Am 01.05.2015 um 20:41 schrieb Sam Ḥilluc <shilluc@gmx.com>:

On 2015-05-01 19:38, Otared Kavian wrote:
Hi,

You have several commands in ConTeXt doing what you are seeking to do: please look at the examples below:

%%% begin do-if-inset.tex
\starttext
\type{\doifinset{A}{A,B,C}{should go}:} \doifinset{A}{A,B,C}{should go}

\type{\doifinset{D}{A,B,C}{should go}:}  \doifinset{D}{A,B,C}{should participate}


\type{\doifnotinset{}{A,B,C}{not in the set}:} \doifnotinset{}{A,B,C}{not in the set}

\type{\doifnotinset{D}{A,B,C}{not in the set}:} \doifnotinset{D}{A,B,C}{not in the set}

\doifinsetelse{D}{A,B,C}{it is in the set}{it is not in the set}

\define\test{B}

\type{\doifinsetelse{\test}{A,B,C}{\test\ is in the set}{\test\ is not in the set}}

\doifinsetelse{\test}{A,B,C}{\test\ is in the set}{\test\ is not in the set}
\stoptext
%%% end do-if-inset.tex

Best regards: OK

This works for testing if a given character is in a set, but how can I retrieve
that character just after the defined macro.

To give an example, a macro that adds a dot if the next character is not a
comma.

   \MyMacro{text1} text2     ->      text1. text2
   \MyMacro{text1}, text2    ->      text1, text2

You can use the \doifelsenextchar command to check the character after your command.

\define[1]\MyMacro
  {\doifelsenextchar{,}
     {#1}
     {#1. }}

\starttext

\MyMacro{left} right

\MyMacro{left}, right

\stoptext


The limitation of this method is that you check only for one character at a time
and when want to check for more you have to use multiple \doifelsenextchar lines.

\doifelsenextchar{,}
  {...}
  {\doifelsenextchar{.}
     {...}
     {...}}

Wolfgang