On Tue, Jul 7, 2020 at 6:21 PM Jairo A. del Rio
Thank, Wolfgang! Both methods work, but both fail with the following example:
\pushmacro\unexpanded \let\unexpanded\normalunexpanded \input xstring \popmacro\unexpanded \starttext \StrGobbleLeft{bcdef}{4} \stoptext
The log says:
tex error > tex error on line 6 in file ./tests.tex: ! This can't happen (prefixed command)
<argument> \unexpanded {
f}
\xs_execfirst #1#2->#1
However, some others work.
As I said, the internals of `xstring` still use \unexpanded which, after you do \popmacro\unexpanded, will mean e-TeX's \protected, rather than \unexpanded, which are quite different. To be on the safe side, you'd need to wrap every `xstring` command in \pushmacro\unexpanded \let\unexpanded\normalunexpanded <xstring stuff> \popmacro\unexpanded to make sure that \unexpanded means what `xstring` expects. The *proper* way to make `xstring` work in ConTeXt would be something like Circuitikz does: \ifcsname normalunexpanded\endcsname \let\pgfcircutil@unexpanded\normalunexpanded \else \let\pgfcircutil@unexpanded\unexpanded \fi then use \pgfcircutil@unexpanded in the code, which will always have the same meaning. That, of course, requires an update to `xstring`. Phelype