On Thu, Mar 10, 2022 at 9:25 AM Ikumi Keita wrote:

Hello LuaTeX developers,

I have a few questions I'd like to ask you. In log message, luatex engine produces slightly different error context from what pdftex does. Here is a sample code: ---------------------------------------------------------------------- Nullam eu ante vel est convallis dignissim. } Nulla posuere. \bye ---------------------------------------------------------------------- When I process this file by luatex, it results in the following error: ------ luatex result ------------------------------------------------- ! Too many }'s. l.1 Nullam eu ante vel est convallis dignissim. } Nulla posuere. ---------------------------------------------------------------------- On the other hand, pdftex results in: ------ pdftex result ------------------------------------------------- ! Too many }'s. l.1 Nullam eu ante vel est convallis dignissim. } Nulla posuere. ---------------------------------------------------------------------- The output of luatex is shifted by two characters compared with that of pdftex. (I'm using TeX Live 2021.)

This discrepancy confuses preview-latex (subsystem of AUCTeX), which depends on the precise position of the log messages: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=54200

I'm not sure whether this behavior is a bug or not, but is it something I can expect to be fixed? If not, is there any workaround to make the output the same as pdftex? (e.g. command line option)

I will check, but , in case , for sure no fix for this texlive: 1) the "write to stdout/stderr/log " apparatus is complex/complicated, it's very easy to break something; 2) pdftex and luatex are different engines, it is expected that some outputs are anf will be different. Example: %%test.tex %% replace <TEXT> with %% a very long line in japanese text, longer than 79 "chars", without newline. \wlog{% <TEXT> } \bye You can compare the log with pdftex and luatex. These are the kind of things that should be addressed at the format level, if possible, or modifying the parsing method, if possible, being open to the fact: "different engines, different output". -- luigi

Hello LuaTeX developers,

I have a few questions I'd like to ask you. In log message, luatex engine produces slightly different error context from what pdftex does. Here is a sample code: ---------------------------------------------------------------------- Nullam eu ante vel est convallis dignissim. } Nulla posuere. \bye ---------------------------------------------------------------------- When I process this file by luatex, it results in the following error: ------ luatex result ------------------------------------------------- ! Too many }'s. l.1 Nullam eu ante vel est convallis dignissim. } Nulla posuere. ---------------------------------------------------------------------- On the other hand, pdftex results in: ------ pdftex result ------------------------------------------------- ! Too many }'s. l.1 Nullam eu ante vel est convallis dignissim. } Nulla posuere. ---------------------------------------------------------------------- The output of luatex is shifted by two characters compared with that of pdftex. (I'm using TeX Live 2021.)

This discrepancy confuses preview-latex (subsystem of AUCTeX), which depends on the precise position of the log messages: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=54200

I'm not sure whether this behavior is a bug or not, but is it something I can expect to be fixed? If not, is there any workaround to make the output the same as pdftex? (e.g. command line option) Because file and token input follows a different route in luatex an dcan also be influenced by lua mix-in (which itself can result in intermediate flushing or position adjustments of log outpout) it is best to assume that it's not the same as in pdftex. To a large extent is it

On 3/10/2022 9:18 AM, Ikumi Keita wrote: the same but there are definitely differences. In this case I'd strip / ignore spaces before comparing. So here it probably more a side effect than a bug and 'fixing' this might as well introduce side effects someplace else. (there are various position states wrt logging: terminal as well as log file and they can run in sync or out of sync depending on the situation and log related parameters, as well as writing from lua or tex, combined with configuration setting ... so we have sort of a complex commprimis) Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------