arraysmacrosmath-mode
I want to make a macro "\mymacro" which has two string variables and returns array.
The two variables are arbitrary string characters and has the same length.
The length of the strings are also arbitrary.
"\mymacro" returns an array whose rows are the string variables.
For example,
\mymacro{abc}{def}
should return
\begin{array}{ccc}
a&b&c\\\hline
d&e&f
\end{array}
Can I make such macro?
Thank you for your cooperation.
This is extensible by adding character translations. It uses the standard array environment.
The idea is to change an input such as |bo|x| into
\multicolumn{1}{|c}{\__fukai_mymacro_char:n{b}} &
\multicolumn{1}{c|}{\__fukai_mymacro_char:n{o}} &
\multicolumn{1}{c|}{\__fukai_mymacro_char:n{x}}
where the last function translates b into a phantom, just to be sure it occupies the same space as the other characters, o into \bigcirc and x into \bigotimes.
The search regular expression means: find zero or one occurrences of | followed by a letter and zero or one occurrences of |. This is replaced by \multicolumn as shown above. At the end of this multiple replacement we need to remove an unwanted trailing &.
The number of columns is computed by examining the arguments and passing +1 for anything that's not |.
\documentclass{article}
\usepackage{array}
\ExplSyntaxOn
\NewDocumentCommand{\mymacro}{mm}
{
\fukai_mymacro:nn { #1 } { #2 }
}
\tl_new:N \l__fukai_mymacro_a_tl
\tl_new:N \l__fukai_mymacro_b_tl
\cs_new_protected:Nn \fukai_mymacro:nn
{
% normalize the input
\__fukai_mymacro_normalize:Nn \l__fukai_mymacro_a_tl { #1 }
\__fukai_mymacro_normalize:Nn \l__fukai_mymacro_b_tl { #2 }
% start the array with the suitable number of columns
\begin{array}
{
* { \int_max:nn { \__fukai_mymacro_count:n { #1 } } { \__fukai_mymacro_count:n { #1 } } } { c }
}
\tl_use:N \l__fukai_mymacro_a_tl
\\ \hline
\tl_use:N \l__fukai_mymacro_b_tl
\end{array}
}
\cs_new_protected:Nn \__fukai_mymacro_normalize:Nn
{
\tl_set:Nn #1 { #2 }
\regex_replace_all:nnN
{ (\|)??([[:alpha:]])(\|?) } % |<char>|
{ \c{multicolumn}\{1\}\{\1 c \3\}\{ \c{__fukai_mymacro_char:n}\{\2\} \} \& }
#1
\regex_replace_once:nnN { \& \Z } { } #1
}
% count the non-| characters
\cs_new:Nn \__fukai_mymacro_count:n
{
\int_eval:n { 0 + \str_map_function:nN { #1 } \__fukai_mymacro_ischar:n }
}
\cs_new:Nn \__fukai_mymacro_ischar:n
{
\str_if_eq:nnF { #1 } { | } { +1 }
}
% the translations
\cs_new:Nn \__fukai_mymacro_char:n
{
\str_case:nn { #1 }
{
{b}{\phantom{\bigcirc}}
{o}{\bigcirc}
{x}{\bigotimes}
}
}
\ExplSyntaxOff
\begin{document}
$\mymacro{|b|b|ooo|x|}{oooooo}$
\bigskip
$\mymacro{|bo|x|}{o|x|b}$
\bigskip
$
\begin{array}{ccc}
\multicolumn{1}{|c}{} & \multicolumn{1}{c|}{\bigcirc} & \multicolumn{1}{c|}{\bigotimes}
\\\hline
\multicolumn{1}{c|}{\bigcirc} & \multicolumn{1}{c|}{\bigotimes} & \multicolumn{1}{c}{}
\end{array}
$
\end{document}
In the image, the third array is “hand made” to show the result is the same as with the second array done with \mymacro.
Best Answer
You can iterate over the list the tricky bit is to avoid adding a
&at the end here I do add it but use\omitto avoid generating a visible empty column (with an over-long\hline)