diff options
Diffstat (limited to 'tex/context/base/supp-lan.tex')
-rw-r--r-- | tex/context/base/supp-lan.tex | 1614 |
1 files changed, 927 insertions, 687 deletions
diff --git a/tex/context/base/supp-lan.tex b/tex/context/base/supp-lan.tex index e64967aef..a709da662 100644 --- a/tex/context/base/supp-lan.tex +++ b/tex/context/base/supp-lan.tex @@ -1,687 +1,927 @@ -%D \module
-%D [ file=supp-lan,
-%D version=1997.03.20,
-%D title=\CONTEXT\ Support Macros,
-%D subtitle=Language Options,
-%D author=Hans Hagen,
-%D date=\currentdate,
-%D copyright={PRAGMA / Hans Hagen \& Ton Otten}]
-%C
-%C This module is part of the \CONTEXT\ macro||package and is
-%C therefore copyrighted by \PRAGMA. Non||commercial use is
-%C granted.
-
-%D \gdef\starttest%
-%D {\blanko
-%D \noindent
-%D \halign\bgroup\tt##\hskip2em&##\hskip2em&##\cr}
-%D
-%D \gdef\stoptest%
-%D {\egroup
-%D \blanko}
-%D
-%D \gdef\test#1%
-%D {\convertargument#1\to\ascii\ascii&\hyphenatedword{#1}\cr}
-
-%D One of \TEX's strong points in building paragraphs is the way
-%D hyphenations are handled. Although for real good hyphenation
-%D of non||english languages some extensions to the program are
-%D needed, fairly good results can be reached with the standard
-%D mechanisms and an additional macro, at least in Dutch.
-
-\unprotect
-
-%D \CONTEXT\ originates in the wish to typeset educational
-%D materials, especially in a technical environment. In
-%D production oriented environments, a lot of compound words
-%D are used. Because the Dutch language poses no limits on
-%D combining words, we often favor putting dashes between those
-%D words, because it facilitates reading, at least for those
-%D who are not that accustomed to it.
-%D
-%D In \TEX\ compound words, separated by a hyphen, are not
-%D hyphenated at all. In spite of the multiple pass paragraph
-%D typesetting this can lead to parts of words sticking into
-%D the margin. The solution lays in saying
-%D \type{spoelwater||terugwinunit} instead of
-%D \type{spoelwater-terugwinunit}. By using a one character
-%D command like \type{|}, delimited by the same character
-%D \type{|}, we get ourselves both a decent visualization (in
-%D \TEXEDIT\ and colored verbatim we color these commands
-%D yellow) and an efficient way of combining words.
-%D
-%D The sequence \type{||} simply leads to two words connected by
-%D a hyphen. Because we want to distinguish such a hyphen from
-%D the one inserted when \TEX\ hyphenates a word, we use a bit
-%D longer one.
-%D
-%D \hyphenation {spoel-wa-ter te-rug-win-unit}
-%D
-%D \starttest
-%D \test {spoelwater||terugwinunit}
-%D \stoptest
-%D
-%D As we already said, the \type{|} is a command. This commands
-%D accepts an optional argument before it's delimiter, which is
-%D also a \type{|}.
-%D
-%D \hyphenation {po-ly-meer che-mie}
-%D
-%D \starttest
-%D \test {polymeer|*|chemie}
-%D \stoptest
-%D
-%D Arguments like \type{*} are not interpreted and inserted
-%D directly, in contrary to arguments like:
-%D
-%D \starttest
-%D \test {polymeer|~|chemie}
-%D \test {|(|polymeer|)|chemie}
-%D \test {polymeer|(|chemie|)| }
-%D \stoptest
-%D
-%D Although such situations seldom occur |<|we typeset thousands
-%D of pages before we encountered one that forced us to enhance
-%D this mechanism|>| we also have to take care of comma's.
-%D
-%D \hyphenation {uit-stel-len}
-%D
-%D \starttest
-%D \test {op||, in|| en uitstellen}
-%D \stoptest
-%D
-%D The next special case (concerning quotes) was brought to my
-%D attention by Piet Tutelaers, one of the driving forces
-%D behind rebuilding hyphenation patterns for the dutch
-%D language.\voetnoot{In 1996 the spelling of the dutch
-%D language has been slightly reformed which made this topic
-%D actual again.} We'll also take care of this case.
-%D
-%D \starttest
-%D \test {AOW|'|er}
-%D \test {cd|'|tje}
-%D \test {ex|-|PTT|'|er}
-%D \test {rock|-|'n|-|roller}
-%D \stoptest
-%D
-%D Tobias Burnus pointed out that I should also support
-%D something like
-%D
-%D \starttest
-%D \test {well|_|known}
-%D \stoptest
-%D
-%D to strees the compoundness of hyphenated words.
-%D
-%D Of course we also have to take care of the special case:
-%D
-%D \starttest
-%D \test {text||color and ||font}
-%D \stoptest
-
-%D \macros
-%D {installdiscretionaries}
-%D {}
-%D
-%D The mechanism described here is one of the older inner parts
-%D of \CONTEXT. The most recent extensions concerns some
-%D special cases as well as the possibility to install other
-%D characters as delimiters. The prefered way of specifying
-%D compound words is using \type{||}, which is installed by:
-%D
-%D \starttypen
-%D \installdiscretionaries || -
-%D \stoptypen
-%D
-%D Some alternative definitions are:
-%D
-%D \startbuffer
-%D \installdiscretionaries ** -
-%D \installdiscretionaries ++ -
-%D \installdiscretionaries // -
-%D \installdiscretionaries ~~ -
-%D \stopbuffer
-%D
-%D \typebuffer
-%D
-%D after which we can say:
-%D
-%D \bgroup
-%D \haalbuffer
-%D \starttest
-%D \test {test**test**test}
-%D \test {test++test++test}
-%D \test {test//test//test}
-%D \test {test~~test~~test}
-%D \stoptest
-%D \egroup
-
-%D \macros
-%D {compoundhyphen,
-%D beginofsubsentence,endofsubsentence}
-%D {}
-%D
-%D Now let's go to the macros. First we define some variables.
-%D In the main \CONTEXT\ modules these can be tuned by a setup
-%D command. Watch the (maybe) better looking compound hyphen.
-
-\def\compoundhyphen {{-}\kern-.25ex{-}}
-\def\beginofsubsentence {---}
-\def\endofsubsentence {---}
-
-%D The last two variables are needed for subsentences
-%D |<|like this one|>| which we did not yet mention.
-%D
-%D We want to enable breaking but at the same time don't want
-%D compound characters like |-| or || to be separated from the
-%D words. \TEX\ hackers will recognise the next two macro's:
-
-\def\prewordbreak {\penalty10000\hskip0pt\relax}
-\def\postwordbreak {\penalty0\prewordbreak}
-
-%D We first show the original implementation, which only
-%D supports \type{|} as command and delimiter. Before
-%D activating \type{|} we save it's value:
-%D
-%D \starttypen
-%D \edef\domathmodediscretionary{\string|}
-%D \stoptypen
-%D
-%D after which we're ready to define it's meaning to:
-%D
-%D \starttypen
-%D \catcode`\|=\@@active
-%D
-%D \unexpanded\def|%
-%D {\ifmmode
-%D \expandafter\domathmodediscretionary
-%D \else
-%D \expandafter\dotextmodediscretionary
-%D \fi}
-%D \stoptypen
-%D
-%D We need a two stage \type{\futurelet} because we want to
-%D look ahead for both the compound character definition and
-%D the (optional) comma that follows it, and because we want to
-%D prevent that \TEX\ puts this comma on the next line. We use
-%D \type{\next} for easy and fast checking of the argument, we
-%D save this argument (which can consist of more tokens) and
-%D also save the character following the \type{|#1|} in
-%D \type{\nextnext}.
-%D
-%D \starttypen
-%D \def\dotextmodediscretionary%
-%D {\bgroup
-%D \futurelet\next\dodotextmodediscretionary}
-%D
-%D \def\dodotextmodediscretionary#1|%
-%D {\def\betweendiscretionaries{#1}%
-%D \futurelet\nextnext\dododotextmodediscretionary}
-%D \stoptypen
-%D
-%D The main macro consists of quite some \type{\ifx} tests
-%D while \type{\checkafterdiscretionary} handles the commas.
-%D We show the simplified version here:
-%D
-%D \starttypen
-%D \def\dododotextmodediscretionary%
-%D {\let\nextnextnext=\egroup
-%D \ifx |\next
-%D \checkafterdiscretionary
-%D \prewordbreak\hbox{\compoundhyphen\nextnext}\allowbreak
-%D \else\ifx=\next
-%D \prewordbreak\compoundhyphen
-%D \else\ifx~\next
-%D \discretionary{-}{}{\thinspace}\postwordbreak
-%D \else\ifx(\next
-%D \prewordbreak\discretionary{}{(-}{(}\prewordbreak
-%D \else\ifx)\next
-%D \prewordbreak\discretionary{-)}{}{)}\prewordbreak
-%D \else\ifx'\next
-%D \prewordbreak\discretionary{-}{}{'}\postwordbreak
-%D \else
-%D \checkafterdiscretionary
-%D \prewordbreak\hbox{\betweendiscretionaries\nextnext}\allowbreak
-%D \fi\fi\fi\fi\fi\fi
-%D \nextnextnext}
-%D
-%D \def\checkafterdiscretionary%
-%D {\ifx,\nextnext
-%D \def\nextnextnext{\afterassignment\egroup\let\next=}%
-%D \else
-%D \let\nextnext=\relax
-%D \fi}
-%D \stoptypen
-%D
-%D Handling \type{(} and \type{)} is a a bit special, because
-%D \TEX\ sees them as decent hyphenation points, according to
-%D their \type{\lccode} being non||zero. For the same reason,
-%D later on in this module we cannot manipulate the
-%D \type{\lccode} but take the \type{\uccode}.
-
-%D The most recent implementation is more advanced. As
-%D demonstrated we can install delimiters, like:
-%D
-%D \starttypen
-%D \installdiscretionaries || \compoundhyphen
-%D \stoptypen
-%D
-%D This time we have to use a bit more clever way of saving the
-%D math mode specification of the character we're going to
-%D make active. We also save the user supplied compound hyphen.
-%D We show the a bit more traditional implementation first.
-%D
-%D \starttypen
-%D \def\installdiscretionaries#1%
-%D {\catcode`#1\@@other
-%D \expandafter\doinstalldiscretionaries\string#1}
-%D
-%D \def\doinstalldiscretionaries#1%
-%D {\setvalue{mathmodediscretionary#1}{#1}%
-%D \catcode`#1\@@active
-%D \dodoinstalldiscretionaries}
-%D
-%D \def\dodoinstalldiscretionaries#1#2%
-%D {\setvalue{textmodediscretionary\string#1}{#2}%
-%D \unexpanded\def#1{\discretionarycommand#1}}
-%D \stoptypen
-%D
-%D A bit more \CATCODE\ and character trickery enables us to
-%D discard the two intermediate steps. This trick originates
-%D on page~394 of the \TEX book, in the appendix full of
-%D dirty tricks. The second argument has now become redundant,
-%D but I decided to reserve it for future use. At least it
-%D remembers us of the symmetry.
-
-\def\installdiscretionaries#1#2#3%
- {\setvalue{mathmodediscretionary\string#1}{\char`#1}%
- \setvalue{textmodediscretionary\string#1}{#3}%
- \catcode`#1=\@@active
- \scratchcounter=\the\uccode`~
- \uccode`~=`#1
- \uppercase{\unexpanded\def~{\discretionarycommand~}}%
- \uccode`~=\scratchcounter}
-
-\def\dohandlemathmodebar#1%
- {\getvalue{mathmodediscretionary\string#1}}
-
-\def\discretionarycommand%
- {\ifmmode
- \expandafter\dohandlemathmodebar
- \else
- \expandafter\dotextmodediscretionary
- \fi}
-
-%D Although adapting character codes and making characters
-%D active can interfere with other features of macropackages,
-%D normally there should be no problems with things like:
-%D
-%D \starttypen
-%D \installdiscretionary || +
-%D \installdiscretionary ++ =
-%D \stoptypen
-%D
-%D The real work is done by the next set of macros. We have
-%D to use a double \type{\futurelet} because we have to take
-%D following characters into account.
-
-\def\dotextmodediscretionary#1%
- {\bgroup
- \def\dodotextmodediscretionary##1#1%
- {\def\betweendiscretionary{##1}%
- \futurelet\nextnext\dododotextmodediscretionary}%
- \let\discretionarycommand=#1%
- \def\textmodediscretionary{\getvalue{textmodediscretionary\string#1}}%
- \futurelet\next\dodotextmodediscretionary}
-
-\def\dododotextmodediscretionary%
- {\let\nextnextnext=\egroup
- \ifx\discretionarycommand\next
- \checkafterdiscretionary
- \bgroup
- \checkbeforediscretionary
- \prewordbreak\hbox{\textmodediscretionary\nextnext}\allowbreak
- \egroup
- \else\ifx=\next
- \prewordbreak\textmodediscretionary
- \else\ifx~\next
- \prewordbreak\discretionary{-}{}{\thinspace}\postwordbreak
- \else\ifx_\next
- \prewordbreak\discretionary{\textmodediscretionary}
- {\textmodediscretionary}{\textmodediscretionary}\prewordbreak
- \else\ifx(\next
- \ifdim\lastskip>\!!zeropoint\relax
- (\prewordbreak
- \else
- \prewordbreak\discretionary{}{(-}{(}\prewordbreak
- \fi
- \else\ifx)\next
- \ifx\nextnext\blankspace
- \prewordbreak)\relax
- \else
- \prewordbreak\discretionary{-)}{}{)}\prewordbreak
- \fi
- \else\ifx'\next
- \prewordbreak\discretionary{-}{}{'}\postwordbreak
- \else\ifx<\next
- \beginofsubsentence\prewordbreak\beginofsubsentencespacing
- \else\ifnum\uccode`>=\nextuccode
- \endofsubsentencespacing\prewordbreak\endofsubsentence
- \else
- \checkafterdiscretionary
- \bgroup
- \checkbeforediscretionary
- \prewordbreak\hbox{\betweendiscretionary\nextnext}\allowbreak
- \egroup
- \fi\fi\fi\fi\fi\fi\fi\fi\fi
- \nextnextnext}
-
-\def\checkbeforediscretionary%
- {\setbox0=\lastbox
- \ifdim\wd0=\!!zeropoint
- \let\postwordbreak=\prewordbreak
- \fi
- \box0\relax}
-
-\def\checkafterdiscretionary%
- {\ifx,\nextnext
- \def\nextnextnext{\afterassignment\egroup\let\next=}%
- \else
- \let\nextnext=\relax
- \fi}
-
-%D The macro \type{\checkbeforediscretionary} takes care of
-%D loners like \type{||word}, while it counterpart
-%D \type{\checkafterdiscretionary} is responsible for handling
-%D the comma.
-
-%D \macros
-%D {beginofsubsentencespacing,endofsubsentencespacing}
-%D {}
-%D
-%D In the previous macros we provided two hooks which can be
-%D used to support nested sub||sentences. In \CONTEXT\ these
-%D hooks are used to insert a small space when needed.
-
-\let\beginofsubsentencespacing=\relax
-\let\endofsubsentencespacing =\relax
-
-%D Before we show some more tricky alternative, we first install
-%D the mechanism:
-
-\installdiscretionaries || \compoundhyphen
-
-%D One of the drawbacks of this mechanism is that characters can
-%D be made active afterwards. The next alternative can be used
-%D in such situations. This time we don't compare the arguments
-%D directly but use the \type{\uccode}'s instead. \TEX\
-%D initializes these codes of the alphabetics glyphs to their
-%D uppercase counterparts. Normally the other characters remain
-%D zero. If so, we can use the \type{\uccode} as a signal.
-
-%D \macros
-%D {enableactivediscretionaries}
-%D {}
-%D
-%D The more advanced mechanism is activated by calling:
-%D
-%D \starttypen
-%D \enableactivediscretionaries
-%D \stoptypen
-%D
-%D which is defined as:
-
-\def\enableactivediscretionaries%
- {\uccode`'=`'\relax \uccode`~=`~\relax \uccode`_=`_\relax
- \uccode`(=`(\relax \uccode`)=`)\relax \uccode`==`=\relax
- \uccode`<=`<\relax \uccode`>=`>\relax
- \let\dotextmodediscretionary = \activedotextmodediscretionary
- \let\dododotextmodediscretionary = \activedododotextmodediscretionary}
-
-%D We only have to redefine two macros. While saving the
-%D \type{\uccode} in a macro we have to take care of empty
-%D arguments, like in \type{||}.
-
-\def\activedotextmodediscretionary#1%
- {\bgroup
- \def\dodotextmodediscretionary##1#1%
- {\def\betweendiscretionary{##1}%
- \def\nextuccode####1####2\relax%
- {\ifcat\noexpand####1\noexpand\relax
- \edef\nextuccode{0}%
- \else
- \edef\nextuccode{\the\uccode`####1}%
- \fi}%
- \nextuccode##1@\relax
- \futurelet\nextnext\dododotextmodediscretionary}%
- \let\discretionarycommand=#1%
- \def\textmodediscretionary{\getvalue{textmodediscretionary\string#1}}%
- \futurelet\next\dodotextmodediscretionary}
-
-%D This time we use \type{\ifnum}:
-
-\def\activedododotextmodediscretionary%
- {\let\nextnextnext=\egroup
- \ifx\discretionarycommand\next
- \checkafterdiscretionary
- \bgroup
- \checkbeforediscretionary
- \prewordbreak\hbox{\textmodediscretionary\nextnext}\allowbreak
- \egroup
- \else\ifnum\uccode`==\nextuccode
- \prewordbreak\textmodediscretionary
- \else\ifnum\uccode`~=\nextuccode
- \prewordbreak\discretionary{-}{}{\thinspace}\postwordbreak
- \else\ifnum\uccode`_=\nextuccode
- \prewordbreak\discretionary{\textmodediscretionary}
- {\textmodediscretionary}{\textmodediscretionary}\prewordbreak
- \else\ifnum\uccode`(=\nextuccode
- \ifdim\lastskip>\!!zeropoint\relax
- (\prewordbreak
- \else
- \prewordbreak\discretionary{}{(-}{(}\prewordbreak
- \fi
- \else\ifnum\uccode`)=\nextuccode
- \ifx\nextnext\blankspace
- \prewordbreak)\relax
- \else
- \prewordbreak\discretionary{-)}{}{)}\prewordbreak
- \fi
- \else\ifnum\uccode`'=\nextuccode
- \prewordbreak\discretionary{-}{}{'}\postwordbreak
- \else\ifnum\uccode`<=\nextuccode
- \beginofsubsentence\prewordbreak\beginofsubsentencespacing
- \else\ifnum\uccode`>=\nextuccode
- \endofsubsentencespacing\prewordbreak\endofsubsentence
- \else
- \checkafterdiscretionary
- \bgroup
- \checkbeforediscretionary
- \prewordbreak\hbox{\betweendiscretionary\nextnext}\allowbreak
- \egroup
- \fi\fi\fi\fi\fi\fi\fi\fi\fi
- \nextnextnext}
-
-%D Now we can safely do things like: \enableactivediscretionaries
-%D
-%D \starttypen
-%D \catcode`<=\@@active \def<{hello there}
-%D \catcode`>=\@@active \def>{hello there}
-%D \catcode`(=\@@active \def({hello there}
-%D \catcode`)=\@@active \def){hello there}
-%D \stoptypen
-%D
-%D In normal day||to||day production of texts this kind of
-%D activation is seldom used.\voetnoot{In the \CONTEXT\ manual
-%D the \type{<} and \type{>} are made active and used for some
-%D cross||reference trickery.} If so, we have to take care of
-%D the math mode explicitly, just like we did when making
-%D \type{|} active. It can be confusing too, especially when we
-%D load macropackages afterwards that make use of \type{<} in
-%D \type{\ifnum} or \type{\ifdim} statements.
-
-%D \macros
-%D {installcompoundcharacter}
-%D {}
-%D
-%D When Tobias Burnus started translating the dutch manual of
-%D \PPCHTEX\ into german, he suggested to let \CONTEXT\ support
-%D the \type{german.sty} method of handling compound
-%D characters, especially the umlaut. This package is meant for
-%D use with \PLAIN\ \TEX\ as well as \LATEX.
-%D
-%D I decided to implement compound character support as
-%D versatile as possible. As a result one can define his own
-%D compound character support, like:
-%D
-%D \starttypen
-%D \installcompoundcharacter "a {\"a}
-%D \installcompoundcharacter "e {\"e}
-%D \installcompoundcharacter "i {\"i}
-%D \installcompoundcharacter "u {\"u}
-%D \installcompoundcharacter "o {\"o}
-%D \installcompoundcharacter "s {\SS}
-%D \stoptypen
-%D
-%D or even
-%D
-%D \starttypen
-%D \installcompoundcharacter "ck {\discretionary {k-}{k}{ck}}
-%D \installcompoundcharacter "ff {\discretionary{ff-}{f}{ff}}
-%D \stoptypen
-%D
-%D The support is not limited to alphabetic characters, so the
-%D next definition is also valid.
-%D
-%D \starttypen
-%D \installcompoundcharacter ". {.\doifnextcharelse{\spacetoken}{}{\kern.125em}}
-%D \stoptypen
-%D
-%D The implementation looks familiar and uses the same tricks as
-%D mentioned earlier in this module. We take care of two
-%D arguments, which complicates things a bit.
-
-\def\@nc@{@nc@} % normal character
-\def\@cc@{@cc@} % compound character
-\def\@cs@{@cs@} % compound characters
-
-\def\installcompoundcharacter #1#2#3 #4% {{#4}} keeps move local
- {\setvalue{\@nc@\string#1}{\char`#1}%
- \def\!!stringa{#3}%
- \ifx\!!stringa\empty
- \setvalue{\@cc@\string#1\string#2}{{#4}}%
- \else
- \setvalue{\@cs@\string#1\string#2\string#3}{{#4}}%
- \fi
- \catcode`#1=\@@active
- \scratchcounter=\the\uccode`~
- \uccode`~=`#1
- \uppercase{\unexpanded\def~{\handlecompoundcharacter~}}%
- \uccode`~=\scratchcounter}
-
-%D In handling the compound characters we have to take care of
-%D \type{\bgroup} and \type{\egroup} tokens, so we end up with
-%D a multi||step interpretation macro. We look ahead for a
-%D \type{\bgroup}, \type{\egroup} or \type{\blankspace}. Being
-%D no user of this mechanism, the credits for testing them goes
-%D to Tobias Burnus, the first german user of \CONTEXT.
-%D
-%D We define these macros as \type{\long} because we can
-%D expect \type{\par} tokens. We need to look into the future
-%D with \type{\futurelet} to prevent spaces from
-%D disappearing.
-
-\def\handlecompoundcharacter#1%
- {\def\dohandlecompoundcharacter%
- {\ifx\next\bgroup
- %\def\next{\dodohandlecompoundcharacter#1}% % handle "{ee} -> \"ee
- %\let\next=\relax % forget "{ee} -> ee
- \def\next{\handlecompoundcharacterone#1}% % ignore "{ee} -> "ee
- \else\ifx\next\egroup
- \let\next=\relax
- \else\ifx\next\blankspace
- \let\next=\relax
- \else
- \def\next{\dodohandlecompoundcharacter#1}%
- \fi\fi\fi
- \next}%
- \futurelet\next\dohandlecompoundcharacter}
-
-\def\dodohandlecompoundcharacter#1#2%
- {\def\dododohandlecompoundcharacter%
- {\ifx\next\bgroup
- \def\next{\handlecompoundcharacterone#1#2}%
- \else\ifx\next\egroup
- \def\next{\handlecompoundcharacterone#1#2}%
- \else\ifx\next\blankspace
- \def\next{\handlecompoundcharacterone#1#2}%
- \else
- \def\next{\handlecompoundcharactertwo#1#2}%
- \fi\fi\fi
- \next}%
- \futurelet\next\dododohandlecompoundcharacter}
-
-%D Besides taken care of the grouping and space tokens, we have
-%D to deal with three situations. First we look if the next
-%D character equals the first one, if so, then we just insert
-%D the original. Next we look if indeed a compound character is
-%D defined. We either execute the compound character or just
-%D insert the first. So we have
-%D
-%D \starttypen
-%D <key><key> <key><known> <key><unknown>
-%D \stoptypen
-%D
-%D In later modules we will see how these commands are used.
-
-\long\def\handlecompoundcharacterone#1#2%
- {\ifx#1#2%
- \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}}%
- \else
- \expandafter\ifx\csname\@cc@\string#1\string#2\endcsname\relax
- \def\next{\getvalue{\@nc@\string#1}#2}%
- \else
- \def\next{\getvalue{\@cc@\string#1\string#2}}%
- \fi
- \fi
- \next}
-
-\long\def\handlecompoundcharactertwo#1#2#3%
- {\ifx#1#2%
- \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}#3}%
- \else
- \@EA\ifx\csname\@cs@\string#1\string#2\string#3\endcsname\relax
- \expandafter\ifx\csname\@cc@\string#1\string#2\endcsname\relax
- \def\next{\getvalue{\@nc@\string#1}#2#3}%
- \else
- \def\next{\getvalue{\@cc@\string#1\string#2}#3}%
- \fi
- \else
- \def\next{\getvalue{\@cs@\string#1\string#2\string#3}}%
- \fi
- \fi
- \next}
-
-%D \macros
-%D {midworddiscretionary}
-%D
-%D If needed, one can add a discretionary hyphen using \type
-%D {\midworddiscretionary}. This macro does the same as
-%D \PLAIN\ \TEX's \type {\-}, but, like the ones implemented
-%D earlier, this one also looks ahead for spaces and grouping
-%D tokens.
-
-\def\domidworddiscretionary%
- {\ifx\next\blankspace\else
- \ifx\next\bgroup \else
- \ifx\next\egroup \else
- \discretionary{-}{}{}%
- \fi\fi\fi}
-
-\def\midworddiscretionary%
- {\futurelet\next\domidworddiscretionary}
-
-\protect
-
-\endinput
-
\ No newline at end of file +%D \module +%D [ file=supp-lan, +%D version=1997.03.20, +%D title=\CONTEXT\ Support Macros, +%D subtitle=Language Options, +%D author=Hans Hagen, +%D date=\currentdate, +%D copyright={PRAGMA / Hans Hagen \& Ton Otten}] +%C +%C This module is part of the \CONTEXT\ macro||package and is +%C therefore copyrighted by \PRAGMA. Non||commercial use is +%C granted. + +%D \gdef\starttest% +%D {\blanko +%D \noindent +%D \halign\bgroup\tt##\hskip2em&##\hskip2em&##\cr} +%D +%D \gdef\stoptest% +%D {\egroup +%D \blanko} +%D +%D \gdef\test#1% +%D {\convertargument#1\to\ascii\ascii&\hyphenatedword{#1}\cr} + +%D One of \TEX's strong points in building paragraphs is the way +%D hyphenations are handled. Although for real good hyphenation +%D of non||english languages some extensions to the program are +%D needed, fairly good results can be reached with the standard +%D mechanisms and an additional macro, at least in Dutch. + +\unprotect + +\writestatus{loading}{Context Support Macros / Language Options} + +%D \CONTEXT\ originates in the wish to typeset educational +%D materials, especially in a technical environment. In +%D production oriented environments, a lot of compound words +%D are used. Because the Dutch language poses no limits on +%D combining words, we often favor putting dashes between those +%D words, because it facilitates reading, at least for those +%D who are not that accustomed to it. +%D +%D In \TEX\ compound words, separated by a hyphen, are not +%D hyphenated at all. In spite of the multiple pass paragraph +%D typesetting this can lead to parts of words sticking into +%D the margin. The solution lays in saying +%D \type{spoelwater||terugwinunit} instead of +%D \type{spoelwater-terugwinunit}. By using a one character +%D command like \type{|}, delimited by the same character +%D \type{|}, we get ourselves both a decent visualization (in +%D \TEXEDIT\ and colored verbatim we color these commands +%D yellow) and an efficient way of combining words. +%D +%D The sequence \type{||} simply leads to two words connected by +%D a hyphen. Because we want to distinguish such a hyphen from +%D the one inserted when \TEX\ hyphenates a word, we use a bit +%D longer one. +%D +%D \hyphenation {spoel-wa-ter te-rug-win-unit} +%D +%D \starttest +%D \test {spoelwater||terugwinunit} +%D \stoptest +%D +%D As we already said, the \type{|} is a command. This commands +%D accepts an optional argument before it's delimiter, which is +%D also a \type{|}. +%D +%D \hyphenation {po-ly-meer che-mie} +%D +%D \starttest +%D \test {polymeer|*|chemie} +%D \stoptest +%D +%D Arguments like \type{*} are not interpreted and inserted +%D directly, in contrary to arguments like: +%D +%D \starttest +%D \test {polymeer|~|chemie} +%D \test {|(|polymeer|)|chemie} +%D \test {polymeer|(|chemie|)| } +%D \stoptest +%D +%D Although such situations seldom occur |<|we typeset thousands +%D of pages before we encountered one that forced us to enhance +%D this mechanism|>| we also have to take care of comma's. +%D +%D \hyphenation {uit-stel-len} +%D +%D \starttest +%D \test {op||, in|| en uitstellen} +%D \stoptest +%D +%D The next special case (concerning quotes) was brought to my +%D attention by Piet Tutelaers, one of the driving forces +%D behind rebuilding hyphenation patterns for the dutch +%D language.\voetnoot{In 1996 the spelling of the dutch +%D language has been slightly reformed which made this topic +%D actual again.} We'll also take care of this case. +%D +%D \starttest +%D \test {AOW|'|er} +%D \test {cd|'|tje} +%D \test {ex|-|PTT|'|er} +%D \test {rock|-|'n|-|roller} +%D \stoptest +%D +%D Tobias Burnus pointed out that I should also support +%D something like +%D +%D \starttest +%D \test {well|_|known} +%D \stoptest +%D +%D to strees the compoundness of hyphenated words. +%D +%D Of course we also have to take care of the special case: +%D +%D \starttest +%D \test {text||color and ||font} +%D \stoptest + +%D \macros +%D {installdiscretionaries} +%D +%D The mechanism described here is one of the older inner parts +%D of \CONTEXT. The most recent extensions concerns some +%D special cases as well as the possibility to install other +%D characters as delimiters. The prefered way of specifying +%D compound words is using \type{||}, which is installed by: +%D +%D \starttypen +%D \installdiscretionaries || - +%D \stoptypen +%D +%D Some alternative definitions are: +%D +%D \startbuffer +%D \installdiscretionaries ** - +%D \installdiscretionaries ++ - +%D \installdiscretionaries // - +%D \installdiscretionaries ~~ - +%D \stopbuffer +%D +%D \typebuffer +%D +%D after which we can say: +%D +%D \bgroup +%D \haalbuffer +%D \starttest +%D \test {test**test**test} +%D \test {test++test++test} +%D \test {test//test//test} +%D \test {test~~test~~test} +%D \stoptest +%D \egroup + +%D \macros +%D {compoundhyphen, +%D beginofsubsentence,endofsubsentence} +%D {} +%D +%D Now let's go to the macros. First we define some variables. +%D In the main \CONTEXT\ modules these can be tuned by a setup +%D command. Watch the (maybe) better looking compound hyphen. + +\def\compoundhyphen {{-}\kern-.25ex{-}} +\def\beginofsubsentence {---} +\def\endofsubsentence {---} + +%D The last two variables are needed for subsentences +%D |<|like this one|>| which we did not yet mention. +%D +%D We want to enable breaking but at the same time don't want +%D compound characters like |-| or || to be separated from the +%D words. \TEX\ hackers will recognise the next two macro's: + +\def\prewordbreak {\penalty10000\hskip0pt\relax} +\def\postwordbreak {\penalty0\prewordbreak} + +%D We first show the original implementation, which only +%D supports \type{|} as command and delimiter. Before +%D activating \type{|} we save it's value: +%D +%D \starttypen +%D \edef\domathmodediscretionary{\string|} +%D \stoptypen +%D +%D after which we're ready to define it's meaning to: +%D +%D \starttypen +%D \catcode`\|=\@@active +%D +%D \unexpanded\def|% +%D {\ifmmode +%D \expandafter\domathmodediscretionary +%D \else +%D \expandafter\dotextmodediscretionary +%D \fi} +%D \stoptypen +%D +%D We need a two stage \type{\futurelet} because we want to +%D look ahead for both the compound character definition and +%D the (optional) comma that follows it, and because we want to +%D prevent that \TEX\ puts this comma on the next line. We use +%D \type{\next} for easy and fast checking of the argument, we +%D save this argument (which can consist of more tokens) and +%D also save the character following the \type{|#1|} in +%D \type{\nextnext}. +%D +%D \starttypen +%D \def\dotextmodediscretionary% +%D {\bgroup +%D \futurelet\next\dodotextmodediscretionary} +%D +%D \def\dodotextmodediscretionary#1|% +%D {\def\betweendiscretionaries{#1}% +%D \futurelet\nextnext\dododotextmodediscretionary} +%D \stoptypen +%D +%D The main macro consists of quite some \type{\ifx} tests +%D while \type{\checkafterdiscretionary} handles the commas. +%D We show the simplified version here: +%D +%D \starttypen +%D \def\dododotextmodediscretionary% +%D {\let\nextnextnext=\egroup +%D \ifx |\next +%D \checkafterdiscretionary +%D \prewordbreak\hbox{\compoundhyphen\nextnext}\allowbreak +%D \else\ifx=\next +%D \prewordbreak\compoundhyphen +%D \else\ifx~\next +%D \discretionary{-}{}{\thinspace}\postwordbreak +%D \else\ifx(\next +%D \prewordbreak\discretionary{}{(-}{(}\prewordbreak +%D \else\ifx)\next +%D \prewordbreak\discretionary{-)}{}{)}\prewordbreak +%D \else\ifx'\next +%D \prewordbreak\discretionary{-}{}{'}\postwordbreak +%D \else +%D \checkafterdiscretionary +%D \prewordbreak\hbox{\betweendiscretionaries\nextnext}\allowbreak +%D \fi\fi\fi\fi\fi\fi +%D \nextnextnext} +%D +%D \def\checkafterdiscretionary% +%D {\ifx,\nextnext +%D \def\nextnextnext{\afterassignment\egroup\let\next=}% +%D \else +%D \let\nextnext=\relax +%D \fi} +%D \stoptypen +%D +%D Handling \type{(} and \type{)} is a a bit special, because +%D \TEX\ sees them as decent hyphenation points, according to +%D their \type{\lccode} being non||zero. For the same reason, +%D later on in this module we cannot manipulate the +%D \type{\lccode} but take the \type{\uccode}. + +%D The most recent implementation is more advanced. As +%D demonstrated we can install delimiters, like: +%D +%D \starttypen +%D \installdiscretionaries || \compoundhyphen +%D \stoptypen +%D +%D This time we have to use a bit more clever way of saving the +%D math mode specification of the character we're going to +%D make active. We also save the user supplied compound hyphen. +%D We show the a bit more traditional implementation first. +%D +%D \starttypen +%D \def\installdiscretionaries#1% +%D {\catcode`#1\@@other +%D \expandafter\doinstalldiscretionaries\string#1} +%D +%D \def\doinstalldiscretionaries#1% +%D {\setvalue{mathmodediscretionary#1}{#1}% +%D \catcode`#1\@@active +%D \dodoinstalldiscretionaries} +%D +%D \def\dodoinstalldiscretionaries#1#2% +%D {\setvalue{textmodediscretionary\string#1}{#2}% +%D \unexpanded\def#1{\discretionarycommand#1}} +%D \stoptypen +%D +%D A bit more \CATCODE\ and character trickery enables us to +%D discard the two intermediate steps. This trick originates +%D on page~394 of the \TEX book, in the appendix full of +%D dirty tricks. The second argument has now become redundant, +%D but I decided to reserve it for future use. At least it +%D remembers us of the symmetry. + +\beginTEX + +\def\installdiscretionaries#1#2#3% + {\convertargument#1\to\ascii + \setevalue{mathmodediscretionary\string#1}{\ascii}% + \setvalue{textmodediscretionary\string#1}{#3}% + \catcode`#1=\@@active + \scratchcounter=\the\uccode`~ + \uccode`~=`#1 + \uppercase{\unexpanded\def~{\discretionarycommand~}}% + \uccode`~=\scratchcounter} + +\endTEX + +\beginETEX \detokenize + +\def\installdiscretionaries#1#2#3% + {\setevalue{mathmodediscretionary\string#1}{\detokenize{#1}}% + \setvalue{textmodediscretionary\string#1}{#3}% + \catcode`#1=\@@active + \scratchcounter=\the\uccode`~ + \uccode`~=`#1 + \uppercase{\unexpanded\def~{\discretionarycommand~}}% + \uccode`~=\scratchcounter} + +\endETEX + +\def\dohandlemathmodebar#1% + {\getvalue{mathmodediscretionary\string#1}} + +\def\discretionarycommand% + {\relax\ifmmode + \expandafter\dohandlemathmodebar + \else + \expandafter\dotextmodediscretionary + \fi} + +%D The next piece of code is a torture test for this previous +%D macro. The \type {\relax} before the \type {\ifmmode} is +%D needed because of the alignment scanner (in \ETEX\ this +%D problem is not present because there a protected macro is +%D not expanded. Thanks to Tobias Burnus for providing this +%D example. +%D +%D \startformule +%D \left|f(x_n)-{1\over2}\right| = +%D {\cases{|{1\over2}-x_n| &for $0\le x_n < {1\over2}$\cr +%D |x_n-{1\over2}| &for ${1\over2}<x_n\le1$ \cr}} +%D \stopformule + +%D \macros +%D {defineactivecharacter} +%D +%D In \type {lang-ger.tex} we define some language specific +%D commands for german input, like: +%D +%D \starttyping +%D \startlanguagespecifics[de] +%D \installcompoundcharacter "a {\moveaccent{-.1ex}\"a\midworddiscretionary} +%D \stoplanguagespecifics +%D \stoptyping +%D +%D Occasionally we have to redefine such an active character, +%D like in: +%D +%D \starttyping +%D \startencoding[pdfdoc] +%D \startlanguagespecifics[de] +%D \defineactivecharacter " {\"} +%D \stoplanguagespecifics +%D \stopencoding +%D \stoptyping +%D +%D Here is the command we used: + +\def\defineactivecharacter #1 #2% + {\catcode`#1=\@@active + \scratchcounter=\the\uccode`~ + \uccode`~=`#1\relax + \def\next{#2}% + \uppercase{\let~\next}% + \uccode`~=\scratchcounter} + +%D Although adapting character codes and making characters +%D active can interfere with other features of macropackages, +%D normally there should be no problems with things like: +%D +%D \starttypen +%D \installdiscretionary || + +%D \installdiscretionary ++ = +%D \stoptypen +%D +%D The real work is done by the next set of macros. We have +%D to use a double \type{\futurelet} because we have to take +%D following characters into account. + +\def\dotextmodediscretionary#1% + {\bgroup + \def\dodotextmodediscretionary##1#1% + {\def\betweendiscretionary{##1}% + \futurelet\nextnext\dododotextmodediscretionary}% + \let\discretionarycommand=#1% + \def\textmodediscretionary{\getvalue{textmodediscretionary\string#1}}% + \futurelet\next\dodotextmodediscretionary} + +\def\dododotextmodediscretionary% + {\let\nextnextnext=\egroup + \ifx\discretionarycommand\next + \checkafterdiscretionary + \bgroup + \checkbeforediscretionary + \prewordbreak\hbox{\textmodediscretionary\nextnext}\allowbreak + \egroup + \else\ifx=\next + \prewordbreak\textmodediscretionary + \else\ifx~\next + \prewordbreak\discretionary{-}{}{\thinspace}\postwordbreak + \else\ifx_\next + \prewordbreak\discretionary{\textmodediscretionary} + {\textmodediscretionary}{\textmodediscretionary}\prewordbreak + \else\ifx(\next + \ifdim\lastskip>\!!zeropoint\relax + (\prewordbreak + \else + \prewordbreak\discretionary{}{(-}{(}\prewordbreak + \fi + \else\ifx)\next + \ifx\nextnext\blankspace + \prewordbreak)\relax + \else + \prewordbreak\discretionary{-)}{}{)}\prewordbreak + \fi + \else\ifx'\next + \prewordbreak\discretionary{-}{}{'}\postwordbreak + \else\ifx<\next + \beginofsubsentence\prewordbreak\beginofsubsentencespacing + \else\ifnum\uccode`>=\nextuccode + \endofsubsentencespacing\prewordbreak\endofsubsentence + \else + \checkafterdiscretionary + \bgroup + \checkbeforediscretionary + %\prewordbreak\hbox{\betweendiscretionary\nextnext}\allowbreak + \prewordbreak + \discretionary{\hbox{\betweendiscretionary}}{}{\hbox{\betweendiscretionary}}% + \postwordbreak + \egroup + \fi\fi\fi\fi\fi\fi\fi\fi\fi + \nextnextnext} + +\def\checkbeforediscretionary% + {\setbox0=\lastbox + \ifdim\wd0=\!!zeropoint + \let\postwordbreak=\prewordbreak + \fi + \box0\relax} + +\def\checkafterdiscretionary% + {\ifx,\nextnext + \def\nextnextnext{\afterassignment\egroup\let\next=}% + \else + \let\nextnext=\relax + \fi} + +%D The macro \type{\checkbeforediscretionary} takes care of +%D loners like \type{||word}, while it counterpart +%D \type{\checkafterdiscretionary} is responsible for handling +%D the comma. + +%D \macros +%D {beginofsubsentencespacing,endofsubsentencespacing} +%D +%D In the previous macros we provided two hooks which can be +%D used to support nested sub||sentences. In \CONTEXT\ these +%D hooks are used to insert a small space when needed. + +\let\beginofsubsentencespacing=\relax +\let\endofsubsentencespacing =\relax + +%D Before we show some more tricky alternative, we first install +%D the mechanism: + +\installdiscretionaries || \compoundhyphen + +%D \macros +%D {fakecompoundhyphen} +%D +%D In headers and footers as well as in active pieces of text +%D we need a dirty hack. Try to imagine what is needed to +%D savely break the next text across a line and at the same +%D time make the words interactive. +%D +%D \starttypen +%D \goto{Some||Long||Word} +%D \stoptypen + +\def\currentspaceskip% + {\fontdimen2\font\!!plus\fontdimen3\font\!!minus\fontdimen4\font\relax} + +\def\fakecompoundhyphen% + {\def|##1|{\compoundhyphen\nobreak\hskip-\currentspaceskip\allowbreak}} + +%D One of the drawbacks of this mechanism is that characters can +%D be made active afterwards. The next alternative can be used +%D in such situations. This time we don't compare the arguments +%D directly but use the \type{\uccode}'s instead. \TEX\ +%D initializes these codes of the alphabetics glyphs to their +%D uppercase counterparts. Normally the other characters remain +%D zero. If so, we can use the \type{\uccode} as a signal. + +%D \macros +%D {enableactivediscretionaries} +%D +%D The more advanced mechanism is activated by calling: +%D +%D \starttypen +%D \enableactivediscretionaries +%D \stoptypen +%D +%D which is defined as: + +\def\enableactivediscretionaries% + {\uccode`'=`'\relax \uccode`~=`~\relax \uccode`_=`_\relax + \uccode`(=`(\relax \uccode`)=`)\relax \uccode`==`=\relax + \uccode`<=`<\relax \uccode`>=`>\relax + \let\dotextmodediscretionary = \activedotextmodediscretionary + \let\dododotextmodediscretionary = \activedododotextmodediscretionary} + +%D We only have to redefine two macros. While saving the +%D \type{\uccode} in a macro we have to take care of empty +%D arguments, like in \type{||}. + +\def\activedotextmodediscretionary#1% + {\bgroup + \def\dodotextmodediscretionary##1#1% + {\def\betweendiscretionary{##1}% + \def\nextuccode####1####2\relax% + {\ifcat\noexpand####1\noexpand\relax + \edef\nextuccode{0}% + \else + \edef\nextuccode{\the\uccode`####1}% + \fi}% + \nextuccode##1@\relax + \futurelet\nextnext\dododotextmodediscretionary}% + \let\discretionarycommand=#1% + \def\textmodediscretionary{\getvalue{textmodediscretionary\string#1}}% + \futurelet\next\dodotextmodediscretionary} + +%D This time we use \type{\ifnum}: + +\def\activedododotextmodediscretionary% + {\let\nextnextnext=\egroup + \ifx\discretionarycommand\next + \checkafterdiscretionary + \bgroup + \checkbeforediscretionary + \prewordbreak\hbox{\textmodediscretionary\nextnext}\allowbreak + \egroup + \else\ifnum\uccode`==\nextuccode + \prewordbreak\textmodediscretionary + \else\ifnum\uccode`~=\nextuccode + \prewordbreak\discretionary{-}{}{\thinspace}\postwordbreak + \else\ifnum\uccode`_=\nextuccode + \prewordbreak\discretionary{\textmodediscretionary} + {\textmodediscretionary}{\textmodediscretionary}\prewordbreak + \else\ifnum\uccode`(=\nextuccode + \ifdim\lastskip>\!!zeropoint\relax + (\prewordbreak + \else + \prewordbreak\discretionary{}{(-}{(}\prewordbreak + \fi + \else\ifnum\uccode`)=\nextuccode + \ifx\nextnext\blankspace + \prewordbreak)\relax + \else + \prewordbreak\discretionary{-)}{}{)}\prewordbreak + \fi + \else\ifnum\uccode`'=\nextuccode + \prewordbreak\discretionary{-}{}{'}\postwordbreak + \else\ifnum\uccode`<=\nextuccode + \beginofsubsentence\prewordbreak\beginofsubsentencespacing + \else\ifnum\uccode`>=\nextuccode + \endofsubsentencespacing\prewordbreak\endofsubsentence + \else + \checkafterdiscretionary + \bgroup + \checkbeforediscretionary + %\prewordbreak\hbox{\betweendiscretionary\nextnext}\allowbreak + \prewordbreak + \discretionary{\hbox{\betweendiscretionary}}{}{\hbox{\betweendiscretionary}}% + \postwordbreak + \egroup + \fi\fi\fi\fi\fi\fi\fi\fi\fi + \nextnextnext} + +%D Now we can safely do things like: \enableactivediscretionaries +%D +%D \starttypen +%D \catcode`<=\@@active \def<{hello there} +%D \catcode`>=\@@active \def>{hello there} +%D \catcode`(=\@@active \def({hello there} +%D \catcode`)=\@@active \def){hello there} +%D \stoptypen +%D +%D In normal day||to||day production of texts this kind of +%D activation is seldom used.\voetnoot{In the \CONTEXT\ manual +%D the \type{<} and \type{>} are made active and used for some +%D cross||reference trickery.} If so, we have to take care of +%D the math mode explicitly, just like we did when making +%D \type{|} active. It can be confusing too, especially when we +%D load macropackages afterwards that make use of \type{<} in +%D \type{\ifnum} or \type{\ifdim} statements. + +%D \macros +%D {installcompoundcharacter} +%D +%D When Tobias Burnus started translating the dutch manual of +%D \PPCHTEX\ into german, he suggested to let \CONTEXT\ support +%D the \type{german.sty} method of handling compound +%D characters, especially the umlaut. This package is meant for +%D use with \PLAIN\ \TEX\ as well as \LATEX. +%D +%D I decided to implement compound character support as +%D versatile as possible. As a result one can define his own +%D compound character support, like: +%D +%D \starttypen +%D \installcompoundcharacter "a {\"a} +%D \installcompoundcharacter "e {\"e} +%D \installcompoundcharacter "i {\"i} +%D \installcompoundcharacter "u {\"u} +%D \installcompoundcharacter "o {\"o} +%D \installcompoundcharacter "s {\SS} +%D \stoptypen +%D +%D or even +%D +%D \starttypen +%D \installcompoundcharacter "ck {\discretionary {k-}{k}{ck}} +%D \installcompoundcharacter "ff {\discretionary{ff-}{f}{ff}} +%D \stoptypen +%D +%D The support is not limited to alphabetic characters, so the +%D next definition is also valid. +%D +%D \starttypen +%D \installcompoundcharacter ". {.\doifnextcharelse{\spacetoken}{}{\kern.125em}} +%D \stoptypen +%D +%D The implementation looks familiar and uses the same tricks as +%D mentioned earlier in this module. We take care of two +%D arguments, which complicates things a bit. + +\def\@nc@{@nc@} % normal character +\def\@cc@{@cc@} % compound character +\def\@cs@{@cs@} % compound characters + +\def\installcompoundcharacter #1#2#3 #4% {{#4}} keeps move local + {\setvalue{\@nc@\string#1}{\char`#1}% + \def\!!stringa{#3}% + \ifx\!!stringa\empty + \setvalue{\@cc@\string#1\string#2}{{#4}}% + \else + \setvalue{\@cs@\string#1\string#2\string#3}{{#4}}% + \fi + \catcode`#1=\@@active + \scratchcounter=\the\uccode`~ + \uccode`~=`#1 + \uppercase{\unexpanded\def~{\handlecompoundcharacter~}}% + \uccode`~=\scratchcounter} + +%D In handling the compound characters we have to take care of +%D \type{\bgroup} and \type{\egroup} tokens, so we end up with +%D a multi||step interpretation macro. We look ahead for a +%D \type{\bgroup}, \type{\egroup} or \type{\blankspace}. Being +%D no user of this mechanism, the credits for testing them goes +%D to Tobias Burnus, the first german user of \CONTEXT. +%D +%D We define these macros as \type{\long} because we can +%D expect \type{\par} tokens. We need to look into the future +%D with \type{\futurelet} to prevent spaces from +%D disappearing. + +\def\handlecompoundcharacter#1% + {\def\dohandlecompoundcharacter% + {\ifx\next\bgroup + %\def\next{\dodohandlecompoundcharacter#1}% % handle "{ee} -> \"ee + %\let\next\relax % forget "{ee} -> ee + \def\next{\handlecompoundcharacterone#1}% % ignore "{ee} -> "ee + \else\ifx\next\egroup + \let\next\relax + \else\ifx\next\blankspace + %\let\next\relax + \def\next{\getvalue{\@nc@\string#1}}% better + \else + \def\next{\dodohandlecompoundcharacter#1}% + \fi\fi\fi + \next}% + \futurelet\next\dohandlecompoundcharacter} + +\def\dodohandlecompoundcharacter#1#2% + {\def\dododohandlecompoundcharacter% Keep it here and + {\ifx\next\bgroup % preserve spaces! + \def\next{\handlecompoundcharacterone#1#2}% + \else\ifx\next\egroup + \def\next{\handlecompoundcharacterone#1#2}% + \else\ifx\next\blankspace + \def\next{\handlecompoundcharacterone#1#2}% + \else + \def\next{\handlecompoundcharactertwo#1#2}% + \fi\fi\fi + \next}% + \futurelet\next\dododohandlecompoundcharacter} + +%D Besides taken care of the grouping and space tokens, we have +%D to deal with three situations. First we look if the next +%D character equals the first one, if so, then we just insert +%D the original. Next we look if indeed a compound character is +%D defined. We either execute the compound character or just +%D insert the first. So we have +%D +%D \starttypen +%D <key><key> <key><known> <key><unknown> +%D \stoptypen +%D +%D In later modules we will see how these commands are used. + +\beginTEX + +\long\def\handlecompoundcharacterone#1#2% + {\ifx#1#2% + \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}}% + \else\expandafter\ifx\csname\@cc@\string#1\string#2\endcsname\relax + \def\next{\getvalue{\@nc@\string#1}#2}% + \else + \def\next{\getvalue{\@cc@\string#1\string#2}}% + \fi\fi + \next} + +\long\def\handlecompoundcharactertwo#1#2#3% + {\ifx#1#2% + \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}#3}% + \else\@EA\ifx\csname\@cs@\string#1\string#2\string#3\endcsname\relax + \expandafter\ifx\csname\@cc@\string#1\string#2\endcsname\relax + \def\next{\getvalue{\@nc@\string#1}#2#3}% + \else + \def\next{\getvalue{\@cc@\string#1\string#2}#3}% + \fi + \else + \def\next{\getvalue{\@cs@\string#1\string#2\string#3}}% + \fi\fi + \next} + +\endTEX + +\beginETEX \ifcsname + +\long\def\handlecompoundcharacterone#1#2% + {\ifx#1#2% + \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}}% + \else\ifcsname\@cc@\string#1\string#2\endcsname + \def\next{\getvalue{\@cc@\string#1\string#2}}% + \else + \def\next{\getvalue{\@nc@\string#1}#2}% + \fi\fi + \next} + +\long\def\handlecompoundcharactertwo#1#2#3% + {\ifx#1#2% + \def\next{\getvalue{\@nc@\string#1}\getvalue{\@nc@\string#2}#3}% + \else\ifcsname\@cs@\string#1\string#2\string#3\endcsname + \def\next{\getvalue{\@cs@\string#1\string#2\string#3}}% + \else\ifcsname\@cc@\string#1\string#2\endcsname + \def\next{\getvalue{\@cc@\string#1\string#2}#3}% + \else + \def\next{\getvalue{\@nc@\string#1}#2#3}% + \fi\fi\fi + \next} + +\endETEX + +%D \macros +%D {midworddiscretionary} +%D +%D If needed, one can add a discretionary hyphen using \type +%D {\midworddiscretionary}. This macro does the same as +%D \PLAIN\ \TEX's \type {\-}, but, like the ones implemented +%D earlier, this one also looks ahead for spaces and grouping +%D tokens. + +\def\domidworddiscretionary% + {\ifx\next\blankspace\else + \ifx\next\bgroup \else + \ifx\next\egroup \else + \discretionary{-}{}{}% + \fi\fi\fi} + +\def\midworddiscretionary% + {\futurelet\next\domidworddiscretionary} + +%D \macros +%D {hyphenatedurl} +%D +%D For those who want to put full \URL's in a text, we offer +%D +%D \startbuffer +%D \hyphenatedurl{http://optimist.optimist/optimist/optimist.optimist#optimist} +%D \stopbuffer +%D +%D \typebuffer +%D +%D which breaks at the appropriate places. Watch the \type{#} +%D hack. +%D +%D When passed as argument, lik ein \type {\goto}, one needs +%D to substitute a \type {\\} for each \type{#}. +%D +%D \startbuffer +%D \hyphenatedurl{http://this.is.a.rather/strange/reference#indeed} +%D \stopbuffer +%D +%D \typebuffer + +\ifx\\\undefined \let\\\crlf \fi + +\chardef\urlsplitmode=1 + +% 0 => don't split +% 1 => . : na, rest voor +% 2 => alles na +% 3 => alles voor + +\unexpanded\def\hyphenatedurl#1% + {\bgroup + \obeyhyphens + \def\splitbefore##1% + {\setbox\scratchbox=\hbox{##1{}{}}% + \ifcase\urlsplitmode + \box\scratchbox + \or + \postwordbreak\box\scratchbox\prewordbreak + \or + \prewordbreak\discretionary{\box\scratchbox}{}{\box\scratchbox}\prewordbreak + \else + \postwordbreak\box\scratchbox\prewordbreak + \fi}% + \def\splitafter##1% + {\ifcase\urlsplitmode + ##1% + \or + \prewordbreak\discretionary{##1}{}{##1}\prewordbreak + \or + \prewordbreak\discretionary{##1}{}{##1}\prewordbreak + \else + \prewordbreak\discretionary{}{##1}{##1}\prewordbreak + \fi}% + \def\flushurl% + {\savedurl\let\savedurl\empty}% + \def\\% + {\spliturl\#}% + \let~\~% + \let\savedurl\empty + \handletokens#1\with\scanurl + \egroup} + +\bgroup +\catcode`\#=12\gdef\hashletter {#} +\catcode`\_=12\gdef\underscoreletter {_} +\catcode`\~=12\gdef\tildeletter {~} +\catcode`\%=12\gdef\percentletter {%} +\catcode`\?=12\gdef\questionmarkletter{?} +\catcode`\@=12\gdef\atletter {@} +\egroup + +\def\scanurl#1% + {\ifx#1\~% + \flushurl\splitbefore{\~{}}% + \else\ifx#1\#% + \flushurl\splitbefore\#% + \else\ifx#1\&% + \flushurl\splitbefore\&% + \else\ifx#1\%% + \flushurl\splitbefore\%% + \else\ifx#1\_% + \flushurl\splitbefore\_% + \else\if\noexpand#1\relax + #1% + \else\ifnum\catcode`#1=8 + \flushurl\splitbefore\_% + \else\ifnum\catcode`#1=6 + \flushurl\splitbefore\#% + \else\if#1\tildeletter + \flushurl\splitbefore\~% + \else\if#1\percentletter + \flushurl\splitbefore\%% + \else\if#1\underscoreletter + \flushurl\splitbefore\_% + \else\if#1\questionmarkletter + \flushurl\splitafter\questionmarkletter + \else\if#1\atletter + \flushurl\splitafter\atletter + \else\if#1+% + \flushurl\splitafter+% + \else\if#1:% + \flushurl\splitafter:% + \else\if#1.% + \flushurl\splitafter.% + \else\if#1/% + \edef\savedurl{\savedurl/}% + \else + \ifx\savedurl\empty\else + \splitbefore\savedurl + \let\savedurl\empty + \fi + #1% + \fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi} + +%D \macros +%D {hyphenatedfile} +%D +%D For the moment we treat filenames in a similar way, +%D +%D \starttypen +%D \hyphenatedfile{here/there/filename.suffix} +%D \stoptypen + +\let\hyphenatedfile\hyphenatedurl + +\protect + +\endinput |