[Dev-luatex] .BEILMOPS or how I stopped worrying and love Open Source

[David Kastrup]

"Jonathan Sauer" <Jonathan.Sauer at silverstroke.com> writes:

> [\unexpanded vs \detokenize]
>
>> > 2.	\unexpanded introduces spaces after control sequences.
>> 
>> Why wouldn't \detokenize do the same?  Wait, it does:
>>
>> > At least in the context of \directlua.
>> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>> 
>> I guess that this may be the real reason.
>
> I thought a bit about this, and I think that it is quite useful if
> \detokenize does not introduce spaces when used in \directlua, as
> opposed to \unexpanded, since sometimes (i.e. when used as a set in
> lpeg.S) spaces are completely undesired.
>
> Of course, in these situations \string could be used as an
> alternative.  But since \detokenize is equivalent (at least as I
> understand it)

Your understanding is wrong.

etex
This is pdfTeXk, Version 3.141592-1.40.3 (Web2C 7.5.6)
 %&-line parsing enabled.
**\message{\detokenize{\x}a}
entering extended mode
\x a
*\message{\string\x a}
\xa
*\end
No pages of output.
Transcript written on texput.log.

> to prefixing each token with \string, \detokenize should not introduce
> spaces. IMO.

I disagree.  I don't think that \detokenize should behave differently
within \directlua.  Not least of all since "within" is very fuzzy to
define when macro expansion is involved.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum