@HenriMenke Hmm, so \detokenize looks for the opening brace of the ⟨general text⟩ with expansion on? That's useful knowledge, if true.

@HaraldHanche-Olsen \detokenize and \scantokens have the same semanticas as a \toks assignment, i.e. they look for <general text>. That means that they expand tokens until they find an explicit opening brace {, discarding spaces and \relax.

Some days ago I've added a link only comment to this answer. The linked page was a statement of the package author, that proofs my the correctness of my previous comments and also tells that the answer is wrong and invites the answer author to help improving the manual. It has been removed by someone. I thought, it was because it was an link only comment.

I've added a new comment where the links is embedded in an explanation. This morning it has been removed again. I do not know who does it and why. But with this kind of censorship I cannot work. If I'm not allowed to tell someone, that his answer is wrong and to proof this and if in such a case even all the correct answers are down-voted, it just makes no sense. So I stop my participation on TeX.SX for now. Thank you for a nice time.

@Schweinebacke Please ask mods before leaving!

@ArtificialOdorlessArmpit That's a secret information, especially if the loss is not significant. (It's officially secret always, but with larger losses, it's usually possible to trace the user.) And remember that the user could have terminated his account himself, it need not be ban or user removal (AFAIK).

@HenriMenke Got it. I'm curious: Do you know why Knuth wanted an explicit { there, instead of just going for a ⟨left brace⟩ character token? It seems counter to the general philosophy of TeX somehow, but I am sure Knuth had good reasons.

@Schweinebacke I agree with @CarLaTeX, the only one who could manually remove a comment is the moderators, so I really suspect that some sort of automation kicked in. Definitely worth checking with @JosephWright

@yo' Thank you! :-)

@Schweinebacke I'll discuss this question/comments with the other mods

@ArtificialOdorlessArmpit Rule One here is: Reputation points are good only for palindrome hunting. :-)

@yo' yes but getting a user banned from the site just so that your rep hits a palindrome might be thought of as excessive.

@DavidCarlisle lol

Hm. I can redefine \pdfpagesattr so that it is issues a warning, but how can one do this with \pdfvariable pagesattr?? Is this even possible? Or should I simply issue a general warning, that the command should not be used? @JosephWright

@JosephWright I got the kernel update. Thanks! Now, In my packages that use expl3, how can I know that expl3 was loaded with driver=dvisvgm?

@AlexG Currently only by checking the internal variable \l__expl_driver_tl: I guess we need a sys-module interface for that

@UlrikeFischer I'm not sure we can do anything at the primitive level: best is to provide an official interface and stick rigidly with that

@JosephWright yes, but the question is how to enforce /nugde and inform the people. I mean I can simply fill \pdfpagesattr at the end of the document with my prop, but this will overwrite everything other packages or user commands did put there and it would be nice if they got at least some warning ...

@UlrikeFischer Can you check the contents?

\documentclass{article}
\begin{document}
\pdfpageattr{foo}
\showthe\pdfpageattr
\end{document}

@UlrikeFischer So check that \the\pdfpageattr is empty?

@JosephWright well currently I update \pdfpagesattr (with s) directly when an entry is added to the prop - there are not so many entries here that it makes sense to delay this, so it is not empty. But I could save the content in a tl and check at the next call and at end document if someone tampered with it. But I guess I should do this at the pdf level and not the driver level.

Can anyone explain what this PostScript code does?

it is being called as, say

[1 1 1] sc

I have a logo from an external source, PDF, that I've converted into eps.

@daleif It does look complicated, that's what it does. ;-)

It has two outline letters ia, that are being filled with white using this line (I can see [1 0 1] sc fills with purple. I need it to be transparent instead.

pdfLastFill not { pdfFillCS setcolorspace } if set th ecolor space if not set

dup /pdfFill exch define pdfFill to be [1 1 1 ]

aload pop put 1 1 1 on the stack

pdfFillXform setcolor use 1 1 1 and whatever pdfFillXform is as arguments to setcolor

Thanks

/pdfLastFill true def /pdfLastStroke false def set those two variables to true and false resoectively

I think I've got it. Just randomly stared outcommenting stuff.

@JosephWright vv

@Schweinebacke Currently I see both

@HenriMenke Actually the opening brace can be implicit: \toks0=\bgroup abc} works. The closing brace has to be explicit, though.

hello, I use \documenclass{amsart} but the title is to long how to make ... in each page please ?

@Vrouvrou \title[short title]{long title}

@PauloCereda Ducklings at our cyclotron. facebook.com/NSCLMSU/videos/284763135736286

@Schweinebacke -- I just looked at the posting in question. There is (still?) a link there among the comments. However, not all comments are shown if there are many of them, only the ones that are upvoted, and the comment with the link wasn't upvoted, so it wouldn't be obvious.

@barbarabeeton no they were deleted and put back (most likely secret mod stuff)

@DavidCarlisle -- I've just seen the question that reports the failure to hyphenate (\textbf{Minimality}), and the answer that proposes that this is a bug. Since ({\bfseries ...}) does hyphenate, this is presumably an explicitly LaTeX problem. Can you confirm this, and maybe provide an explanation? (I think this should be mentioned in the next hyphenation exceptions update.)

@barbarabeeton \textbf adds italic correction 9if it thinks it needs it) It'd need to check the details of how or if \/ next to a word affects the hyphenation pass, no time at the minute

@DavidCarlisle -- Thanks. You've got plenty of time; it will take me some weeks to get the next installment ready.

@DavidCarlisle that's what happens, \/ is inserted and at the begin (with some other char before) it suppress hyphenation: x ({\bfseries\/Minimality})

@UlrikeFischer yes suspected as much, I wonder if it has come up before (it would be surprising if not, we could presumably do \/\nobreak\hskip 0pt or some such dance to get hyphenation back

@DavidCarlisle sounds like a good plan. Should we also make \TeX robust (like \LaTeX)?

@ulrikefischer \protected

@JosephWright not even TeX gets to be defined via Knuth's TeX?:-)

I have this function (expl3) which takes a single token as argument, so naturally its arg-spec is :N. However, when calling the function I have to put braces around the argument because it is, in some cases, a space. What is the correct arg-spec for the function then, :N because it's a single token or :n because of the braces?

@PhelypeOleinik n

@DavidCarlisle Okay. Thanks :-)

@DavidCarlisle well that's an interesting topic for the team list. Should \TeX stay unprotected as a monument for the creator? ;-)

@DavidCarlisle -- But the TeX logo isn't fully uniform when used by DEK; see tug.org/TUGboat/tb07-2/tb15knutlogo.pdf for his own variations. (And for fonts other than computer modern, even more variations are necessary to make it look correct.) On the other hand, built-in robustness isn't considered until LaTeX.

@barbarabeeton yes same is true of latex really, latex companion books had custom logo both for lucida in the body and again for whatever font is on the cover, but it wasn't the latex \protect I was referring to it was Joseph's \protected (that is e-tex protect)

@DavidCarlisle My \protected?

@JosephWright your comment that consisted of just that word

@DavidCarlisle :)

@JosephWright I sorted \pdfpagesattr and added tests for changes and imho it will work reasonably well, but I have no idea how to do it with \pdfinfo ;-(. As far as I can see there is no way to retrieve the current values. I think one simply will have to accept that documents can end with duplicate entries if they use the primitive.

@UlrikeFischer Sounds about right

@UlrikeFischer 'Do not do this'?

@JosephWright yes. Most cases should be fine: they set it through hyperref. Beside this I found around 20 cls and sty (including ltnews and l3build) using \pdfinfo directly. Should be managable (also the info dict is not so relevant anyway).

@AlanMunn thank you 🙏