\usemodule[present-boring,abbreviations-logos] \startdocument [title={DATATYPES}, banner={additional datatypes in lmtx}, location={context\enspace {\bf 2020}\enspace meeting}] \starttitle[title=Native \TEX\ datatypes: simple registers] \startbuffer integer: \count 123 = 456 \the\count123 \stopbuffer \typebuffer {\getbuffer} \startbuffer dimension: \dimen123 = 456pt \the\dimen123 \stopbuffer \typebuffer {\getbuffer} \startbuffer glue: \skip123 = 6pt plus 5pt minus 4pt\relax \the\skip123 \stopbuffer \typebuffer {\getbuffer} \startbuffer muglue: \muskip123 = 6mu plus 5mu minus 4mu\relax \the\muskip123 \stopbuffer \typebuffer {\getbuffer} \startbuffer attribute: \attribute123 = 456 \the\attribute123 \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping \global \the \countdef \dimendef \skipdef \muskipdef \attributedef \advance \multiply \divide \numexpr \dimexpr \glueexpr \muexpr \stoptyping \stoptitle \starttitle[title=Native \TEX\ datatypes: tokens] \startbuffer toks: \toks123 = {456} \the\toks123 \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping \global \the \toksdef \toksapp \etoksapp \xtoksapp \gtoksapp \tokspre \etokspre \xtokspre \gtokspre \stoptyping \blank[2*line] (in retrospect: eetex) \stoptitle \starttitle[title=Native \TEX\ datatypes: boxes] \startbuffer box: \box123 = \hbox {456} (\the\wd123,\the\ht123,\the\dp123) \box123 \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping \global \box \copy \unhbox \unvbox \hbox \vbox \vtop \hpack \vpack \tpack \wd \ht \dp \boxtotal \boxdirection \boxattr \boxorientation \boxxoffset \boxyoffset \boxxmove \boxymove \stoptyping \stoptitle \starttitle[title=Native \TEX\ datatypes: macros] \startbuffer \def\onetwothree{346} \onetwothree \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping \global \protected \frozen \def \edef \edef \xdef \meaning \stoptyping \stoptitle \starttitle[title=Native \LUA\ datatypes: numbers] \startbuffer \ctxlua{local n = 123 context(n)}\quad \ctxlua{local n = 123.456 context(n)}\quad \ctxlua{local n = 123.4E56 context(n)}\quad \ctxlua{local n = 0x123 context(n)}\quad \ctxlua{local n = 0x1.37fe4cd4b70b2p-1 context(n)} \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping + - * / // % ^ | ~ & << >> == ~= < > <= >= ( ) \stoptyping \stoptitle \starttitle[title=Native \LUA\ datatypes: strings] \startbuffer \ctxlua{local s = "abc" context(s)}\quad \ctxlua{local s = 'abc' context(s)}\quad \ctxlua{local s = [[abc]] context(s)}\quad \ctxlua{local s = [==[abc]==] context(s)}\quad \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping .. # == ~= < > <= >= \stoptyping \stoptitle \starttitle[title=Native \LUA\ datatypes: booleans and nil] \startbuffer \ctxlua{local b = true context(b)}\quad \ctxlua{local b = false context(b)}\quad \ctxlua{local n = nil context(n)}\quad \stopbuffer \typebuffer {\getbuffer} \blank[2*line] \starttyping == ~= and or not \stoptyping \stoptitle \starttitle[title=Native \LUA\ datatypes: some more] \starttyping functions userdata (lpeg is userdata) coroutine \stoptyping \LUAMETATEX\ provides tokens and nodes as userdata and some libraries also use them (complex, decimal, pdf, etc). \stoptitle \starttitle[title=Both worlds combined] \startitemize[packed] \startitem There are only 64K registers (although we can extend that if needed). \stopitem \startitem Accessing registers at the \LUA\ end is not that efficient. \stopitem \startitem So we have now datatypes at the \LUA\ end with access at the \TEX\ end. \stopitem \startitem Their values can go beyond what \TEX\ registers provide. \stopitem \stopitemize \startbuffer \luacardinal bar 123 \luainteger bar -456 \luafloat bar 123.456E-3 \stopbuffer \typebuffer \getbuffer \startbuffer \the\luacardinal bar \quad \the\luainteger bar \quad \the\luafloat bar \stopbuffer \typebuffer \getbuffer \page The usual \LUA\ semantics apply: \startbuffer \luacardinal bar 0x123 \luainteger bar -0x456 \luafloat bar 0x123.456p-3 \stopbuffer \typebuffer \getbuffer So, now we get: \startbuffer \the\luacardinal bar \quad \the\luainteger bar \quad \the\luafloat bar \stopbuffer \getbuffer Equal signs are optional: \startbuffer \luainteger gnu= 123456 \luafloat gnu= 123.456e12 \luainteger gnu = 123456 \luafloat gnu = 123.456e12 \luainteger gnu =123456 \luafloat gnu =123.456e12 \stopbuffer \typebuffer These commands can be uses for assignments as well as serialization. They use the \LUAMETATEX\ value function feature. \page Dimensions are serialized differently so that they can be used like this: \startbuffer \luadimen test 100pt \scratchdimen = .25 \luadimen test: \the\scratchdimen \stopbuffer \typebuffer \getbuffer \page Assume that we have this: \startbuffer \luacardinal x = -123 \luafloat x = 123.123 \luacardinal y = 456 \luafloat y = -456.456 \stopbuffer \typebuffer \getbuffer We can then use the macro \type {\luaexpression} that takes an optional keyword: \startbuffer - : \luaexpression {n.x + 2*n.y} f : \luaexpression float {n.x + 2*n.y} i : \luaexpression integer {n.x + 2*n.y} c : \luaexpression cardinal {n.x + 2*n.y} b : \luaexpression boolean {n.x + 2*n.y} l : \luaexpression lua {n.x + 2*n.y} \stopbuffer \typebuffer The serialization can be different for these cases: \startlines \tt \getbuffer \stoplines Variables have their own namespace but get resolved across namespaces (f, i, c). \page Special tricks: \startbuffer \scratchdimen 123.456pt [\the\scratchdimen] [\the\nodimen\scratchdimen] \stopbuffer \typebuffer \getbuffer Does nothing, nor does: \startbuffer \nodimen\scratchdimen = 654.321pt \stopbuffer \typebuffer \getbuffer But: \starttabulate[|T|T|] \NC \type {\the\nodimen bp \scratchdimen} \NC \the\nodimen bp \scratchdimen \NC \NR \NC \type {\the\nodimen cc \scratchdimen} \NC \the\nodimen cc \scratchdimen \NC \NR \NC \type {\the\nodimen cm \scratchdimen} \NC \the\nodimen cm \scratchdimen \NC \NR \NC \type {\the\nodimen dd \scratchdimen} \NC \the\nodimen dd \scratchdimen \NC \NR \NC \type {\the\nodimen in \scratchdimen} \NC \the\nodimen in \scratchdimen \NC \NR \NC \type {\the\nodimen mm \scratchdimen} \NC \the\nodimen mm \scratchdimen \NC \NR \NC \type {\the\nodimen pt \scratchdimen} \NC \the\nodimen pt \scratchdimen \NC \NR \NC \type {\the\nodimen sp \scratchdimen} \NC \the\nodimen sp \scratchdimen \NC \NR \stoptabulate gives different units! In the coffee break it was decided to drop the \type {nc} and \type {nd} units in \LUAMETATEX\ when Arthur indicated that they never became a standard. Dropping the \type {true} variants also makes sense but we postponed dropping the \type {in} (inch). \stoptitle \starttitle[title=Arrays] Two dimensional arrays have names and a type: \startbuffer \newarray name integers type integer nx 2 ny 2 \newarray name booleans type boolean nx 2 ny 2 \newarray name floats type float nx 2 ny 2 \newarray name dimensions type dimension nx 4 \stopbuffer \typebuffer \getbuffer And a special accessor. Here we set values: \startbuffer \arrayvalue integers 1 2 4 \arrayvalue integers 2 1 8 \arrayvalue booleans 1 2 true \arrayvalue booleans 2 1 true \arrayvalue floats 1 2 12.34 \arrayvalue floats 2 1 34.12 \arrayvalue dimensions 1 12.34pt \arrayvalue dimensions 3 34.12pt \stopbuffer \typebuffer \getbuffer \page Here we get values: \startbuffer [\the\arrayvalue integers 1 2] [\the\arrayvalue booleans 1 2] [\the\arrayvalue floats 1 2] [\the\arrayvalue dimensions 1 ]\crlf [\the\arrayvalue integers 2 1] [\the\arrayvalue booleans 2 1] [\the\arrayvalue floats 2 1] [\the\arrayvalue dimensions 3] \stopbuffer \typebuffer \getbuffer When a value is expected the integer is serialized: \startbuffer \scratchcounter\arrayvalue integers 1 2\relax \the\scratchcounter \stopbuffer \typebuffer \getbuffer You can view an array on the console with: \starttyping \showarray integers \stoptyping \page Another expression example: \startbuffer \dostepwiserecurse {1} {4} {1} { [\the\arrayvalue dimensions #1 : \luaexpression dimen {math.sind(30) * a.dimensions[#1]}] } \stopbuffer \typebuffer \getbuffer \page We can combine it all with if tests: \startbuffer slot 1 is \ifboolean\arrayequals dimensions 1 0pt zero \else not zero \fi\quad slot 2 is \ifboolean\arrayequals dimensions 2 0pt zero \else not zero \fi \stopbuffer \typebuffer \getbuffer \startbuffer slot 1: \ifcase\arraycompare dimensions 1 3pt lt \or eq \else gt \fi zero\quad slot 2: \ifcase\arraycompare dimensions 2 3pt lt \or eq \else gt \fi zero\quad slot 3: \ifcase\arraycompare dimensions 3 3pt lt \or eq \else gt \fi zero\quad slot 4: \ifcase\arraycompare dimensions 4 3pt lt \or eq \else gt \fi zero slot 1: \ifcmpdim\arrayvalue dimensions 1 3pt lt \or eq \else gt \fi zero\quad slot 2: \ifcmpdim\arrayvalue dimensions 2 3pt lt \or eq \else gt \fi zero\quad slot 3: \ifcmpdim\arrayvalue dimensions 3 3pt lt \or eq \else gt \fi zero\quad slot 4: \ifcmpdim\arrayvalue dimensions 4 3pt lt \or eq \else gt \fi zero \stopbuffer \typebuffer \getbuffer \stoptitle \starttitle[title=Complex numbers] \startbuffer \startluacode local c1 = xcomplex.new(1,3) local c2 = xcomplex.new(2,4) context(c1) context.quad() context(c2) context.quad(c1 + c2) \stopluacode \stopbuffer \typebuffer \getbuffer \stoptitle \starttitle[title=Decimal numbers] \startbuffer \startluacode local c1 = xdecimal.new("123456789012345678901234567890") local c2 = xdecimal.new(1234567890) context(c1) context.crlf() context(c2) context.crlf(c1 * c2) \stopluacode \stopbuffer \typebuffer \getbuffer \stoptitle \stopdocument