%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%
% This is file 'loops-pokayoke1.tex', version 1.3, 2013/05/15.             %
%                                                                          %
% This package and accompanying files may be distributed and/or            %
% modified under the conditions of the LaTeX Project Public License,       %
% either version 1.3 of this license or any later version. The latest      %
% version of this license is in http://www.latex-project.org/lppl.txt      %
% and version 1.3 or later is part of all distributions of LaTeX           %
% version 2005/12/01 or later.                                             %
%                                                                          %
% The LPPL maintenance status of this software is 'author-maintained'.     %
%                                                                          %
% This software is provided 'as it is', without warranty of any kind,      %
% either expressed or implied, including, but not limited to, the          %
% implied warranties of merchantability and fitness for a particular       %
% purpose.                                                                 %
%                                                                          %
% The following files constitute the loops bundle and must be              %
% distributed as a whole:                                                  %
%                                                                          %
%  README, loops.sty, loops-pokayoke1.                                     %
%                                                                          %
% Copyright (c) 2010-2013 Ahmed Musa (amusa22@gmail.com).                  %
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++%

\documentclass{article}
\usepackage{tikz}
\usepackage{loops}

% See the README file for more examples.

%++++++++++++++++++++++++++ Examples +++++++++++++++++++++++++%

% There are two types of sequences in the following list, i.e.,
% {\pi0,\pi0.5,\pi...,\pi3} and {0\pi,0.5\pi,...\pi,3\pi}
%
\newforeach\x in {\pi0,\pi0.5,\pi...,\pi3,0\pi,0.5\pi,...\pi,3\pi}{%
  \edef\y{\skvexpandonce\x}%
}


\begin{document}
\begin{tikzpicture}[every node/.style=draw]
\node (A) at (0,0) {A};
\node (B) at (2,0) {B};
\node (C) at (4,0) {C};
\node (D) at (6,0) {D};
\newforeach \n [remember=\n as \lastn initially A] in {B,C,D}
  \draw [->] (\lastn) -- (\n);
\end{tikzpicture}

\par\bigskip

\foreachfox [remember=#1 as \x initially A] {B,C,D,E,F,G,H} {%
  $\overrightarrow{\x#1}$\iflastfox.\else,\space\fi
}

\foreachfox [remember=#1 as \x initially A] {B,...,H} {%
  $\overrightarrow{\x#1}$\iflastfox.\else,\space\fi
}

% (C1) and [F1] will be picked as single elements:
\foreachfox [list type=tsv,remember=#1 as \x initially A] {B(C1)DE[F1]GH} {%
  $\overrightarrow{\x#1}$\iflastfox.\else,\space\fi
}

\end{document}


%++++++++++++++++++++++++++ Examples +++++++++++++++++++++++++%

\documentclass{article}
\usepackage{tikz,loops}
\usetikzlibrary{arrows,shapes,backgrounds,fit}
\usepackage{tkz-graph}

\begin{document}
\begin{tikzpicture}
\SetVertexNormal[Shape=rectangle,FillColor=lightgray,LineWidth=2pt]
\SetUpEdge[lw=1.5pt,color=black]
\foreach \y in {1,2,3,4} {
  \foreach \x / \a in {1/a,2/b,3/c,4/d} {
    \Vertex[L=\y \a,x=2*\x,y=2*\y]{\x\y}
  }
}
\newforeach \x/\y/\z/\s in {
  11/23/32/,14/33/22/,41/33/22/,44/44/23/,21/33/42/13,
  24/12/32/43,31/12/23/43,34/13/22/42,12/33//,22/43//,
  32/13//,42/23//
}{
  \Edge(\x)(\y)
  \ifx\z\empty\else\Edge(\x)(\z)\fi
  \ifx\s\empty\else\Edge(\x)(\s)\fi
}
\end{tikzpicture}
\end{document}

\def\alist{}
\newforeach\x in {%
  2pt_A,4pt_A,...pt_A,10pt_A
}{%
  \xdef\alist{\alist\ifx\alist\@empty\else,\fi\x}%
}
\show\alist

\let\alist\@gobble
\newforeach\x in {%
  A_2pt,A_4pt,A_...pt,A_10pt, A_20pt,A_24pt,A_...pt,A_40pt
}{%
  \xdef\alist{\alist,\x}%
}
\show\alist

\let\alist\@gobble
\foreachfox {%
  A_2pt,A_4pt,A_...pt,A_10pt, A_20pt,A_24pt,A_...pt,A_40pt%
}{%
  \xdef\alist{\alist,#1}%
}
\show\alist

\let\alist\@gobble
% The key 'hide parameters' makes it possible to use parameter
% characters in the callback without doubling them.
\newforeach[hide parameters] \x in {1,...,10} do {%
  \edef\cmda#1{\x*#1}%
  \newforeach[hide parameters] \y in {A,...,M} do {%
    \xdef\alist{\alist,\x(\y)}%
    \edef\cmdb#1{\x*\y*#1}%
  }%
}
\show\alist