Am 06.02.2014 um 19:29 schrieb Pablo Rodriguez <oinos@gmx.es>:

On 02/06/2014 12:57 AM, Wolfgang Schuster wrote:
Am 05.02.2014 um 19:50 schrieb Pablo Rodriguez <oinos@gmx.es>:

Hi Hans,

I have the following sample:

\setuptyping[option=TEX]
\starttext
\starttyping
\input zapf % knuth
\stoptyping
\stoptext

The percent character is in bold font and gray color, but the rest of
the commented text isn’t.
[...]

http://pragma-ade.com/general/magazines/mag-1102.pdf

Many thanks for your reply, Wolfgang.

After reading the document, I think it could be achieved with:

\definefontfamily[mainface][mono][DejaVu Sans Mono]
\setupbodyfont[mainface]
\defineprocessor[myescape][style=bold,color=gray, left=\%]
\setuptyping[TEX][escape=myescape->{\%}]
\starttext
\startTEX
This is a c%omment.

% And this is another one.

\command
 [with colored]
 {brackets}
\stopTEX
\stoptext

But this doesn’t work. I must be missing something obvious.

What am I doing wrong here?

Many thanks for your help,

You have to add a comma after \letterpercent. You should also be careful with
the text in the comments because commands are expanded, e.g. take a look
at the \TeX in the comment.

\setupbodyfont[dejavu]

\defineprocessor[myescape][style=\ttbf,color=gray,left={\letterpercent}]

\setuptyping[TEX][escape=myescape->{\letterpercent,}]

\starttext
\startTEX
This is \TeX\ code % and this is a \TeX\ comment.
\stopTEX
\stoptext

Wolfgang