I have two comma delimited lists:
ListA(a,b,c,d,e,f,g)
and
ListB(name1,name2,name3,name4,name5)
I would like to iterate through both lists at the same time, something like:
loop
readvalue from list A
readvalue from list B
create new variable aname1{}
repeat
Iteration should stop, if it reaches to the end of either lists.
A solution which goes through all elements:
\documentclass{article}
\usepackage{pstricks}
\psforeach{\A}{a,b,c,d,e,f,g}{%
\psforeach{\B}{name1,name2,name3,name4,name5}{%
\expandafter\xdef\csname\A\B\endcsname{Def: \A,\B}}}
\begin{document}
\csname aname1\endcsname
\csname ename4\endcsname
\end{document}
Make sure comma isn't active, otherwise this won't work. For example, the following fails. Also, make sure there are no spurious spaces in your lists.
\begingroup
\catcode`\,=13
\def\x{\endgroup
\psforeach{\A}{a,b,c,d,e,f,g}{%
\psforeach{\B}{name1,name2,name3,name4,name5}{%
\expandafter\xdef\csname\A\B\endcsname{Def: \A,\B}%
}%
}%
}
\x
xstring you can check a given list: \def\ListA{a,b,c,d,e,f,g}
\StrCount{\ListA,}{,}[\Number]
The macro \Number returns 7
–
Feb 27 '11 at 14:57
\psforeach can't do auto-completion \psforeach\A{a,...,g}?
– Ahmed Musa
Oct 07 '12 at 00:57
You can map a function on two comma-separated list, using the code below. It also lets you "zip" two comma separated lists together. All this is expandable, e.g. suitable for use in a \write statement, etc. Or rather, it is expandable if the function you map is itself expandable. See the end of the code for an example suited to your case.
\documentclass{minimal}
\usepackage{expl3}
\ExplSyntaxOn
% Spaces are now ignored, and `_` and `:` can be used in macro names.
%
% `\tl_if_either_empty_ii:nn` tests whether either one of two token
% lists is empty.
%
\prg_new_conditional:Npnn \tl_if_either_empty_ii:nn #1 #2 {p,T,F,TF} {
\tl_if_empty:nTF {#1} {\prg_return_true:} {
\tl_if_empty:nTF {#2} {\prg_return_true:} {\prg_return_false:}
}
}
% Function to zip two clist together, e.g.,
% {1,2,3,4,5} {aa,bb,cc,d} -> {1}{aa}, {2}{bb}, {3}{cc}, {4}{d}
% It stops when reaching the end of any of the two lists. For people who
% care: it is `f`-expandable.
%
\cs_new:Npn \clist_zip_ii:nn #1 #2 {
\clist_zip_ii_aux:nw {} #1, \q_mark, #2, \q_mark.
}
\cs_new:Npn \clist_zip_ii_aux:nw #1 #2, #3 \q_mark, #4, #5 \q_mark. {
\tl_if_either_empty_ii:nnTF {#3} {#5} {
#1 {#2}{#4}
}{
\clist_zip_ii_aux:nw {#1 {#2}{#4},} #3 \q_mark, #5 \q_mark.
}
}
\cs_generate_variant:Nn \clist_zip_ii:nn {VV}
% To map a function `#3` of two arguments onto the zipped result,
% we do something similar, essentially replacing commas by `#1` in
% the output.
\cs_new:Npn \clist_map_zip_ii:nnN #1 #2 #3 {
\clist_map_zip_ii_aux:Nnw #3 {} #1, \q_mark, #2, \q_mark.
}
\cs_new:Npn \clist_map_zip_ii_aux:Nnw #1 #2 #3, #4 \q_mark, #5, #6 \q_mark. {
\tl_if_either_empty_ii:nnTF {#4} {#6} {
#2 #1{#3}{#5}
}{
\clist_map_zip_ii_aux:Nnw #1 {#2 #1{#3}{#5}} #4 \q_mark, #6 \q_mark.
}
}
\cs_generate_variant:Nn \clist_map_zip_ii:nnN {VV}
% ======================= Your comma separated lists ==================
% All those `g` mean `global`.
\clist_new:N \g_my_first_clist
\clist_new:N \g_my_second_clist
\clist_gput_right:Nn \g_my_first_clist {a,b,c,d,e,f}
\clist_gput_right:Nn \g_my_second_clist {1,2,3,4,5}
\cs_new:Npn \my_create_variable:nn #1 #2 {
\iow_term:n {Creating~variable~``#1 name #2''} % Message to the terminal
\tl_new:c {#1 name #2}
}
\clist_map_zip_ii:VVN \g_my_first_clist
\g_my_second_clist
\my_create_variable:nn
% Restore the usual behaviour of space, colon and underscore.
\ExplSyntaxOff
\begin{document}
\end{document}
n lists rather than 2.
– Bruno Le Floch
Feb 27 '11 at 14:25
map_function on the zipped clist. For that we need either a map_function_unbraced, which leaves the argument unbraced, or a map_function:Nn which maps a bunch of tokens rater than just a function (I'd prefer that.) Then \clist_map_function:Nn \l_tmpa_clist {\exp_after:wN \foo:nn \use:n} will map a function of two variables on a zipped clist. --- Do you generate_variant ... {V} and then rename to N?
– Bruno Le Floch
Mar 01 '11 at 07:18
If you don't mind global assignments and to interleave the lists you can use the \foreach macro of pgffor:
\documentclass{article}
\usepackage{pgffor}
\begin{document}
\foreach \name/\value in {namea/a,nameb/b,namec/c} {%
\global\expandafter\def\csname\name\expandafter\endcsname\expandafter{\value}%
}
% Test:
\show\namea \show\nameb \show\namec
\end{document}
Otherwise you need to program you own loop which removes a value from each list. Just look e.g. how the \@for loop is defined in latex.ltx.
Here is another solution using simple iteration. I'm sorry that the code is not very clean.
\documentclass{article}
\makeatletter
\long\def\getfirst@#1,#2\@@#3{\def#3{#1}}
\long\def\getfirst#1#2{%
\def\temp{#2}%
\expandafter\getfirst@\temp,\@nil\@@#1}
\def\@nil@{\@nil}
\long\def\getrest@#1,#2\@@#3{\def\temp{#2}%
\ifx\@nil@\temp
\let#3\undefined
\else
\expandafter\getrest@@\temp#3
\fi}
\long\def\getrest@@#1,\@nil#2{\def#2{#1}}
\long\def\getrest#1#2{%
\def\temp{#2}%
\expandafter\getrest@\temp,\@nil\@@#1}
\long\def\split#1#2#3{%
\def\temp{#3}%
\expandafter\getfirst@\temp,\@nil\@@#1
\def\temp{#3}%
\expandafter\getrest@\temp,\@nil\@@#2}
\begin{document}
% your list
\def\listA{a,b,c,d,e,f}
\def\listB{X,Y,Z,W}
\newif\ifloop
\def\testloop{%
\ifx\listA\undefined \loopfalse \fi
\ifx\listB\undefined \loopfalse \fi
\ifloop}
\looptrue
\loop
% extract list
\expandafter\split\expandafter\firstofA\expandafter\restofA\expandafter{\listA}
\expandafter\split\expandafter\firstofB\expandafter\restofB\expandafter{\listB}
% show progress
{\tt
\meaning\firstofA \qquad \meaning\restofA\qquad
\meaning\firstofB \qquad \meaning\restofB\par}%
% do definition
\expandafter\edef \csname TT\firstofA\endcsname {\firstofB}%
% iteration
\let\listA\restofA
\let\listB\restofB
\testloop\repeat
result:\\
\verb=\TTa= is \TTa\\
\verb=\TTb= is \TTb\\
\verb=\TTc= is \TTc\\
\verb=\TTd= is \TTd
\end{document}
Even though the question is a bit older, the general problem still occurs from time to time. The following generic solution defines the macro \forlistlooptwo, which works as etoolbox' \forlistloop. There are two extensions: First, it expects two comma separated lists instead of one and second, the handler function expects two arguments instead of one.
Use lists of equal lengths and avoid spaces and semicolons in the lists and in the elements, respectively, as I wanted to keep the code short.
\documentclass{minimal}
\usepackage{xstring}
\usepackage{etoolbox}
\def\forlistlooptwo#1#2#3{%
\ifboolexpr{test{\IfSubStr{#2}{,}} and test{\IfSubStr{#3}{,}}}{%
% Evaluate first pair and call back with reduced lists if there are at least two elements in each list..
\forlistlooptwohelper{#1}#2;#3;%
}{%
\ifboolexpr{test{\notblank{#2}} and test{\notblank{#3}}}{%
% Evaluate last pair, if there is one element in each list.
#1{#2}{#3}%
}{}%
}%
}
\def\forlistlooptwohelper#1#2,#3;#4,#5;{%
% Call the handler with the first pair as the two arguments.
#1{#2}{#4}%
% Call the loop macro again with the lists reduced by the first pair.
\forlistlooptwo{#1}{#3}{#5}%
}
\begin{document}
\def\createVariableFromPair#1#2{%
\csdef{#1#2}{}%
}%
\forlistlooptwo{\createVariableFromPair}{a,b,c}{name1,name2,name3}%
\ifcsdef{bname2}{true}{false}, \ifcsdef{bname3}{true}{false}
\end{document}
The example outputs as demanded: true, false
For convenience, arrayjobx package can do the trick, although the data are not separated by commas.
\documentclass{article}
\usepackage{arrayjobx}
\usepackage{ifthen}
\newcounter{ind}
\begin{document}
\newarray\Names
\newarray\Primes
\readarray{Names}{two&three&five&seven&eleven}
\readarray{Primes}{2&3&5&7&11&13}
\noindent
\setcounter{ind}{1}%
\whiledo{\value{ind}<10}{%
% show progress
\theind: \Names(\theind)---\Primes(\theind)\\
% do definitions
\checkNames(\theind)\let\temp\cachedata
\checkPrimes(\theind)%
\expandafter\xdef\csname\temp\endcsname{\cachedata}%
% step index counter
\stepcounter{ind}}
\two, \three, \five, \seven, \eleven
\end{document}
Here is a solution that gives exit conditions as the OP indicated in the question. Also, active commas are welcome and spurious spaces in the list are trimmed.
\documentclass{article}
\usepackage{loops}
\def\ftoks{f}
\newforeach \x [
item counter = \xc, exit when = \ifx\x\ftoks\fi
] in {a,...,g} do {%
\let\xcc\xc
\newforeach [
count in = \yc all \y satisfying \ifnum\y>10\fi,
loop stopper = \ifnum\y>20\fi
] \y in {1,...,30} {%
\skvcsdef{#1##1}{Items: #1, ##1}%
}%
\let\xc\xcc
}
\begin{document}
Numbers: {\tt\string\xc}: \xc, {\tt\string\yc}: \yc
\skvcsuse{a1}
\skvcsuse{e10}
\end{document}
aname1,aname2,...,aname5,...,gname1,...,gname5? – Will Robertson Feb 27 '11 at 12:55