February 2022 - dev-luatex - NTG Mailing Lists

Luatex 1.12.0 announcement.
by luigi scarso 27 May '23

27 May '23

============================================================== LuaTeX 1.12.0 2020-03-15 ============================================================== This is the release for TeX live 2020. --shell-restricted now forbids loading of dso (dll/so object) Scaled virtual font Aadditional primitives \eTeXglue[stretch|shrink]order for querying order the etex way. Extra features runtoks tex.getmodenames() (as these can differ per engine/version) Permit nested runtoks in more complex situations of nesting (HH) More accurate and correct test for tex.[set|get]math Minor clean-up and bugs fixed -- luigi

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Fix for pdf_literal Lua string / token list conversions
by Michal Vlasák 07 May '23

07 May '23

Hello, take this plain LuaTeX example: \setbox0=\hbox{\pdfextension literal{0 g}} % 1) \directlua{ local literal = tex.getbox(0).head texio.write_nl("log", "literal.data="..literal.data) } \showbox0 % 2) \directlua{ local literal = tex.getbox(0).head literal.data = "test" literal.token = "toks" texio.write_nl("log", "literal.token="..(literal.token or "nil")) } \showbox0 % 3) patch test \directlua{ tex.set("everyjob", "asd") texio.write_nl("log", tex.get("everyjob")) } \bye Expected log output (abridged): 1) literal.data=0 g .\pdfliteral origin{0 g} 2) literal.token=toks .\pdfliteral origin{toks} Actual output: 1) literal.data=data .\pdfliteral origin{0 g} 2) literal.token=characters .\pdfliteral origin <lua data reference 153> In the first case the Lua accessor returns a value which happens to be on top of the stack (the key "data" itself). In the second case an index into TeX memory is misinterpreted as a Lua registry index, so the returned data is essentially garbage. Patch for both issues is attached. I also extended `tokenlist_from_lua` (which is what `nodelib_gettoks` is defined as) to allow an index argument. The previous version used the value on top of the stack, which probably worked for every use currently in LuaTeX, but seemed rather dangerous and subtle. The patch is from git, though it can be applied normally with patch -Np1 < pdf_literal.patch Kind regards, Michal Vlasák

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Make the late_lua node accessible from the executed code
by Marcel Fabian Krüger 01 Mar '22

01 Mar '22

Hi, one issue I regularly encounter with late_lua whatits is that they don't allow the executed code to determine which node is currently executed. Especially this means that attributes and properties can't be reliably accessed and the code can't access related nodes next to the late_lua node. This can be worked around by storing a closure in the data field which captures a reference to the node, but this breaks in hard to debug ways when the node is copied and the copied node has the same code but a different identify. Therefore it would be great if there would be a way to access the currently evaluated late_lua whatsit node. I would have suggested passing this as an argument to the executed function, but that could break compatbility and it would appear odd due to LuaMetaTeX using the second argument of lua functions is different ways. So the attached suggested implemention instead adds a separate function which allows to access this node: node.current_latelua (or node.direct.current_latelua) Best, Marcel

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Weird behavior of \exceptionpenalty
by Marcel Fabian Krüger 25 Feb '22

25 Feb '22

Hi, in an discussion on TeX StackExchange \exceptionpenalty came up and it's current behavior seems a bit odd and is at odds with the documentation: According to the manual: > Because we introduced penalties in discretionary nodes, the exception syntax now > also can take a penalty specification. The value between square brackets is a multiplier for > \exceptionpenalty. Here we have set it to 10000 so effectively we get > 30000 in the example. and then shows the example \hyphenation{z{a-}{-b}{z}{a-}{-b}{z}[3]{a-}{-b}{z}[1]{a-}{-b}{z}z} As the text says, it could be expected that this causes a penalty of 30000. But the currently implemented behavior is different: It assigns a penalty of 10000 to the second discretionary. The reason is that the number in square brackets is only used as a multiplier if exception_penalty is higher than 100000 (sic). For any value of \exceptionpenalty lower or equal to 100000, the number is ignored and the value of \exceptionpenalty is used as is. I'm not sure if this is just a bug (maybe 100000 was supposed to be a upper limit and not a lower limit?) or if this is intended to be used as a marker which later gets replaced by some callback and therefore 100000 was intentionally used as a unrealistic penalty value, but I think that at least the documentation should get fixed. I'm happy to provide a patch for this if you tell me what to implement. I basically see the following options: * Just change the manual to describe the implemented behavior. I think that this would be sad since it makes the feature much less useful since having multiples of badness higher than 100000 seems to have few applications, but this could be picked up by callbacks ansd would be the most compatible option. * Decide that The documentation is more important than the implemented behavior and fix the code to implement the documentation, removing the 100000 criterium (or making it an upper limit instead of a lower one) If 100000 becomes an upper limit, it would also be possible to substract 100000 from exception_penalty before using it to allow emulating the old behavior of using a fixed exception_penalty. (Of course, the opposite: Keep the current code but reduce \exceptionpenalty by 100000 first in the multiplication case could also be done, but IMO that would be a weird interface.) * Add a new flag to select between the new and old behavior or add a new bit to \hyphenationmode. Best, Marcel

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Is \toksapp assignment?
by Petr Olsak 07 Feb '22

07 Feb '22

Hello, If I try: \def\test{test} \afterassignment\test \advance\count0 by2 then \test is processed immediately after the \advance command. But if I do: \afterassignment\test \toksapp 0{xx} \the\toks0 then \test waits to another assignment than \toksapp. It means, that \toksapp <toks> (and friends \gtoksapp etc.) is not assignment. Is it an intention or a bug? Petr Olšák

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What is the current lfs version?
by Jérôme LAURENS 01 Feb '22

01 Feb '22

We can obtain the current lfs version by running luatex '\directlua{tex.write(lfs._VERSION)}\bye' && open texput.pdf Then we must remove texput.pdf and texput.log. This is a bit cumbersome. It would be great if this information could be in the credits: luatex --credits luajittex --credits BTW, is lfs 1.8 planned in forthcoming? (1.7 does not play with windows very well)

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