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diff --git a/doc/context/sources/general/manuals/luatex/luatex-languages.tex b/doc/context/sources/general/manuals/luatex/luatex-languages.tex index 19e3f7b14..54a7b390d 100644 --- a/doc/context/sources/general/manuals/luatex/luatex-languages.tex +++ b/doc/context/sources/general/manuals/luatex/luatex-languages.tex @@ -147,6 +147,38 @@ hyphenation happens is (normally) when the paragraph or a horizontal box is constructed. When \type {\savinghyphcodes} was zero when the language got initialized you start out with nothing, otherwise you already have a set. +When a \type {\hjcode} is larger than $0$ but smaller than $32$ is indicates the +to be used length. In the following example we map a character (\type {x}) onto +another one in the patterns and tell the engine that \type {œ} counts as one +character. Because traditionally zero itself is reserved for inhibiting +hyphenation, a value of $32$ counts as zero. + +\starttyping +% assuming french patterns: +foobar % foo-bar + +\hjcode`x=`o + +fxxbar % fxx-bar + +\lefthyphenmin3 + +œdipus % œdi-pus + +\lefthyphenmin4 + +œdipus % œdipus + +\hjcode`œ=2 + +œdipus % œdi-pus + +\hjcode`i=32 +\hjcode`d=32 + +œdipus % œdipus +\stoptyping + Carrying all this information with each glyph would give too much overhead and also make the process of setting up thee codes more complex. A solution with \type {hjcode} sets was considered but rejected because in practice the current @@ -180,6 +212,134 @@ as trigger. Here are a few examples of usage: \stopbuffer \typebuffer \start \dontcomplain \hsize 1pt \getbuffer \par \stop +We only accept an explicit hyphen when there is a preceding glyph and we skip a +sequence of explicit hyphens as that normally indicates a \type {--} or \type +{---} ligature in which case we can in a worse case usage get bad node lists +later on due to messed up ligature building as these dashes are ligatures in base +fonts. This is a side effect of the separating the hyphenation, ligaturing and +kerning steps. + +The start and end of a characters is signalled by a glue, penalty, kern or boundary +node. But by default also a hlist, vlist, rule, dir, whatsit, ins, and adjust node +indicate a start or end. You can omit the last set from the test by setting +\type {\hyphenationbounds} to a non|-|zero value: + +\starttabulate[|Tl|l|] +\NC 0 \NC not strict \NC \NR +\NC 1 \NC strict start \NC \NR +\NC 2 \NC strict end \NC \NR +\NC 3 \NC strict start and strict end \NC \NR +\stoptabulate + +The word start is determined as follows: + +\starttabulate[|Bl|l|] +\NC boundary \NC yes when wordboundary \NC \NR +\NC hlist \NC when hyphenationbounds 1 or 3 \NC \NR +\NC vlist \NC when hyphenationbounds 1 or 3 \NC \NR +\NC rule \NC when hyphenationbounds 1 or 3 \NC \NR +\NC dir \NC when hyphenationbounds 1 or 3 \NC \NR +\NC whatsit \NC when hyphenationbounds 1 or 3 \NC \NR +\NC glue \NC yes \NC \NR +\NC math \NC skipped \NC \NR +\NC glyph \NC exhyphenchar (one only) : yes (so no -- ---) \NC \NR +\NC otherwise \NC yes \NC \NR +\stoptabulate + +The word end is determined as follows: + +\starttabulate[|Bl|l|] +\NC boundary \NC yes \NC \NR +\NC glyph \NC yes when different language \NC \NR +\NC glue \NC yes \NC \NR +\NC penalty \NC yes \NC \NR +\NC kern \NC yes when not italic (for some historic reason) \NC \NR +\NC hlist \NC when hyphenationbounds 2 or 3 \NC \NR +\NC vlist \NC when hyphenationbounds 2 or 3 \NC \NR +\NC rule \NC when hyphenationbounds 2 or 3 \NC \NR +\NC dir \NC when hyphenationbounds 2 or 3 \NC \NR +\NC whatsit \NC when hyphenationbounds 2 or 3 \NC \NR +\NC ins \NC when hyphenationbounds 2 or 3 \NC \NR +\NC adjust \NC when hyphenationbounds 2 or 3 \NC \NR +\stoptabulate + +% (Future versions of \LUATEX\ might provide more granularity.) + +In traditional \TEX\ ligature building and hyphenation are interwoven with the +line break mechanism. In \LUATEX\ these phases are isolated. As a consequence we +deal differently with (a sequence of) explicit hyphens. We already have added +some control over aspects of the hyphenation and yet another one concerns +automatic hyphens (e.g.\ \type {-} characters in the input). + +When \type {\automatichyphenmode} has a value of 0, a hyphen will be turned into +an automatic discretionary. The snippets before and after it will not be +hyphenated. A side effect is that a leading hyphen can lead to a split but one +will seldom run into that situation. Setting a pre and post character makes this +more prominent. A value of 1 will prevent this side effect and a value of 2 will +not turn the hyphen into a discretionary. Experiments with other options, like +permitting hyphenation, of the words on both sides were discarded. + +\startbuffer[a] +before-after \par +before--after \par +before---after \par +\stopbuffer + +\startbuffer[b] +-before \par +after- \par +--before \par +after-- \par +---before \par +after--- \par +\stopbuffer + +\startbuffer[c] +before-after \par +before--after \par +before---after \par +\stopbuffer + +We show three samples: + +Input A: \typebuffer[a] +Input B: \typebuffer[b] +Input C: \typebuffer[c] + +\startbuffer[demo] +\startcombination[nx=4,ny=3,location=top] + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize6em \getbuffer[a]}} {A~0~6em} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize2pt \getbuffer[a]}} {A~0~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plusone \hsize2pt \getbuffer[a]}} {A~1~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plustwo \hsize2pt \getbuffer[a]}} {A~2~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize6em \getbuffer[b]}} {B~0~6em} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize2pt \getbuffer[b]}} {B~0~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plusone \hsize2pt \getbuffer[b]}} {B~1~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plustwo \hsize2pt \getbuffer[b]}} {B~2~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize6em \getbuffer[c]}} {C~0~6em} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\zerocount \hsize2pt \getbuffer[c]}} {C~0~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plusone \hsize2pt \getbuffer[c]}} {C~1~2pt} + {\framed[align=normal,strut=no,top=\vskip.5ex,bottom=\vskip.5ex]{\automatichyphenmode\plustwo \hsize2pt \getbuffer[c]}} {C~2~2pt} +\stopcombination +\stopbuffer + +\startplacefigure[reference=automatic:1,title={The automatic modes \type {0} (default), \type {1} and \type {2}, with a \type {\hsize} +of 6em and 2pt (which triggers a linebreak).}] + \dontcomplain \tt \getbuffer[demo] +\stopplacefigure + +\startplacefigure[reference=automatic:2,title={The automatic modes \type {0} (default), \type {1} and \type {2}, with \type +{\preexhyphenchar} and \type {\postexhyphenchar} set to characters \type {A} and \type {B}.}] + \postexhyphenchar`A\relax + \preexhyphenchar `B\relax + \dontcomplain \tt \getbuffer[demo] +\stopplacefigure + +As with primitive companions of other single character commands, the \type {\-} +command has a more verbose primitive version in \type {\explicitdiscretionary} +and the normally intercepted in the hyphenator character \type {-} (or whatever +is configured) is available as \type {\automaticdiscretionary}. + \section{The main control loop} In \LUATEX's main loop, almost all input characters that are to be typeset are @@ -260,6 +420,34 @@ character|-|handling code have been moved back inline. When \type {\tracingcommands} is on, this is visible because the full word is reported, instead of just the initial character. +Because we tend to make hard codes behaviour configurable a few new primitives +have been added: + +\starttyping +\hyphenpenaltymode +\automatichyphenpenalty +\explicithyphenpenalty +\stoptyping + +The first parameter has the following consequences for automatic discs (the ones +resulting from an \type {\exhyphenchar}: + +\starttabulate[|Tc|l|l|] +\BC mode \BC automatic disc \type{-} \BC explicit disc \type{\-} \NC \NR +\HL +\NC 0 \NC \type {\exhyphenpenalty} \NC \type {\exhyphenpenalty} \NC \NR +\NC 1 \NC \type {\hyphenpenalty} \NC \type {\hyphenpenalty} \NC \NR +\NC 2 \NC \type {\exhyphenpenalty} \NC \type {\hyphenpenalty} \NC \NR +\NC 3 \NC \type {\hyphenpenalty} \NC \type {\exhyphenpenalty} \NC \NR +\NC 4 \NC \type {\automatichyphenpenalty} \NC \type {\explicithyphenpenalty} \NC \NR +\NC 5 \NC \type {\exhyphenpenalty} \NC \type {\explicithyphenpenalty} \NC \NR +\NC 6 \NC \type {\hyphenpenalty} \NC \type {\explicithyphenpenalty} \NC \NR +\NC 7 \NC \type {\automatichyphenpenalty} \NC \type {\exhyphenpenalty} \NC \NR +\NC 8 \NC \type {\automatichyphenpenalty} \NC \type {\hyphenpenalty} \NC \NR +\stoptabulate + +other values do what we always did in \LUATEX: insert \type {\exhyphenpenalty}. + \section[patternsexceptions]{Loading patterns and exceptions} The hyphenation algorithm in \LUATEX\ is quite different from the one in \TEX82, @@ -703,3 +891,17 @@ initialized due to \type {\savinghyphcodes} being larger than zero. \stopchapter \stopcomponent + +% \parindent0pt \hsize=1.1cm +% 12-34-56 \par +% 12-34-\hbox{56} \par +% 12-34-\vrule width 1em height 1.5ex \par +% 12-\hbox{34}-56 \par +% 12-\vrule width 1em height 1.5ex-56 \par +% \hjcode`\1=`\1 \hjcode`\2=`\2 \hjcode`\3=`\3 \hjcode`\4=`\4 \vskip.5cm +% 12-34-56 \par +% 12-34-\hbox{56} \par +% 12-34-\vrule width 1em height 1.5ex \par +% 12-\hbox{34}-56 \par +% 12-\vrule width 1em height 1.5ex-56 \par + |