% language=uk \environment luatex-style \environment luatex-logos \startcomponent luatex-tex \startchapter[reference=tex,title={The \TEX\ related libraries}] \section{The \type {lua} library} \subsection{\LUA\ version} This library contains one read|-|only item: \starttyping s = lua.version \stoptyping This returns the \LUA\ version identifier string. The value is currently \directlua {tex.print(lua.version)}. \subsection{\LUA\ bytecode registers} \LUA\ registers can be used to communicate \LUA\ functions across \LUA\ chunks. The accepted values for assignments are functions and \type {nil}. Likewise, the retrieved value is either a function or \type {nil}. \starttyping lua.bytecode[ n] = f lua.bytecode[ n]() \stoptyping The contents of the \type {lua.bytecode} array is stored inside the format file as actual \LUA\ bytecode, so it can also be used to preload \LUA\ code. Note: The function must not contain any upvalues. Currently, functions containing upvalues can be stored (and their upvalues are set to \type {nil}), but this is an artifact of the current \LUA\ implementation and thus subject to change. The associated function calls are \startfunctioncall f = lua.getbytecode( n) lua.setbytecode( n, f) \stopfunctioncall Note: Since a \LUA\ file loaded using \type {loadfile(filename)} is essentially an anonymous function, a complete file can be stored in a bytecode register like this: \startfunctioncall lua.bytecode[n] = loadfile(filename) \stopfunctioncall Now all definitions (functions, variables) contained in the file can be created by executing this bytecode register: \startfunctioncall lua.bytecode[n]() \stopfunctioncall Note that the path of the file is stored in the \LUA\ bytecode to be used in stack backtraces and therefore dumped into the format file if the above code is used in \INITEX. If it contains private information, i.e. the user name, this information is then contained in the format file as well. This should be kept in mind when preloading files into a bytecode register in \INITEX. \subsection{\LUA\ chunk name registers} There is an array of 65536 (0--65535) potential chunk names for use with the \type {\directlua} and \type {\latelua} primitives. \startfunctioncall lua.name[ n] = s s = lua.name[ n] \stopfunctioncall If you want to unset a \LUA\ name, you can assign \type {nil} to it. \section{The \type {status} library} This contains a number of run|-|time configuration items that you may find useful in message reporting, as well as an iterator function that gets all of the names and values as a table. \startfunctioncall info = status.list() \stopfunctioncall The keys in the table are the known items, the value is the current value. Almost all of the values in \type {status} are fetched through a metatable at run|-|time whenever they are accessed, so you cannot use \type {pairs} on \type {status}, but you {\it can\/} use \type {pairs} on \type {info}, of course. If you do not need the full list, you can also ask for a single item by using its name as an index into \type {status}. The current list is: \starttabulate[|lT|p|] \NC \rmbf key \NC \bf explanation \NC \NR \NC pdf_gone \NC written \PDF\ bytes \NC \NR \NC pdf_ptr \NC not yet written \PDF\ bytes \NC \NR \NC dvi_gone \NC written \DVI\ bytes \NC \NR \NC dvi_ptr \NC not yet written \DVI\ bytes \NC \NR \NC total_pages \NC number of written pages \NC \NR \NC output_file_name \NC name of the \PDF\ or \DVI\ file \NC \NR \NC log_name \NC name of the log file \NC \NR \NC banner \NC terminal display banner \NC \NR \NC var_used \NC variable (one|-|word) memory in use \NC \NR \NC dyn_used \NC token (multi|-|word) memory in use \NC \NR \NC str_ptr \NC number of strings \NC \NR \NC init_str_ptr \NC number of \INITEX\ strings \NC \NR \NC max_strings \NC maximum allowed strings \NC \NR \NC pool_ptr \NC string pool index \NC \NR \NC init_pool_ptr \NC \INITEX\ string pool index \NC \NR \NC pool_size \NC current size allocated for string characters \NC \NR \NC node_mem_usage \NC a string giving insight into currently used nodes \NC \NR \NC var_mem_max \NC number of allocated words for nodes \NC \NR \NC fix_mem_max \NC number of allocated words for tokens \NC \NR \NC fix_mem_end \NC maximum number of used tokens \NC \NR \NC cs_count \NC number of control sequences \NC \NR \NC hash_size \NC size of hash \NC \NR \NC hash_extra \NC extra allowed hash \NC \NR \NC font_ptr \NC number of active fonts \NC \NR \NC input_ptr \NC th elevel of input we're at \NC \NR \NC max_in_stack \NC max used input stack entries \NC \NR \NC max_nest_stack \NC max used nesting stack entries \NC \NR \NC max_param_stack \NC max used parameter stack entries \NC \NR \NC max_buf_stack \NC max used buffer position \NC \NR \NC max_save_stack \NC max used save stack entries \NC \NR \NC stack_size \NC input stack size \NC \NR \NC nest_size \NC nesting stack size \NC \NR \NC param_size \NC parameter stack size \NC \NR \NC buf_size \NC current allocated size of the line buffer \NC \NR \NC save_size \NC save stack size \NC \NR \NC obj_ptr \NC max \PDF\ object pointer \NC \NR \NC obj_tab_size \NC \PDF\ object table size \NC \NR \NC pdf_os_cntr \NC max \PDF\ object stream pointer \NC \NR \NC pdf_os_objidx \NC \PDF\ object stream index \NC \NR \NC pdf_dest_names_ptr \NC max \PDF\ destination pointer \NC \NR \NC dest_names_size \NC \PDF\ destination table size \NC \NR \NC pdf_mem_ptr \NC max \PDF\ memory used \NC \NR \NC pdf_mem_size \NC \PDF\ memory size \NC \NR \NC largest_used_mark \NC max referenced marks class \NC \NR \NC filename \NC name of the current input file \NC \NR \NC inputid \NC numeric id of the current input \NC \NR \NC linenumber \NC location in the current input file \NC \NR \NC lasterrorstring \NC last \TEX\ error string \NC \NR \NC lastluaerrorstring \NC last \LUA\ error string \NC \NR \NC lastwarningtag \NC last warning string\NC \NR \NC lastwarningstring \NC last warning tag, normally an indication of in what part\NC \NR \NC lasterrorcontext \NC last error context string (with newlines) \NC \NR \NC luabytecodes \NC number of active \LUA\ bytecode registers \NC \NR \NC luabytecode_bytes \NC number of bytes in \LUA\ bytecode registers \NC \NR \NC luastate_bytes \NC number of bytes in use by \LUA\ interpreters \NC \NR \NC output_active \NC \type {true} if the \type {\output} routine is active \NC \NR \NC callbacks \NC total number of executed callbacks so far \NC \NR \NC indirect_callbacks \NC number of those that were themselves a result of other callbacks (e.g. file readers) \NC \NR \NC luatex_version \NC the \LUATEX\ version number \NC \NR \NC luatex_revision \NC the \LUATEX\ revision string \NC \NR \NC ini_version \NC \type {true} if this is an \INITEX\ run \NC \NR \NC shell_escape \NC \type {0} means disabled, \type {1} is restricted and \type {2} means anything is permitted \NC \NR \stoptabulate The error and warning messages can be wiped with the \type {resetmessages} function. \section{The \type {tex} library} The \type {tex} table contains a large list of virtual internal \TEX\ parameters that are partially writable. The designation \quote {virtual} means that these items are not properly defined in \LUA, but are only front\-ends that are handled by a metatable that operates on the actual \TEX\ values. As a result, most of the \LUA\ table operators (like \type {pairs} and \type {#}) do not work on such items. At the moment, it is possible to access almost every parameter that has these characteristics: \startitemize[packed] \item You can use it after \type {\the} \item It is a single token. \item Some special others, see the list below \stopitemize This excludes parameters that need extra arguments, like \type {\the\scriptfont}. The subset comprising simple integer and dimension registers are writable as well as readable (stuff like \type {\tracingcommands} and \type {\parindent}). \subsection{Internal parameter values} For all the parameters in this section, it is possible to access them directly using their names as index in the \type {tex} table, or by using one of the functions \type {tex.get} and \type {tex.set}. If you created aliasses, you can use accessors like \type {tex.getdimen} as these also understand names of built|-|in variables. The exact parameters and return values differ depending on the actual parameter, and so does whether \type {tex.set} has any effect. For the parameters that {\it can\/} be set, it is possible to use \type {global} as the first argument to \type {tex.set}; this makes the assignment global instead of local. \startfunctioncall tex.set (["global",] n, ...) ... = tex.get ( n) \stopfunctioncall There are also dedicated setters, getters and checkers: \startfunctioncall local d = tex.getdimen("foo") if tex.isdimen("bar") then tex.setdimen("bar",d) end \stopfunctioncall There are such helpers for \type {dimen}, \type {count}, \type {skip}, \type {box} and \type {attribute} registers. \subsubsection{Integer parameters} The integer parameters accept and return \LUA\ numbers. Read|-|write: \starttwocolumns \starttyping tex.adjdemerits tex.binoppenalty tex.brokenpenalty tex.catcodetable tex.clubpenalty tex.day tex.defaulthyphenchar tex.defaultskewchar tex.delimiterfactor tex.displaywidowpenalty tex.doublehyphendemerits tex.endlinechar tex.errorcontextlines tex.escapechar tex.exhyphenpenalty tex.fam tex.finalhyphendemerits tex.floatingpenalty tex.globaldefs tex.hangafter tex.hbadness tex.holdinginserts tex.hyphenpenalty tex.interlinepenalty tex.language tex.lastlinefit tex.lefthyphenmin tex.linepenalty tex.localbrokenpenalty tex.localinterlinepenalty tex.looseness tex.mag tex.maxdeadcycles tex.month tex.newlinechar tex.outputpenalty tex.pausing tex.postdisplaypenalty tex.predisplaydirection tex.predisplaypenalty tex.pretolerance tex.relpenalty tex.righthyphenmin tex.savinghyphcodes tex.savingvdiscards tex.showboxbreadth tex.showboxdepth tex.time tex.tolerance tex.tracingassigns tex.tracingcommands tex.tracinggroups tex.tracingifs tex.tracinglostchars tex.tracingmacros tex.tracingnesting tex.tracingonline tex.tracingoutput tex.tracingpages tex.tracingparagraphs tex.tracingrestores tex.tracingscantokens tex.tracingstats tex.uchyph tex.vbadness tex.widowpenalty tex.year \stoptyping \stoptwocolumns Read|-|only: \startthreecolumns \starttyping tex.deadcycles tex.insertpenalties tex.parshape tex.prevgraf tex.spacefactor \stoptyping \stopthreecolumns \subsubsection{Dimension parameters} The dimension parameters accept \LUA\ numbers (signifying scaled points) or strings (with included dimension). The result is always a number in scaled points. Read|-|write: \startthreecolumns \starttyping tex.boxmaxdepth tex.delimitershortfall tex.displayindent tex.displaywidth tex.emergencystretch tex.hangindent tex.hfuzz tex.hoffset tex.hsize tex.lineskiplimit tex.mathsurround tex.maxdepth tex.nulldelimiterspace tex.overfullrule tex.pagebottomoffset tex.pageheight tex.pageleftoffset tex.pagerightoffset tex.pagetopoffset tex.pagewidth tex.parindent tex.predisplaysize tex.scriptspace tex.splitmaxdepth tex.vfuzz tex.voffset tex.vsize tex.prevdepth tex.prevgraf tex.spacefactor \stoptyping \stopthreecolumns Read|-|only: \startthreecolumns \starttyping tex.pagedepth tex.pagefilllstretch tex.pagefillstretch tex.pagefilstretch tex.pagegoal tex.pageshrink tex.pagestretch tex.pagetotal \stoptyping \stopthreecolumns Beware: as with all \LUA\ tables you can add values to them. So, the following is valid: \starttyping tex.foo = 123 \stoptyping When you access a \TEX\ parameter a look up takes place. For read||only variables that means that you will get something back, but when you set them you create a new entry in the table thereby making the original invisible. There are a few special cases that we make an exception for: \type {prevdepth}, \type {prevgraf} and \type {spacefactor}. These normally are accessed via the \type {tex.nest} table: \starttyping tex.nest[tex.nest.ptr].prevdepth = p tex.nest[tex.nest.ptr].spacefactor = s \stoptyping However, the following also works: \starttyping tex.prevdepth = p tex.spacefactor = s \stoptyping Keep in mind that when you mess with node lists directly at the \LUA\ end you might need to update the top of the nesting stack's \type {prevdepth} explicitly as there is no way \LUATEX\ can guess your intentions. By using the accessor in the \type {tex} tables, you get and set the values atthe top of the nest stack. \subsubsection{Direction parameters} The direction parameters are read|-|only and return a \LUA\ string. \startthreecolumns \starttyping tex.bodydir tex.mathdir tex.pagedir tex.pardir tex.textdir \stoptyping \stopthreecolumns \subsubsection{Glue parameters} The glue parameters accept and return a userdata object that represents a \type {glue_spec} node. \startthreecolumns \starttyping tex.abovedisplayshortskip tex.abovedisplayskip tex.baselineskip tex.belowdisplayshortskip tex.belowdisplayskip tex.leftskip tex.lineskip tex.parfillskip tex.parskip tex.rightskip tex.spaceskip tex.splittopskip tex.tabskip tex.topskip tex.xspaceskip \stoptyping \stopthreecolumns \subsubsection{Muglue parameters} All muglue parameters are to be used read|-|only and return a \LUA\ string. \startthreecolumns \starttyping tex.medmuskip tex.thickmuskip tex.thinmuskip \stoptyping \stopthreecolumns \subsubsection{Tokenlist parameters} The tokenlist parameters accept and return \LUA\ strings. \LUA\ strings are converted to and from token lists using \type {\the} \type {\toks} style expansion: all category codes are either space (10) or other (12). It follows that assigning to some of these, like \quote {tex.output}, is actually useless, but it feels bad to make exceptions in view of a coming extension that will accept full|-|blown token strings. \startthreecolumns \starttyping tex.errhelp tex.everycr tex.everydisplay tex.everyeof tex.everyhbox tex.everyjob tex.everymath tex.everypar tex.everyvbox tex.output tex.pdfpageattr tex.pdfpageresources tex.pdfpagesattr tex.pdfpkmode \stoptyping \stopthreecolumns \subsection{Convert commands} All \quote {convert} commands are read|-|only and return a \LUA\ string. The supported commands at this moment are: \starttwocolumns \starttyping tex.eTeXVersion tex.eTeXrevision tex.formatname tex.jobname tex.luatexbanner tex.luatexrevision tex.pdfnormaldeviate tex.fontname(number) tex.pdffontname(number) tex.pdffontobjnum(number) tex.pdffontsize(number) tex.uniformdeviate(number) tex.number(number) tex.romannumeral(number) tex.pdfpageref(number) tex.pdfxformname(number) tex.fontidentifier(number) \stoptyping \stoptwocolumns If you are wondering why this list looks haphazard; these are all the cases of the \quote {convert} internal command that do not require an argument, as well as the ones that require only a simple numeric value. The special (lua-only) case of \type {tex.fontidentifier} returns the \type {csname} string that matches a font id number (if there is one). if these are really needed in a macro package. \subsection{Last item commands} All \quote {last item} commands are read|-|only and return a number. The supported commands at this moment are: \startthreecolumns \starttyping tex.lastpenalty tex.lastkern tex.lastskip tex.lastnodetype tex.inputlineno tex.pdflastobj tex.pdflastxform tex.pdflastximage tex.pdflastximagepages tex.pdflastannot tex.pdflastxpos tex.pdflastypos tex.pdfrandomseed tex.pdflastlink tex.luatexversion tex.eTeXminorversion tex.eTeXversion tex.currentgrouplevel tex.currentgrouptype tex.currentiflevel tex.currentiftype tex.currentifbranch tex.pdflastximagecolordepth \stoptyping \stopthreecolumns \subsection{Attribute, count, dimension, skip and token registers} \TEX's attributes (\type {\attribute}), counters (\type {\count}), dimensions (\type {\dimen}), skips (\type {\skip}) and token (\type {\toks}) registers can be accessed and written to using two times five virtual sub|-|tables of the \type {tex} table: \startthreecolumns \starttyping tex.attribute tex.count tex.dimen tex.skip tex.toks \stoptyping \stopthreecolumns It is possible to use the names of relevant \type {\attributedef}, \type {\countdef}, \type {\dimendef}, \type {\skipdef}, or \type {\toksdef} control sequences as indices to these tables: \starttyping tex.count.scratchcounter = 0 enormous = tex.dimen['maxdimen'] \stoptyping In this case, \LUATEX\ looks up the value for you on the fly. You have to use a valid \type {\countdef} (or \type {\attributedef}, or \type {\dimendef}, or \type {\skipdef}, or \type {\toksdef}), anything else will generate an error (the intent is to eventually also allow \type {} and even macros that expand into a number). The attribute and count registers accept and return \LUA\ numbers. The dimension registers accept \LUA\ numbers (in scaled points) or strings (with an included absolute dimension; \type {em} and \type {ex} and \type {px} are forbidden). The result is always a number in scaled points. The token registers accept and return \LUA\ strings. \LUA\ strings are converted to and from token lists using \type {\the} \type {\toks} style expansion: all category codes are either space (10) or other (12). The skip registers accept and return \type {glue_spec} userdata node objects (see the description of the node interface elsewhere in this manual). As an alternative to array addressing, there are also accessor functions defined for all cases, for example, here is the set of possibilities for \type {\skip} registers: \startfunctioncall tex.setskip (["global",] n, s) tex.setskip (["global",] s, s) s = tex.getskip ( n) s = tex.getskip ( s) \stopfunctioncall We have similar setters for \type {count}, \type {dimen}, \type {muskip}, and \type {toks}. Counters and dimen are represented by numbers, skips and muskips by nodes, and toks by strings. For tokens registers we have an alternative where a catcode table is specified: \startfunctioncall tex.scantoks(0,3,"$e=mc^2$") tex.scantoks("global",0,"$\int\limits^1_2$") \stopfunctioncall In the function-based interface, it is possible to define values globally by using the string \type {global} as the first function argument. There are four extra skip related helpers: \startfunctioncall tex.setglue (["global"], n, width, stretch, shrink, stretch_order, shrink_order) tex.setglue (["global"], s, width, stretch, shrink, stretch_order, shrink_order) width, stretch, shrink, stretch_order, shrink_order = tex.getglue ( n) width, stretch, shrink, stretch_order, shrink_order = tex.getglue ( s) \stopfunctioncall The other two are \type {tex.setmuglue} and \type {tex.getmuglue}. \subsection{Character code registers} \TEX's character code tables (\type {\lccode}, \type {\uccode}, \type {\sfcode}, \type {\catcode}, \type {\mathcode}, \type {\delcode}) can be accessed and written to using six virtual subtables of the \type {tex} table \startthreecolumns \starttyping tex.lccode tex.uccode tex.sfcode tex.catcode tex.mathcode tex.delcode \stoptyping \stopthreecolumns The function call interfaces are roughly as above, but there are a few twists. \type {sfcode}s are the simple ones: \startfunctioncall tex.setsfcode (["global",] n, s) s = tex.getsfcode ( n) \stopfunctioncall The function call interface for \type {lccode} and \type {uccode} additionally allows you to set the associated sibling at the same time: \startfunctioncall tex.setlccode (["global"], n, lc) tex.setlccode (["global"], n, lc, uc) lc = tex.getlccode ( n) tex.setuccode (["global"], n, uc) tex.setuccode (["global"], n, uc, lc) uc = tex.getuccode ( n) \stopfunctioncall The function call interface for \type {catcode} also allows you to specify a category table to use on assignment or on query (default in both cases is the current one): \startfunctioncall tex.setcatcode (["global"], n, c) tex.setcatcode (["global"], cattable, n, c) lc = tex.getcatcode ( n) lc = tex.getcatcode ( cattable, n) \stopfunctioncall The interfaces for \type {delcode} and \type {mathcode} use small array tables to set and retrieve values: \startfunctioncall tex.setmathcode (["global"], n,
mval )
mval = tex.getmathcode ( n) tex.setdelcode (["global"], n,
dval )
dval = tex.getdelcode ( n) \stopfunctioncall Where the table for \type {mathcode} is an array of 3 numbers, like this: \starttyping { mathclass, family, character } \stoptyping And the table for \type {delcode} is an array with 4 numbers, like this: \starttyping { small_fam, small_char, large_fam, large_char } \stoptyping You can also avoid the table: \startfunctioncall class, family, char = tex.getmathcodes ( n) smallfam, smallchar, largefam, largechar = tex.getdelcodes ( n) \stopfunctioncall Normally, the third and fourth values in a delimiter code assignment will be zero according to \type {\Udelcode} usage, but the returned table can have values there (if the delimiter code was set using \type {\delcode}, for example). Unset \type {delcode}'s can be recognized because \type {dval[1]} is $-1$. \subsection{Box registers} It is possible to set and query actual boxes, using the node interface as defined in the \type {node} library: \starttyping tex.box \stoptyping for array access, or \starttyping tex.setbox(["global",] n, s) tex.setbox(["global",] cs, s) n = tex.getbox( n) n = tex.getbox( cs) \stoptyping for function|-|based access. In the function-based interface, it is possible to define values globally by using the string \type {global} as the first function argument. Be warned that an assignment like \starttyping tex.box[0] = tex.box[2] \stoptyping does not copy the node list, it just duplicates a node pointer. If \type {\box2} will be cleared by \TEX\ commands later on, the contents of \type {\box0} becomes invalid as well. To prevent this from happening, always use \type {node.copy_list()} unless you are assigning to a temporary variable: \starttyping tex.box[0] = node.copy_list(tex.box[2]) \stoptyping The following function will register a box for reuse (this is modelled after so called xforms in \PDF). You can (re)use the box with \type {\useboxresource} or by creating a rule node with subtype~2. \starttyping local index = tex.saveboxresource(n,attributes,resources,immediate) \stoptyping The optional second and third arguments are strings, the fourth is a boolean. You can generate the reference (a rule type) with: \starttyping local reused = tex.useboxresource(n,wd,ht,dp) \stoptyping The dimensions are optional and the final ones are returned as extra values. The following is just a bonus (no dimensions returned means that the resource is unknown): \starttyping local w, h, d = tex.getboxresourcedimensions(n) \stoptyping You can split a box: \starttyping local vlist = tex.splitbox(n,height,mode) \stoptyping The remainder is kept in the original box and a packaged vlist is returned. This operation is comparable to the \type {\vsplit} operation. The mode can be \type {additional} or \type {exactly} and concerns the split off box. \subsection{Math parameters} It is possible to set and query the internal math parameters using: \startfunctioncall tex.setmath(["global",] n, t, n) n = tex.getmath( n, t) \stopfunctioncall As before an optional first parameter \type {global} indicates a global assignment. The first string is the parameter name minus the leading \quote {Umath}, and the second string is the style name minus the trailing \quote {style}. Just to be complete, the values for the math parameter name are: \starttyping quad axis operatorsize overbarkern overbarrule overbarvgap underbarkern underbarrule underbarvgap radicalkern radicalrule radicalvgap radicaldegreebefore radicaldegreeafter radicaldegreeraise stackvgap stacknumup stackdenomdown fractionrule fractionnumvgap fractionnumup fractiondenomvgap fractiondenomdown fractiondelsize limitabovevgap limitabovebgap limitabovekern limitbelowvgap limitbelowbgap limitbelowkern underdelimitervgap underdelimiterbgap overdelimitervgap overdelimiterbgap subshiftdrop supshiftdrop subshiftdown subsupshiftdown subtopmax supshiftup supbottommin supsubbottommax subsupvgap spaceafterscript connectoroverlapmin ordordspacing ordopspacing ordbinspacing ordrelspacing ordopenspacing ordclosespacing ordpunctspacing ordinnerspacing opordspacing opopspacing opbinspacing oprelspacing opopenspacing opclosespacing oppunctspacing opinnerspacing binordspacing binopspacing binbinspacing binrelspacing binopenspacing binclosespacing binpunctspacing bininnerspacing relordspacing relopspacing relbinspacing relrelspacing relopenspacing relclosespacing relpunctspacing relinnerspacing openordspacing openopspacing openbinspacing openrelspacing openopenspacing openclosespacing openpunctspacing openinnerspacing closeordspacing closeopspacing closebinspacing closerelspacing closeopenspacing closeclosespacing closepunctspacing closeinnerspacing punctordspacing punctopspacing punctbinspacing punctrelspacing punctopenspacing punctclosespacing punctpunctspacing punctinnerspacing innerordspacing inneropspacing innerbinspacing innerrelspacing inneropenspacing innerclosespacing innerpunctspacing innerinnerspacing \stoptyping The values for the style parameter name are: \starttyping display crampeddisplay text crampedtext script crampedscript scriptscript crampedscriptscript \stoptyping The value is either a number (representing a dimension or number) or a glue spec node representing a muskip for \type {ordordspacing} and similar spacing parameters. \subsection{Special list heads} The virtual table \type {tex.lists} contains the set of internal registers that keep track of building page lists. \starttabulate[|lT|p|] \NC \bf field \NC \bf description \NC \NR \NC page_ins_head \NC circular list of pending insertions \NC \NR \NC contrib_head \NC the recent contributions \NC \NR \NC page_head \NC the current page content \NC \NR %NC temp_head \NC \NC \NR \NC hold_head \NC used for held-over items for next page \NC \NR \NC adjust_head \NC head of the current \type {\vadjust} list \NC \NR \NC pre_adjust_head \NC head of the current \type {\vadjust pre} list \NC \NR %NC align_head \NC \NC \NR \NC page_discards_head \NC head of the discarded items of a page break \NC \NR \NC split_discards_head \NC head of the discarded items in a vsplit \NC \NR \stoptabulate \subsection{Semantic nest levels} The virtual table \type {tex.nest} contains the currently active semantic nesting state. It has two main parts: a zero-based array of userdata for the semantic nest itself, and the numerical value \type {tex.nest.ptr}, which gives the highest available index. Neither the array items in \type {tex.nest[]} nor \type {tex.nest.ptr} can be assigned to (as this would confuse the typesetting engine beyond repair), but you can assign to the individual values inside the array items, e.g.\ \type {tex.nest[tex.nest.ptr].prevdepth}. \type {tex.nest[tex.nest.ptr]} is the current nest state, \type {tex.nest[0]} the outermost (main vertical list) level. The known fields are: \starttabulate[|lT|l|l|p|] \NC \rmbf key \NC \bf type \NC \bf modes \NC \bf explanation \NC \NR \NC mode \NC number \NC all \NC a number representing the main mode at this level: \type {0} = no mode (this happens during \type {\write}), \type {1} = vertical, \type {127} = horizontal, \type {253} = display math, \type {-1} = internal vertical, \type {-127} = restricted horizontal, \type {-253} = inline math \NC \NR \NC modeline \NC number \NC all \NC source input line where this mode was entered in, negative inside the output routine \NC \NR \NC head \NC node \NC all \NC the head of the current list \NC \NR \NC tail \NC node \NC all \NC the tail of the current list \NC \NR \NC prevgraf \NC number \NC vmode \NC number of lines in the previous paragraph \NC \NR \NC prevdepth \NC number \NC vmode \NC depth of the previous paragraph (equal to \type {\pdfignoreddimen} when it is to be ignored) \NC \NR \NC spacefactor \NC number \NC hmode \NC the current space factor \NC \NR \NC dirs \NC node \NC hmode \NC used for temporary storage by the line break algorithm\NC \NR \NC noad \NC node \NC mmode \NC used for temporary storage of a pending fraction numerator, for \type {\over} etc. \NC \NR \NC delimptr \NC node \NC mmode \NC used for temporary storage of the previous math delimiter, for \type {\middle} \NC \NR \NC mathdir \NC boolean \NC mmode \NC true when during math processing the \type {\mathdir} is not the same as the surrounding \type {\textdir} \NC \NR \NC mathstyle \NC number \NC mmode \NC the current \type {\mathstyle} \NC \NR \stoptabulate \subsection[sec:luaprint]{Print functions} The \type {tex} table also contains the three print functions that are the major interface from \LUA\ scripting to \TEX. The arguments to these three functions are all stored in an in|-|memory virtual file that is fed to the \TEX\ scanner as the result of the expansion of \type {\directlua}. The total amount of returnable text from a \type {\directlua} command is only limited by available system \RAM. However, each separate printed string has to fit completely in \TEX's input buffer. The result of using these functions from inside callbacks is undefined at the moment. \subsubsection{\type {tex.print}} \startfunctioncall tex.print( s, ...) tex.print( n, s, ...) tex.print(
t) tex.print( n,
t) \stopfunctioncall Each string argument is treated by \TEX\ as a separate input line. If there is a table argument instead of a list of strings, this has to be a consecutive array of strings to print (the first non-string value will stop the printing process). The optional parameter can be used to print the strings using the catcode regime defined by \type {\catcodetable}~\type {n}. If \type {n} is $-1$, the currently active catcode regime is used. If \type {n} is $-2$, the resulting catcodes are the result of \type {\the} \type {\toks}: all category codes are 12 (other) except for the space character, that has category code 10 (space). Otherwise, if \type {n} is not a valid catcode table, then it is ignored, and the currently active catcode regime is used instead. The very last string of the very last \type {tex.print()} command in a \type {\directlua} will not have the \type {\endlinechar} appended, all others do. \subsubsection{\type {tex.sprint}} \startfunctioncall tex.sprint( s, ...) tex.sprint( n, s, ...) tex.sprint(
t) tex.sprint( n,
t) \stopfunctioncall Each string argument is treated by \TEX\ as a special kind of input line that makes it suitable for use as a partial line input mechanism: \startitemize[packed] \startitem \TEX\ does not switch to the \quote {new line} state, so that leading spaces are not ignored. \stopitem \startitem No \type {\endlinechar} is inserted. \stopitem \startitem Trailing spaces are not removed. Note that this does not prevent \TEX\ itself from eating spaces as result of interpreting the line. For example, in \starttyping before\directlua{tex.sprint("\\relax")tex.sprint(" inbetween")}after \stoptyping the space before \type {in between} will be gobbled as a result of the \quote {normal} scanning of \type {\relax}. \stopitem \stopitemize If there is a table argument instead of a list of strings, this has to be a consecutive array of strings to print (the first non-string value will stop the printing process). The optional argument sets the catcode regime, as with \type {tex.print()}. \subsubsection{\type {tex.tprint}} \startfunctioncall tex.tprint({ n, s, ...}, {...}) \stopfunctioncall This function is basically a shortcut for repeated calls to \type {tex.sprint( n, s, ...)}, once for each of the supplied argument tables. \subsubsection{\type {tex.cprint}} This function takes a number indicating the to be used catcode, plus either a table of strings or an argument list of strings that will be pushed into the input stream. \startfunctioncall tex.cprint( 1," 1: $&{\\foo}") tex.print("\\par") -- a lot of \bgroup s tex.cprint( 2," 2: $&{\\foo}") tex.print("\\par") -- matching \egroup s tex.cprint( 9," 9: $&{\\foo}") tex.print("\\par") -- all get ignored tex.cprint(10,"10: $&{\\foo}") tex.print("\\par") -- all become spaces tex.cprint(11,"11: $&{\\foo}") tex.print("\\par") -- letters tex.cprint(12,"12: $&{\\foo}") tex.print("\\par") -- other characters tex.cprint(14,"12: $&{\\foo}") tex.print("\\par") -- comment triggers \stopfunctioncall \subsubsection{\type {tex.write}} \startfunctioncall tex.write( s, ...) tex.write(
t) \stopfunctioncall Each string argument is treated by \TEX\ as a special kind of input line that makes it suitable for use as a quick way to dump information: \startitemize \item All catcodes on that line are either \quote{space} (for '~') or \quote{character} (for all others). \item There is no \type {\endlinechar} appended. \stopitemize If there is a table argument instead of a list of strings, this has to be a consecutive array of strings to print (the first non-string value will stop the printing process). \subsection{Helper functions} \subsubsection{\type {tex.round}} \startfunctioncall n = tex.round( o) \stopfunctioncall Rounds \LUA\ number \type {o}, and returns a number that is in the range of a valid \TEX\ register value. If the number starts out of range, it generates a \quote {number to big} error as well. \subsubsection{\type {tex.scale}} \startfunctioncall n = tex.scale( o, delta)
n = tex.scale(table o, delta) \stopfunctioncall Multiplies the \LUA\ numbers \type {o} and \type {delta}, and returns a rounded number that is in the range of a valid \TEX\ register value. In the table version, it creates a copy of the table with all numeric top||level values scaled in that manner. If the multiplied number(s) are of range, it generates \quote{number to big} error(s) as well. Note: the precision of the output of this function will depend on your computer's architecture and operating system, so use with care! An interface to \LUATEX's internal, 100\% portable scale function will be added at a later date. \subsubsection{\type {tex.sp}} \startfunctioncall n = tex.sp( o) n = tex.sp( s) \stopfunctioncall Converts the number \type {o} or a string \type {s} that represents an explicit dimension into an integer number of scaled points. For parsing the string, the same scanning and conversion rules are used that \LUATEX\ would use if it was scanning a dimension specifier in its \TEX|-|like input language (this includes generating errors for bad values), expect for the following: \startitemize[n] \startitem only explicit values are allowed, control sequences are not handled \stopitem \startitem infinite dimension units (\type {fil...}) are forbidden \stopitem \startitem \type {mu} units do not generate an error (but may not be useful either) \stopitem \stopitemize \subsubsection{\type {tex.definefont}} \startfunctioncall tex.definefont( csname, fontid) tex.definefont( global, csname, fontid) \stopfunctioncall Associates \type {csname} with the internal font number \type {fontid}. The definition is global if (and only if) \type {global} is specified and true (the setting of \type {globaldefs} is not taken into account). \subsubsection{\type {tex.getlinenumber} and \type {tex.setlinenumber}} You can mess with the current line number: \startfunctioncall local n = tex.getlinenumber() tex.setlinenumber(n+10) \stopfunctioncall which can be shortcut to: \startfunctioncall tex.setlinenumber(10,true) \stopfunctioncall This might be handy when you have a callback that read numbers from a file and combines them in one line (in which case an error message probably has to refer to the original line). Interference with \TEX's internal handling of numbers is of course possible. \subsubsection{\type {tex.error}} \startfunctioncall tex.error( s) tex.error( s,
help) \stopfunctioncall This creates an error somewhat like the combination of \type {\errhelp} and \type {\errmessage} would. During this error, deletions are disabled. The array part of the \type {help} table has to contain strings, one for each line of error help. \subsubsection{\type {tex.hashtokens}} \startfunctioncall for i,v in pairs (tex.hashtokens()) do ... end \stopfunctioncall Returns a name and token table pair (see~\in {section} [luatokens] about token tables) iterator for every non-zero entry in the hash table. This can be useful for debugging, but note that this also reports control sequences that may be unreachable at this moment due to local redefinitions: it is strictly a dump of the hash table. \subsection[luaprimitives]{Functions for dealing with primitives } \subsubsection{\type {tex.enableprimitives}} \startfunctioncall tex.enableprimitives( prefix,
primitive names) \stopfunctioncall This function accepts a prefix string and an array of primitive names. For each combination of \quote {prefix} and \quote {name}, the \type {tex.enableprimitives} first verifies that \quote {name} is an actual primitive (it must be returned by one of the \type {tex.extraprimitives()} calls explained below, or part of \TEX82, or \type {\directlua}). If it is not, \type {tex.enableprimitives} does nothing and skips to the next pair. But if it is, then it will construct a csname variable by concatenating the \quote {prefix} and \quote {name}, unless the \quote {prefix} is already the actual prefix of \quote {name}. In the latter case, it will discard the \quote {prefix}, and just use \quote {name}. Then it will check for the existence of the constructed csname. If the csname is currently undefined (note: that is not the same as \type {\relax}), it will globally define the csname to have the meaning: run code belonging to the primitive \quote {name}. If for some reason the csname is already defined, it does nothing and tries the next pair. An example: \starttyping tex.enableprimitives('LuaTeX', {'formatname'}) \stoptyping will define \type {\LuaTeXformatname} with the same intrinsic meaning as the documented primitive \type {\formatname}, provided that the control sequences \type {\LuaTeXformatname} is currently undefined. When \LUATEX\ is run with \type {--ini} only the \TEX82 primitives and \type {\directlua} are available, so no extra primitives {\bf at all}. If you want to have all the new functionality available using their default names, as it is now, you will have to add \starttyping \ifx\directlua\undefined \else \directlua {tex.enableprimitives('',tex.extraprimitives ())} \fi \stoptyping near the beginning of your format generation file. Or you can choose different prefixes for different subsets, as you see fit. Calling some form of \type {tex.enableprimitives()} is highly important though, because if you do not, you will end up with a \TEX82-lookalike that can run \LUA\ code but not do much else. The defined csnames are (of course) saved in the format and will be available at runtime. \subsubsection{\type {tex.extraprimitives}} \startfunctioncall
t = tex.extraprimitives( s, ...) \stopfunctioncall This function returns a list of the primitives that originate from the engine(s) given by the requested string value(s). The possible values and their (current) return values are: \startluacode function document.showprimitives(tag) for k, v in table.sortedpairs(tex.extraprimitives(tag)) do if v == ' ' then v = '\\normalcontrolspace' end context.type(v) context.space() end end \stopluacode \starttabulate[|l|pl|] \NC \bf name\NC \bf values \NC \NR \NC tex \NC \ctxlua{document.showprimitives('tex') } \NC \NR \NC core \NC \ctxlua{document.showprimitives('core') } \NC \NR \NC etex \NC \ctxlua{document.showprimitives('etex') } \NC \NR \NC luatex \NC \ctxlua{document.showprimitives('luatex') } \NC \NR \stoptabulate Note that \type {'luatex'} does not contain \type {directlua}, as that is considered to be a core primitive, along with all the \TEX82 primitives, so it is part of the list that is returned from \type {'core'}. % \type {'umath'} is a subset of \type {'luatex'} that covers the Unicode math % primitives as it might be desired to handle the prefixing of that subset % differently. Running \type {tex.extraprimitives()} will give you the complete list of primitives \type {-ini} startup. It is exactly equivalent to \type {tex.extraprimitives('etex' and 'luatex')}. \subsubsection{\type {tex.primitives}} \startfunctioncall
t = tex.primitives() \stopfunctioncall This function returns a hash table listing all primitives that \LUATEX\ knows about. The keys in the hash are primitives names, the values are tables representing tokens (see~\in{section }[luatokens]). The third value is always zero. {\em In the beginning we had \type {omega} and \type {pdftex} subsets but in the meantime relevant primitives ave been promoted (either or not adapted) to the \type {luatex} set when found useful, or removed when considered to be of no use. Originally we had two sets of math definition primitives but the \OMEGA\ ones have been removed, so we no longer have a subset for math either.} \subsection{Core functionality interfaces} \subsubsection{\type {tex.badness}} \startfunctioncall b = tex.badness( t, s) \stopfunctioncall This helper function is useful during linebreak calculations. \type {t} and \type {s} are scaled values; the function returns the badness for when total \type {t} is supposed to be made from amounts that sum to \type {s}. The returned number is a reasonable approximation of $100(t/s)^3$; \subsubsection{\type {tex.resetparagraph}} This function resets the parameters that \TEX\ normally resets when a new paragraph is seen. \subsubsection{\type {tex.linebreak}} \startfunctioncall local nodelist,
info = tex.linebreak( listhead,
parameters) \stopfunctioncall The understood parameters are as follows: \starttabulate[|l|l|p|] \NC \bf name \NC \bf type \NC \bf description \NC \NR \NC pardir \NC string \NC \NC \NR \NC pretolerance \NC number \NC \NC \NR \NC tracingparagraphs \NC number \NC \NC \NR \NC tolerance \NC number \NC \NC \NR \NC looseness \NC number \NC \NC \NR \NC hyphenpenalty \NC number \NC \NC \NR \NC exhyphenpenalty \NC number \NC \NC \NR \NC pdfadjustspacing \NC number \NC \NC \NR \NC adjdemerits \NC number \NC \NC \NR \NC pdfprotrudechars \NC number \NC \NC \NR \NC linepenalty \NC number \NC \NC \NR \NC lastlinefit \NC number \NC \NC \NR \NC doublehyphendemerits \NC number \NC \NC \NR \NC finalhyphendemerits \NC number \NC \NC \NR \NC hangafter \NC number \NC \NC \NR \NC interlinepenalty \NC number or table \NC if a table, then it is an array like \type {\interlinepenalties} \NC \NR \NC clubpenalty \NC number or table \NC if a table, then it is an array like \type {\clubpenalties} \NC \NR \NC widowpenalty \NC number or table \NC if a table, then it is an array like \type {\widowpenalties} \NC \NR \NC brokenpenalty \NC number \NC \NC \NR \NC emergencystretch \NC number \NC in scaled points \NC \NR \NC hangindent \NC number \NC in scaled points \NC \NR \NC hsize \NC number \NC in scaled points \NC \NR \NC leftskip \NC glue_spec node \NC \NC \NR \NC rightskip \NC glue_spec node \NC \NC \NR \NC pdfignoreddimen \NC number \NC in scaled points \NC \NR \NC parshape \NC table \NC \NC \NR \stoptabulate Note that there is no interface for \type {\displaywidowpenalties}, you have to pass the right choice for \type {widowpenalties} yourself. The meaning of the various keys should be fairly obvious from the table (the names match the \TEX\ and \PDFTEX\ primitives) except for the last 5 entries. The four \type {pdf...line...} keys are ignored if their value equals \type {pdfignoreddimen}. It is your own job to make sure that \type {listhead} is a proper paragraph list: this function does not add any nodes to it. To be exact, if you want to replace the core line breaking, you may have to do the following (when you are not actually working in the \type {pre_linebreak_filter} or \type {linebreak_filter} callbacks, or when the original list starting at listhead was generated in horizontal mode): \startitemize \startitem add an \quote {indent box} and perhaps a \type {local_par} node at the start (only if you need them) \stopitem \startitem replace any found final glue by an infinite penalty (or add such a penalty, if the last node is not a glue) \stopitem \startitem add a glue node for the \type {\parfillskip} after that penalty node \stopitem \startitem make sure all the \type {prev} pointers are OK \stopitem \stopitemize The result is a node list, it still needs to be vpacked if you want to assign it to a \type {\vbox}. The returned \type {info} table contains four values that are all numbers: \starttabulate[|l|p|] \NC prevdepth \NC depth of the last line in the broken paragraph \NC \NR \NC prevgraf \NC number of lines in the broken paragraph \NC \NR \NC looseness \NC the actual looseness value in the broken paragraph \NC \NR \NC demerits \NC the total demerits of the chosen solution \NC \NR \stoptabulate Note there are a few things you cannot interface using this function: You cannot influence font expansion other than via \type {pdfadjustspacing}, because the settings for that take place elsewhere. The same is true for hbadness and hfuzz etc. All these are in the \type {hpack()} routine, and that fetches its own variables via globals. \subsubsection{\type {tex.shipout}} \startfunctioncall tex.shipout( n) \stopfunctioncall Ships out box number \type {n} to the output file, and clears the box register. \section[texconfig]{The \type {texconfig} table} This is a table that is created empty. A startup \LUA\ script could fill this table with a number of settings that are read out by the executable after loading and executing the startup file. \starttabulate[|lT|l|l|p|] \NC \rmbf key \NC \bf type \NC \bf default \NC \bf explanation \NC \NR \NC kpse_init \NC boolean \NC true \NC \type {false} totally disables \KPATHSEA\ initialisation, and enables interpretation of the following numeric key--value pairs. (only ever unset this if you implement {\it all\/} file find callbacks!) \NC \NR \NC shell_escape \NC string \NC \type {'f'} \NC Use \type {'y'} or \type {'t'} or \type {'1'} to enable \type {\write18} unconditionally, \type {'p'} to enable the commands that are listed in \type {shell_escape_commands} \NC \NR \NC shell_escape_commands \NC string \NC \NC Comma-separated list of command names that may be executed by \type {\write18} even if \type {shell_escape} is set to \type {'p'}. Do {\it not\/} use spaces around commas, separate any required command arguments by using a space, and use the \ASCII\ double quote (\type {"}) for any needed argument or path quoting \NC \NR \NC string_vacancies \NC number \NC 75000 \NC cf.\ web2c docs \NC \NR \NC pool_free \NC number \NC 5000 \NC cf.\ web2c docs \NC \NR \NC max_strings \NC number \NC 15000 \NC cf.\ web2c docs \NC \NR \NC strings_free \NC number \NC 100 \NC cf.\ web2c docs \NC \NR \NC nest_size \NC number \NC 50 \NC cf.\ web2c docs \NC \NR \NC max_in_open \NC number \NC 15 \NC cf.\ web2c docs \NC \NR \NC param_size \NC number \NC 60 \NC cf.\ web2c docs \NC \NR \NC save_size \NC number \NC 4000 \NC cf.\ web2c docs \NC \NR \NC stack_size \NC number \NC 300 \NC cf.\ web2c docs \NC \NR \NC dvi_buf_size \NC number \NC 16384 \NC cf.\ web2c docs \NC \NR \NC error_line \NC number \NC 79 \NC cf.\ web2c docs \NC \NR \NC half_error_line \NC number \NC 50 \NC cf.\ web2c docs \NC \NR \NC max_print_line \NC number \NC 79 \NC cf.\ web2c docs \NC \NR \NC hash_extra \NC number \NC 0 \NC cf.\ web2c docs \NC \NR \NC pk_dpi \NC number \NC 72 \NC cf.\ web2c docs \NC \NR \NC trace_file_names \NC boolean \NC true \NC \type {false} disables \TEX's normal file open|-|close feedback (the assumption is that callbacks will take care of that) \NC \NR \NC file_line_error \NC boolean \NC false \NC do \type {file:line} style error messages \NC \NR \NC halt_on_error \NC boolean \NC false \NC abort run on the first encountered error \NC \NR \NC formatname \NC string \NC \NC if no format name was given on the command line, this key will be tested first instead of simply quitting \NC \NR \NC jobname \NC string \NC \NC if no input file name was given on the command line, this key will be tested first instead of simply giving up \NC \NR \stoptabulate Note: the numeric values that match web2c parameters are only used if \type {kpse_init} is explicitly set to \type {false}. In all other cases, the normal values from \type {texmf.cnf} are used. \section{The \type {texio} library} This library takes care of the low|-|level I/O interface. \subsection{Printing functions} \subsubsection{\type {texio.write}} \startfunctioncall texio.write( target, s, ...) texio.write( s, ...) \stopfunctioncall Without the \type {target} argument, writes all given strings to the same location(s) \TEX\ writes messages to at this moment. If \type {\batchmode} is in effect, it writes only to the log, otherwise it writes to the log and the terminal. The optional \type {target} can be one of three possibilities: \type {term}, \type {log} or \type {term and log}. Note: If several strings are given, and if the first of these strings is or might be one of the targets above, the \type {target} must be specified explicitly to prevent \LUA\ from interpreting the first string as the target. \subsubsection{\type {texio.write_nl}} \startfunctioncall texio.write_nl( target, s, ...) texio.write_nl( s, ...) \stopfunctioncall This function behaves like \type {texio.write}, but make sure that the given strings will appear at the beginning of a new line. You can pass a single empty string if you only want to move to the next line. \subsubsection{\type {texio.setescape}} You can disable \type {^^} escaping of control characters by passing a value of zero. \section{The \type {token} libray} The current \type {token} library will be replaced by a new one that is more flexible and powerful. The transition takes place in steps. In version 0.80 we have \type {token} and in version 0.85 the old lib will be replaced completely. So if you use this new mechanism in production code you need to be aware of incompatible updates between 0.80 and 0.90. Because the related in- and output code will also be cleaned up and rewritten you should be aware of incompatible logging and error reporting too. The old library presents tokens as triplets or numbers, the new library presents a userdata object. The old library used a callback to intercept tokens in the input but the new library provides a basic scanner infrastructure that can be used to write macros that accept a wide range of arguments. This interface is on purpose kept general and as performance is quite ok one can build additional parsers without too much overhead. It's up to macro package writers to see how they can benefit from this as the main principle behind \LUATEX\ is to provide a minimal set of tools and no solutions. The current functions in the \type {token} namespace are given in the next table: \starttabulate[|lT|lT|p|] \NC \bf function \NC \bf argument \NC \bf result \NC \NR \HL \NC is_token \NC token \NC checks if the given argument is a token userdatum \NC \NR \NC get_next \NC \NC returns the next token in the input \NC \NR \NC scan_keyword \NC string \NC returns true if the given keyword is gobbled \NC \NR \NC scan_int \NC \NC returns a number \NC \NR \NC scan_dimen \NC infinity, mu-units \NC returns a number representing a dimension and or two numbers being the filler and order \NC \NR \NC scan_glue \NC mu-units \NC returns a glue spec node \NC \NR \NC scan_toks \NC definer, expand \NC returns a table of tokens token list (this can become a linked list in later releases) \NC \NR \NC scan_code \NC bitset \NC returns a character if its category is in the given bitset (representing catcodes) \NC \NR \NC scan_string \NC \NC returns a string given between \type {{}}, as \type {\macro} or as sequence of characters with catcode 11 or 12 \NC \NR \NC scan_word \NC \NC returns a sequence of characters with catcode 11 or 12 as string \NC \NR \NC scan_csname \NC \NC returns \type {foo} after scanning \type {\foo} \NC \NR \NC set_macro \NC see below \NC assign a macro \NC \NR \NC create \NC \NC returns a userdata token object of the given control sequence name (or character); this interface can change \NC \NR \stoptabulate The scanners can be considered stable apart from the one scanning for a token. This is because futures releases can return a linked list instead of a table (as with nodes). The \type {scan_code} function takes an optional number, the \type {keyword} function a normal \LUA\ string. The \type {infinity} boolean signals that we also permit \type {fill} as dimension and the \type {mu-units} flags the scanner that we expect math units. When scanning tokens we can indicate that we are defining a macro, in which case the result will also provide information about what arguments are expected and in the result this is separated from the meaning by a separator token. The \type {expand} flag determines if the list will be expanded. The string scanner scans for something between curly braces and expands on the way, or when it sees a control sequence it will return its meaning. Otherwise it will scan characters with catcode \type {letter} or \type {other}. So, given the following definition: \startbuffer \def\bar{bar} \def\foo{foo-\bar} \stopbuffer \typebuffer \getbuffer we get: \starttabulate[|l|Tl|l|] \NC \type {\directlua{token.scan_string()}{foo}} \NC \directlua{context("{\\red\\type {"..token.scan_string().."}}")} {foo} \NC full expansion \NR \NC \type {\directlua{token.scan_string()}foo} \NC \directlua{context("{\\red\\type {"..token.scan_string().."}}")} foo \NC letters and others \NR \NC \type {\directlua{token.scan_string()}\foo} \NC \directlua{context("{\\red\\type {"..token.scan_string().."}}")}\foo \NC meaning \NR \stoptabulate The \type {\foo} case only gives the meaning, but one can pass an already expanded definition (\type {\edef}'d). In the case of the braced variant one can of course use the \type {\detokenize} and \type {\unexpanded} primitives as there we do expand. The \type {scan_word} scanner can be used to implement for instance a number scanner: \starttyping function token.scan_number(base) return tonumber(token.scan_word(),base) end \stoptyping This scanner accepts any valid \LUA\ number so it is a way to pick up floats in the input. The creator function can be used as follows: \starttyping local t = token.create("relax") \stoptyping This gives back a token object that has the properties of the \type {\relax} primitive. The possible properties of tokens are: \starttabulate[|lT|p|] \NC command \NC a number representing the internal command number \NC \NR \NC cmdname \NC the type of the command (for instance the catcode in case of a character or the classifier that determines the internal treatment \NC \NR \NC csname \NC the associated control sequence (if applicable) \NC \NR \NC id \NC the unique id of the token \NC \NR %NC tok \NC \NC \NR % might change \NC active \NC a boolean indicating the active state of the token \NC \NR \NC expandable \NC a boolean indicating if the token (macro) is expandable \NC \NR \NC protected \NC a boolean indicating if the token (macro) is protected \NC \NR \stoptabulate The numbers that represent a catcode are the same as in \TEX\ itself, so using this information assumes that you know a bit about \TEX's internals. The other numbers and names are used consistently but are not frozen. So, when you use them for comparing you can best query a known primitive or character first to see the values. More interesting are the scanners. You can use the \LUA\ interface as follows: \starttyping \directlua { function mymacro(n) ... end } \def\mymacro#1{% \directlua { mymacro(\number\dimexpr#1) }% } \mymacro{12pt} \mymacro{\dimen0} \stoptyping You can also do this: \starttyping \directlua { function mymacro() local d = token.scan_dimen() ... end } \def\mymacro{% \directlua { mymacro() }% } \mymacro 12pt \mymacro \dimen0 \stoptyping It is quite clear from looking at the code what the first method needs as argument(s). For the second method you need to look at the \LUA\ code to see what gets picked up. Instead of passing from \TEX\ to \LUA\ we let \LUA\ fetch from the input stream. In the first case the input is tokenized and then turned into a string when it's passed to \LUA\ where it gets interpreted. In the second case only a function call gets interpreted but then the input is picked up by explicitly calling the scanner functions. These return proper \LUA\ variables so no further conversion has to be done. This is more efficient but in practice (given what \TEX\ has to do) this effect should not be overestimated. For numbers and dimensions it saves a bit but for passing strings conversion to and from tokens has to be done anyway (although we can probably speed up the process in later versions if needed). When the interface is stable and has replaced the old one completely we will add some more information here. By that time the internals have been cleaned up a bit more so we know then what will stay and go. A positive side effect of this transition is that we can simplify the input part because we no longer need to intercept using callbacks. The \type {set_macro} function can get upto 4 arguments: \starttyping setmacro("csname","content") setmacro("csname","content","global") setmacro("csname") \stoptyping You can pass a catcodetable identifier as first argument: \starttyping setmacro(catcodetable,"csname","content") setmacro(catcodetable,"csname","content","global") setmacro(catcodetable,"csname") \stoptyping The results are like: \starttyping \def\csname{content} \gdef\csname{content} \def\csname{} \stoptyping There is a (for now) experimental putter: \starttyping local t1 = token.get_next() local t2 = token.get_next() local t3 = token.get_next() local t4 = token.get_next() -- watch out, we flush in sequence token.put_next { t1, t2 } -- but this one gets pushed in front token.put_next ( t3, t4 ) \stoptyping When we scan \type {wxyz!} we get \type {yzwx!} back. The argument is either a table with tokens or a list of tokens. \section{The \type {kpse} library} This library provides two separate, but nearly identical interfaces to the \KPATHSEA\ file search functionality: there is a \quote {normal} procedural interface that shares its kpathsea instance with \LUATEX\ itself, and an object oriented interface that is completely on its own. \subsection{\type {kpse.set_program_name} and \type {kpse.new}} Before the search library can be used at all, its database has to be initialized. There are three possibilities, two of which belong to the procedural interface. First, when \LUATEX\ is used to typeset documents, this initialization happens automatically and the \KPATHSEA\ executable and program names are set to \type {luatex} (that is, unless explicitly prohibited by the user's startup script. See~\in {section} [init] for more details). Second, in \TEXLUA\ mode, the initialization has to be done explicitly via the \type {kpse.set_program_name} function, which sets the \KPATHSEA\ executable (and optionally program) name. \startfunctioncall kpse.set_program_name( name) kpse.set_program_name( name, progname) \stopfunctioncall The second argument controls the use of the \quote {dotted} values in the \type {texmf.cnf} configuration file, and defaults to the first argument. Third, if you prefer the object oriented interface, you have to call a different function. It has the same arguments, but it returns a userdata variable. \startfunctioncall local kpathsea = kpse.new( name) local kpathsea = kpse.new( name, progname) \stopfunctioncall Apart from these two functions, the calling conventions of the interfaces are identical. Depending on the chosen interface, you either call \type {kpse.find_file()} or \type {kpathsea:find_file()}, with identical arguments and return vales. \subsection{\type {find_file}} The most often used function in the library is \type {find_file}: \startfunctioncall f = kpse.find_file( filename) f = kpse.find_file( filename, ftype) f = kpse.find_file( filename, mustexist) f = kpse.find_file( filename, ftype, mustexist) f = kpse.find_file( filename, ftype, dpi) \stopfunctioncall Arguments: \startitemize[intro] \sym{filename} the name of the file you want to find, with or without extension. \sym{ftype} maps to the \type {-format} argument of \KPSEWHICH. The supported \type {ftype} values are the same as the ones supported by the standalone \type {kpsewhich} program: \startluacode local list = { "afm", "base", "bib", "bitmap font", "bst", "cid maps", "clua", "cmap files", "cnf", "cweb", "dvips config", "enc files", "fmt", "font feature files", "gf", "graphic|/|figure", "ist", "lig files", "ls-R", "lua", "map", "mem", "MetaPost support", "mf", "mfpool", "mft", "misc fonts", "mlbib", "mlbst", "mp", "mppool", "ocp", "ofm", "opentype fonts", "opl", "other binary files", "other text files", "otp", "ovf", "ovp", "pdftex config", "pk", "PostScript header", "subfont definition files", "tex", "TeX system documentation", "TeX system sources", "texmfscripts", "texpool", "tfm", "Troff fonts", "truetype fonts", "type1 fonts", "type42 fonts", "vf", "web", "web2c files", } table.sort(list) context("{\\tttf \letterpercent, t}",list) \stopluacode The default type is \type {tex}. Note: this is different from \KPSEWHICH, which tries to deduce the file type itself from looking at the supplied extension. \sym{mustexist} is similar to \KPSEWHICH's \type {-must-exist}, and the default is \type {false}. If you specify \type {true} (or a non|-|zero integer), then the \KPSE\ library will search the disk as well as the \type {ls-R} databases. \sym{dpi} This is used for the size argument of the formats \type {pk}, \type {gf}, and \type {bitmap font}. \stopitemize \subsection{\type {lookup}} A more powerful (but slower) generic method for finding files is also available. It returns a string for each found file. \startfunctioncall f, ... = kpse.lookup( filename,
options) \stopfunctioncall The options match commandline arguments from \type {kpsewhich}: \starttabulate[|l|l|p|] \NC \rmbf key \NC \rmbf type \NC \rmbf description \NC \NR \NC debug \NC number \NC set debugging flags for this lookup\NC \NR \NC format \NC string \NC use specific file type (see list above)\NC \NR \NC dpi \NC number \NC use this resolution for this lookup; default 600\NC \NR \NC path \NC string \NC search in the given path\NC \NR \NC all \NC boolean \NC output all matches, not just the first\NC \NR \NC mustexist \NC boolean \NC search the disk as well as ls-R if necessary\NC \NR \NC mktexpk \NC boolean \NC disable/enable mktexpk generation for this lookup\NC \NR \NC mktextex \NC boolean \NC disable/enable mktextex generation for this lookup\NC \NR \NC mktexmf \NC boolean \NC disable/enable mktexmf generation for this lookup\NC \NR \NC mktextfm \NC boolean \NC disable/enable mktextfm generation for this lookup\NC \NR \NC subdir \NC string or table \NC only output matches whose directory part ends with the given string(s) \NC \NR \stoptabulate \subsection{\type {init_prog}} Extra initialization for programs that need to generate bitmap fonts. \startfunctioncall kpse.init_prog( prefix, base_dpi, mfmode) kpse.init_prog( prefix, base_dpi, mfmode, fallback) \stopfunctioncall \subsection{\type {readable_file}} Test if an (absolute) file name is a readable file. \startfunctioncall f = kpse.readable_file( name) \stopfunctioncall The return value is the actual absolute filename you should use, because the disk name is not always the same as the requested name, due to aliases and system|-|specific handling under e.g.\ \MSDOS. Returns \type {nil} if the file does not exist or is not readable. \subsection{\type {expand_path}} Like kpsewhich's \type {-expand-path}: \startfunctioncall r = kpse.expand_path( s) \stopfunctioncall \subsection{\type {expand_var}} Like kpsewhich's \type {-expand-var}: \startfunctioncall r = kpse.expand_var( s) \stopfunctioncall \subsection{\type {expand_braces}} Like kpsewhich's \type {-expand-braces}: \startfunctioncall r = kpse.expand_braces( s) \stopfunctioncall \subsection{\type {show_path}} Like kpsewhich's \type {-show-path}: \startfunctioncall r = kpse.show_path( ftype) \stopfunctioncall \subsection{\type {var_value}} Like kpsewhich's \type {-var-value}: \startfunctioncall r = kpse.var_value( s) \stopfunctioncall \subsection{\type {version}} Returns the kpathsea version string. \startfunctioncall r = kpse.version() \stopfunctioncall \stopchapter \stopcomponent