgfplotsdeque.code.tex @@ -0,0 +1,125 @@ +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +% +% This is a helper package with an elementary double-ended-queue +% (deque) datastructure, +% featuring O(1) index access and O(N) creation, deletion, copy. +% +% The following macros are supplied: +% +% \pgfplotsdequenewempty +% \pgfplotsdequecopy +% \pgfplotsdequepushback +% \pgfplotsdequepopfront +% \pgfplotsdequecheckempty +% \pgfplotsdequeforeach +% +% Copyright 2007/2008 by Christian Feuersänger. +% +% This program is free software: you can redistribute it and/or modify +% it under the terms of the GNU General Public License as published by +% the Free Software Foundation, either version 3 of the License, or +% (at your option) any later version. +% +% This program is distributed in the hope that it will be useful, +% but WITHOUT ANY WARRANTY; without even the implied warranty of +% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +% GNU General Public License for more details. +% +% You should have received a copy of the GNU General Public License +% along with this program. If not, see <http://www.gnu.org/licenses/>. +% +% +% +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +% IMPLEMENTATION NOTES: +% I allocate an array which provides storage capacity and two pointers +% (indices) into that array. +% +% The deque is stored as +% - an array: \csname pgfpldq@<name>\endcsname +% - the pointers: +% \csname pgfpldq@<name>@beg\endcsname +% \csname pgfpldq@<name>@end\endcsname (one after the end) +% +% ATTENTION: <name> may NOT be a control sequence! +% this is in contrast to my other container structures. + + +% Allocates a new, empty deque #1. +% +% #1 the name of a deque (NO control sequence!) +% #2 is an integer denoting the maximum capacity. For now, this +% capacity is fixed afterwards and denotes the maximum number of +% entries. +\def\pgfplotsdequenewempty#1{% + \pgfutil@ifnextchar\capacity{% + \pgfplotsdequenewempty@{#1}% + }{% + \pgfplots@error{Expected \string\capacity\{the capacity\} after \string\pgfplotsdequenewempty...}% + \pgfplotsdequenewempty@{#1}\capacity{100}% + }% +}% +\def\pgfplotsdequenewempty@#1\capacity#2{% + \pgfplotsarrayresize{pgfpldq@#1}{#2}% + \pgfutil@namedef{pgfpldq@#1@beg}{0}% + \pgfutil@namedef{pgfpldq@#1@end}{0}% +}% + +\def\pgfplotsdequecopy#1\to#2{% + \pgfutil@namelet{pgfpldq@#1@beg}{pgfpldq@#2@beg}% + \pgfutil@namelet{pgfpldq@#1@end}{pgfpldq@#2@end}% + \pgfplotsarraycopy{pgfpldq@#1}\to{pgfpldq@#2}% +}% + +\def\pgfplotsdequepushback#1\to#2{% + \pgfplotsarrayset{\csname pgfpldq@#2@end\endcsname}\of{pgfpldq@#2}\to{#1}% + \c@pgfplotsarray@tmp=\csname pgfpldq@#2@end\endcsname + \advance\c@pgfplotsarray@tmp by1 + \ifnum\c@pgfplotsarray@tmp=\pgfplotsarraysizeof{pgfpldq@#2} + \c@pgfplotsarray@tmp=0 + \fi + \expandafter\edef\csname pgfpldq@#2@end\endcsname{\the\c@pgfplotsarray@tmp}% + \pgfplotsdequeifempty{#2}{\pgfplots@error{Error: \string\pgfplotsdeque\space capacity has been reached - it was too small. Sorry, I didn't write auto-enlargement...}}{}% +}% + +\def\pgfplotsdequepopfront#1\to#2{% + \pgfplotsarrayselect{\csname pgfpldq@#1@beg\endcsname}\of{pgfpldq@#1}\to{#2}% + \c@pgfplotsarray@tmp=\csname pgfpldq@#1@beg\endcsname + \advance\c@pgfplotsarray@tmp by1 + \ifnum\c@pgfplotsarray@tmp=\pgfplotsarraysizeof{pgfpldq@#1} + \c@pgfplotsarray@tmp=0 + \fi + \expandafter\edef\csname pgfpldq@#1@beg\endcsname{\the\c@pgfplotsarray@tmp}% +}% + +% invokes #2 if deque '#1' is empty and '#3' if it is not empty. +\def\pgfplotsdequeifempty#1#2#3{% + \ifnum\csname pgfpldq@#1@beg\endcsname=\csname pgfpldq@#1@end\endcsname\relax + #2% + \else + #3% + \fi +}% + + +\long\def\pgfplotsdequeforeach#1\as#2#3{% + \c@pgfplotsarray@tmp=\csname pgfpldq@#1@beg\endcsname + \long\def\pgfplotsdequeforeach@next{\pgfplotsdequeforeach@iter{#1}{#2}{#3}}% + \pgfplotsdequeforeach@next +}% +\long\def\pgfplotsdequeforeach@iter#1#2#3{% + \ifnum\c@pgfplotsarray@tmp=\csname pgfpldq@#1@end\endcsname + \def\pgfplotsdequeforeach@next{}% + \else + \pgfplotsarrayselect\c@pgfplotsarray@tmp\of pgfpldq@#1\to#2% + \edef\pgfplotsdequeforeach@{\the\c@pgfplotsarray@tmp}% + #3\relax + \c@pgfplotsarray@tmp=\pgfplotsdequeforeach@ + \advance\c@pgfplotsarray@tmp by1 + \ifnum\c@pgfplotsarray@tmp=\pgfplotsarraysizeof{pgfpldq@#1} + \c@pgfplotsarray@tmp=0 + \fi + \fi + \pgfplotsdequeforeach@next +}% |