Hello, Max: As I promised you this morning, I had time this evening to read more carefully all your remarks in the last mail. And now I can answer you with more basis. In my particular case, it is not necessary to consider any of the seven possible problems you describe from highest to lowest probability. The question you asked me in the first paragraph about "interesting" features in my ConTeXt code is the key. When I uncomment grid=yes in my \setuplayout, lwc makes its real appearance on the scene. I suppose that in other documents than mine, i.e. less complex, this performance would be a success. But in my file it is, considering my current aesthetic requirements, a failure. This is because for me grid=yes is a non-negotiable part of my code. As I told you this morning when I sent you my pdf without the module activated, but with the layout my way, I understand that lwc can have problems with a text whose chapters have capital letters and small caps on the first page with less text than on the following pages; with long quotations that involve paragraphs of different layout and separated from the main text; with more than one footnote in a row, with a bibliography at the end with French indentation; with vertical spaces separating two lines within the same chapter when in the dummy text there is a supposed change of scene within the narrative; with etc. etc., etc., etc... Anyway, after uncommenting grid=yes again, I will send you the log file, as you asked me. By the way, I do get some "Widow/Orphan NOT removed on page..." in spite of the rest of "successes" that move the final lines of my pages away from the result I would like, and that you have seen in the pdf I sent you this morning. Do you want the new pdf with lwc actually acting on my file? Then you can get a better idea of what I mean by the end of some pages when I comment grid=yes (apart from the mischief that happens with the horizontal spaces in some paragraphs of the bibliographic section). Or, if you prefer, and you need more feedback, I can send you my current code to use it as a test bench for " daring " texts. Greetings, edu El 27/4/22 a las 9:14, Max Chernoff escribió:
Quick question before I begin: are you using any especially "interesting" ConTeXt features? By "interesting" I mean things like grid typesetting, pagecolumns, bidirectional text, etc. I haven't tested lwc with every possible ConTeXt feature, so there may be some adverse interaction. If you are using something like this, try disabling it and see if that solves anything (then let me know so that I can fix it!)
On 2022-04-26 3:45 a.m., Eduardo Bohoyo wrote:
I can see "modules > 'lua-widow-control' is loaded".
But, luckily, I can also see this:
open source > level 2, order 4, name '/opt/luametatex/texmf-modules/tex/context/third/lua-widow-control/t-lua-widow-control.mkxl'
resolvers > lua > loading file '/opt/luametatex/texmf-modules/tex/luatex/lua-widow-control/lua-widow-control.lua' succeeded close source > level 2, order 4, name '/opt/luametatex/texmf-modules/tex/context/third/lua-widow-control/t-lua-widow-control.mkxl'
module > lua-widow-control > Already enabled
Ok, so this is good; lwc is for sure being loaded successfully.
No line such as "Widow/orphan detected. Attempting to delete".
I see interleaved new groups with the same line always repeating a warning message throughout the whole file. In short, there are 613 new lines with the message "luatex warning > tex: left parfill skip is gone". But I didn't give it any importance, because I interpreted that they could be inherent to the module.
Well this at least narrows the issue down quite a bit. Lwc runs in pretty much two stages: when a paragraph has finished being broken by TeX, lwc saves the paragraph. The second stage is ran just before each time the output routine is triggered so that lwc can remove the widows and orphans.
Due to an lwc bug, the first stage results in the "left parfill skip" warning being printed twice for each paragraph. Normally this is quite annoying, but here it is good -- we know for sure that the first stage is running just fine.
It is the second stage where you should get the "Widow/orphan detected" message, but this isn't happening. The code here is at lwc.lua:362-388.
Here is a list of all possible reasons, in order of likelihood, why "Widow/orphan detected" wouldn't be printed when there is actually a widow or orphan:
(Just listing all of these to make sure that *I* don't forget anything. I'd say that 1 and 2 are the only ones that are actually likely -- you can probably ignore all of the others)
1. "\clubpenalty" and/or "\widowpenalty" are either zero or infinite
In these cases, lwc can't distinguish a widow or orphan from other penalties, so it doesn't do anything. You can check for this with
\showthe\widowpenalty \showthe\clubpenalty
some time after "\starttext". This will print the values to the log file. The values should probably be "1", but things like "150" and "5000" are fine too. If you see negative values, "0", or values greater than ten thousand, then something is wrong here.
2. Something is "hiding" the widow/orphan penalties from lwc.
Something like "\vadjust{\penalty X}" or the e-TeX "\-penalties" commands could potentially do this.
One potential solution for (a subset of) this problem would be to modify lwc.mkxl to insert "\directsetup{*reset}" at line 52, to get:
\startsetups[*default] \directsetup{*reset} \clubpenalty=\lwcparameter{orphanpenalty} \widowpenalty=\lwcparameter{widowpenalty} \displaywidowpenalty=\lwcparameter{widowpenalty} \brokenpenalty=\lwcparameter{brokenpenalty} \stopsetups
If that doesn't do anything, keep the above modifications but also insert
\setups[*default]
after "\starttext" in your test document.
3. Lwc hasn't saved any paragraphs since the last output routine.
Since we know that the first stage is running, this shouldn't be possible unless there is a weird bug somewhere else.
4. A weird engine/format bug.
The LMTX test file was successful on Debian x86_64 three days ago
https://github.com/gucci-on-fleek/lua-widow-control/runs/6144354147?check_su...
so something quite weird would have to be going on here.
5. Something is overwriting the "pre_output_filter" callback.
Now this is an interesting one. ConTeXt has frozen most of the core engine callbacks, but "pre_output_filter" is unfrozen and unassigned. There is a ConTeXt interface for most of the other callbacks, but here I need to fallback to the low-level interface. With this interface, you can only register a single callback, so it is possible that some other package is overwriting the callback. To test this, the very beginning of your document should look like: \usemodule[lua-widow-control] \startluacode lwc.callbacks.disable_box_warnings.enable = function () end lwc.callbacks.disable_box_warnings.disable = function () end callback = nil \stopluacode
If you get a really strange error from some other package/module (not lwc), then this may be the issue. Fairly unlikely.
6. The values of "\club/widowpenalty" change between the paragraph being typeset and the output routine being triggered.
I can't imagine this happening for *every* page in a document except unless you are specifically trying to do this. Fairly unlikely.
7. You have the exact Lua code lwc.callbacks.remove_widows.disable() written in your document. Exceedingly unlikely.
On the other hand, the distribution and size of my paragraphs take great care that their "design" optimises the module's goodness, except, of course, for the first pages of each of the nine dummy text chapters (they start at a third of a page).
Well as long as you aren't seeing
Widow/Orphan NOT removed
in your log file then your text should be fine.
I will go over the lua-widow-control.pdf document once more in case there is a tiny detail I am missing, but I think, if I keep going at this pace, I will end up learning it by heart.
There's probably not too much else in there -- and the documentation is a bit of a mess right now anyways.
---
If none of the above solutions solved anything, then what I'll need to debug further will be for you to insert
\setuplwc[debug=true]
into your document right after you load lwc. Then, send me the full log file -- probably as a link since it will be quite large.
Thanks.
-- Max