How to write a command to format different letters?

Question

I hope I can have a command MyFormatter, which can make letters p and k bold and make letters m and t italic.

For example:

\MyFormatter{Supermarket}

will output as follows:

Supermarket

How to write the command \MyFormatter in LaTeX?

score 7 · Accepted Answer · edited Apr 13 '17 at 12:34

Here's a straightforward solution using expl3. If you need it to work in subgroups \MyFormatter{Supermarket and \MakeUppercase{Supermarket}} you can check this solution.

\usepackage{xparse}
\ExplSyntaxOn
\NewDocumentCommand \myformatter { +m } { \xmllmx_myformatter:n { #1 } }
\cs_new_protected:Npn \xmllmx_myformatter:n #1
 {
  \tl_set:Nn \l_tmpa_tl { #1 }
  \tl_replace_all:Nnn \l_tmpa_tl { p } { \textbf{p} }
  \tl_replace_all:Nnn \l_tmpa_tl { k } { \textbf{k} }
  \tl_replace_all:Nnn \l_tmpa_tl { m } { \textit{m} }
  \tl_replace_all:Nnn \l_tmpa_tl { t } { \textit{t} }
  \tl_use:N \l_tmpa_tl
 }
\ExplSyntaxOff

score 6 · Answer 2 · answered Jun 30 '16 at 10:34

It's easy and flexible with regular expressions:

\documentclass{article}
\usepackage{xparse,l3regex}

\ExplSyntaxOn
\NewDocumentCommand{\myformatter}{m}
 {
  \tl_set:Nn \l_tmpa_tl { #1 }
  \regex_replace_all:nnN
   { ([kp]+) } { \c{textbf}\cB\{ \1 \cE\} }
   \l_tmpa_tl
  \regex_replace_all:nnN
   { ([mt]+) } { \c{textit}\cB\{ \1 \cE\} }
   \l_tmpa_tl
  \tl_use:N \l_tmpa_tl
 }
\ExplSyntaxOff

\begin{document}

\myformatter{Supermarket}

\end{document}

Steven B. Segletes · Answer 3 · 2016-06-30T11:36:35.000

4

An approach using catcodes that works if the \MyFormatter appears in the clear and is not part of an argument. As egreg pointed out in this regard, \mbox{\MyFormatter{Supermarket}} fails.

However, I jokingly retort in my comment that the way to get around the fail-case is to put the \mbox inside the MyFormatter, not the other way around. Of course, the new drawback with this "fix" is that the "m" of \mbox is now active, and so an additional \let is required: \let\MBOX\mbox\MyFormatter{\MBOX{Supermarket}}.

Finally, wipet comments that one could argue that the problem lies in the definition of \mbox, in that \hbox{\MyFormatter{Supermarket}} does not suffer the same problem.

\documentclass{article}
\let\BB\textbf
\let\II\textit
\let\CC\catcode
\let\AC\active
\let\SVP p \let\SVK k \let\SVM m \let\SVT t
\def\CODESON{\CC`p=\AC  \CC`k=\AC  \CC`m=\AC  \CC`t=\AC }
\def\CODESOFF{\CC`p=11 \CC`k=11 \CC`m=11 \CC`t=11 }
\CODESON
\def p{\BB{\SVP}}
\def k{\BB{\SVK}}
\def m{\II{\SVM}}
\def t{\II{\SVT}}
\CODESOFF
\newcommand\MF[1]{#1\CODESOFF}
\newcommand\MyFormatter{\CODESON\MF}
\begin{document}
Supermarket \MyFormatter{Supermarket} Supermarket

\mbox{\MyFormatter{Supermarket}} fails, but

\let\MBOX\mbox\MyFormatter{\MBOX{Supermarket}} works
\end{document}

edited Jun 30 '16 at 11:36

answered Jun 30 '16 at 10:53

Steven B. Segletes

237,551

Try \mbox{\MyFormatter{Supermarket}} – egreg Jun 30 '16 at 11:00
@egreg DRAT! Again, I say DRAT! – Steven B. Segletes Jun 30 '16 at 11:03
@egreg Of course, since \MyFormatter{Supermarket} doesn't hyphenate, why would one need to put it into an \mbox? ;^) – Steven B. Segletes Jun 30 '16 at 11:14
And of course, you are using the wrong syntax! Clearly, it is: \let\MB\mbox\MyFormatter{\MB{Supermarket}}. Isn't that obvious?? 8^b – Steven B. Segletes Jun 30 '16 at 11:16
2

But \hbox{\MyFormater{Supermarket}} works. This is LaTeX problem that \mbox is defined as macro with parameter. It needs not. – wipet Jun 30 '16 at 11:20
@wipet I know you are aware of the differerence between \hbox and \mbox (with parameter or not, that's a different topic). LaTeX users aren't and advertising \hbox is not the best service to them. Besides, \mbox was just an example; any command with argument would suffer of the same problem, including plain TeX ones. – egreg Jun 30 '16 at 12:04
1

Advertising \hbox is best service to them because they come to know that there are other approaches than only LaTeX. :-). Or they can define \def\mbox{\leavevmode\hbox} – wipet Jun 30 '16 at 12:09

score 2 · Answer 4 · edited Jun 30 '16 at 14:31

2

For example using OPmac:

\input opmac

\def\MyFormatter{\afterassignment\MyFormatterA \def\tmpb}
\def\MyFormatterA{\replacestrings{p}{{\bf p}}\replacestrings{k}{{\bf k}}%
   \replacestrings{m}{{\it m}\/}\replacestrings{t}{{\it t}\/}\tmpb}

\MyFormatter{Supermarket}

\bye

edited Jun 30 '16 at 14:31

Manuel

27,118

answered Jun 30 '16 at 12:23

wipet

74,238

How to write a command to format different letters?

4 Answers4