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_suite_focus=true
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
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