[Dev-luatex] Assignments in Lua

Hello, take the following PlainTeX example (as always ;-): %&luatex \catcode`@=11 \def\log#1{\immediate\write\sixt@@n{#1}} \let~\space \tracingassigns1 \tracingrestores1 \tracingonline1 \count@=5 \log{Before:~~~~~~~~~~~~~~~~~\the\count@} \begingroup \directlua0{tex.count["count@"]=23} \log{In group:~~~~~~~~~~~~~~~\the\count@} \endgroup \log{After \string\endgroup:~~~~~~~~\the\count@} \bye This results in: This is LuaTeX, Version snapshot-0.25.3-2008051713 (Web2C 7.5.6) (Assignments.tex{into \tracingonline=1} {changing \count255=92} {into \count255=5} Before: 5 {reassigning [no_local_whatsits]=0} {reassigning [no_local_dirs]=0} {changing \count255=5} {into \count255=23} In group: 23 {restoring \count255=5} After \endgroup: 5 ) (see the transcript file for additional information) No pages of output. Transcript written on Assignments.log. Now, a few months and betas ago, assignments made inside Lua to tex.count et cetera were always global (see my posting on August 14th 2007 on this mailing list). Now it seems that they respect grouping. Is this meant to stay or is it an unintended side-effect of some other change? Looking into the source ('set_tex_count_register' in luatex.web), it seems that this change is deliberate. If it is a feature (which I'd be very grateful for, since it would simplify a lot of things), how do I perform \global assignments in Lua? As far as I can see from the source, I cannot pass an optional third parameter to tex.setcount: tex.setcount( register, <number> value, <boolean> global) I would try my hand at a patch to implement this, but unfortunately, I cannot find the function prototype for set_tex_count_register. A sketch: - Modify et.al. so that 'a' is no longer a constant local variable, but a parameter. - In ltexlib.c, check for an optional boolean using , then pass either zero (local/false) or four (global/true) as the third parameter to et.al. - Add a call to @ in et.al. so that \globaldefs works correctly. I'm not sure about the last point, though, since it would mean that TeX would influence Lua's behaviour. OTOH, adding that code would make Lua and TeX behave consistently. Another thing: Setting an attribute using tex.attribute does not seem to add the attribute to nodes, contrary to setting it in TeX. Most likely this is because in TeX, the attribute list cache is reset (luatex.web lines 28106f) and the number of the largest used attribute register is adjusted, which is not done in Lua (luatex.web lines 34646ff). Adding if (j)>max_used_attr then max_used_attr:=(j); attr_list_cache:=cache_disabled; in luatex.web in function 'set_tex_attribute_register' before line 34650 ('word_define(j+attribute_base,v);') fixes this (for both 'tex.setattribute(...)' and 'tex.attribute = ...'). And while we're at it: In luatex.wb line 27777, help1("I'll pretend you didn't say \long or \outer or \global."); should be help1("I'll pretend you didn't say \long or \outer or \global or \protected."); Jonathan