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+%D \module
+%D [ file=core-con,
+%D version=1997.26.08,
+%D title=\CONTEXT\ Core Macros,
+%D subtitle=Conversion,
+%D author=Hans Hagen,
+%D date=\currentdate,
+%D copyright={PRAGMA ADE \& \CONTEXT\ Development Team}]
+%C
+%C This module is part of the \CONTEXT\ macro||package and is
+%C therefore copyrighted by \PRAGMA. See mreadme.pdf for
+%C details.
+
+\writestatus{loading}{ConTeXt Core Macros / Conversion}
+
+\unprotect
+
+\ifx\currentlanguage\undefined \let\currentlanguage\empty \fi
+\ifx\labeltext \undefined \let\labeltext\firstofoneargument \fi
+
+%D This module deals with all kind of conversions from numbers
+%D and dates. I considered splitting this module in a support
+%D one and a core one, but to keep things simple as well as
+%D preserve the overview, I decided against splitting.
+
+\let\spr\firstofoneargument % separator
+\let\stp\firstofoneargument % stopper
+
+% cleaner, some day:
+%
+% \def\isolateseparators % etex only, even works with list separator overloading
+% {\unexpanded\def\spr##1{{##1}}%
+% \unexpanded\def\stp##1{{##1}}}
+
+% needed for arab :
+
+\def\isolateseparators % even works with list separator overloading
+ {\def\spr##1{{##1}}%
+ \def\stp##1{{##1}}}
+
+%D \macros
+%D {numbers}
+%D
+%D First we deal with the dummy conversion of numbers using the
+%D \TEX\ primitive \type{\number}. The uppercase alternative is
+%D only there for compatibility with the other conversion
+%D macros. We could do without \type{#1} but this way we get
+%D rid of unwanted braces. For the savety we also define a
+%D non||sence uppercase alternative.
+%D
+%D \showsetup{numbers}
+%D
+%D \starttyping
+%D \def\numbers#1{\number#1}
+%D \def\Numbers#1{\number#1}
+%D \stoptyping
+%D
+%D Due to read ahead, as in \type{[\pagenumber\space]} the space will
+%D disappear, unless we use:
+
+\def\numbers#1{\purenumber{#1}}
+\def\Numbers#1{\purenumber{#1}}
+
+%D \macros
+%D {romannumerals,Romannumerals}
+%D
+%D \TEX\ the program uses a rather tricky conversion from
+%D numbers to their roman counterparts. This conversion could
+%D of course be programmed in \TEX\ itself, but I guess Knuth
+%D found the programming trick worth presenting.
+%D
+%D \showsetup{romannumerals}
+%D \showsetup{Romannumerals}
+
+%D When upcasing the result, we just follow the text book rules
+%D of expansion. Later on we'll see some more uppercase tricks.
+
+\def\romannumerals#1%
+ {\romannumeral#1}
+
+%D For some years we had \unknown
+%D
+%D \starttyping
+%D \def\Romannumerals#1%
+%D {\uppercase\expandafter{\romannumeral#1}}
+%D \stoptyping
+%D
+%D \unknown but we need to be fully expandable in order to get
+%D the utility output file right, so now we have the following
+%D solution. It was Patrick Gundlach who first noticed this
+%D ommision.
+
+\def\Romannumerals#1%
+ {\expandafter\doRomannumerals\number#1\relax}
+
+\def\doRomannumerals#1#2\relax % spaces after ifcase prevent \relax
+ {\ifnum#1#2<10
+ \ifcase0#1#2 \or I\or II\or III\or IV\or V\or VI\or VII\or VIII\or IX\fi
+ \else\ifnum#1#2<100
+ \ifcase0#1 \or X\or XX\or XXX\or XL\or L\or LX\or LXX\or LXXX\or XC\fi
+ \doRomannumerals#2\relax
+ \else\ifnum#1#2<1000
+ \ifcase0#1 \or C\or CC\or CCC\or CD\or D\or DC\or DCC\or DCCC\or CM\fi
+ \doRomannumerals#2\relax
+ \else\ifnum#1#2<4000
+ \ifcase0#1 \or M\or MM\or MMM\fi
+ \doRomannumerals#2\relax
+ \else
+ \uppercase\expandafter{\romannumeral#1#2}%
+ \fi\fi\fi\fi}
+
+%D \macros
+%D {character,Character}
+%D
+%D Converting a number into a character can of course only
+%D be done with numbers less or equal to~26. At the cost of
+%D much more macros a faster conversion is possible, using:
+%D
+%D \starttyping
+%D \setvalue{char1}{a} \def\character#1{\getvalue{char#1}}
+%D \stoptyping
+%D
+%D But we prefer a simpel \type{\case}.
+%D
+%D \showsetup{character}
+%D \showsetup{Character}
+
+\def\unknowncharacter{-} % else in lists \relax
+
+%D Big case statements but pretty fast:
+
+\def\character#1%
+ {\ifcase#1\unknowncharacter
+ \or a\or b\or c\or d\or e\or f\or g\or h\or i\or j\or k\or l\or m%
+ \or n\or o\or p\or q\or r\or s\or t\or u\or v\or w\or x\or y\or z%
+ \else
+ \unknowncharacter
+ \fi}
+
+\def\Character#1%
+ {\ifcase#1\unknowncharacter
+ \or A\or B\or C\or D\or E\or F\or G\or H\or I\or J\or K\or L\or M%
+ \or N\or O\or P\or Q\or R\or S\or T\or U\or V\or W\or X\or Y\or Z%
+ \else
+ \unknowncharacter
+ \fi}
+
+%D \macros
+%D {characters,Characters}
+%D
+%D Converting large numbers is supported by the next two
+%D macros. This time we just count on: $\cdots$~x, y, z, aa,
+%D ab, ac~$\cdots$.
+%D
+%D \showsetup{characters}
+%D \showsetup{Characters}
+
+%D The fully expandable alternative:
+
+\def\dodoconvertcharacters#1#2#3%
+ {\ifcase#3\else
+ \ifnum#3>#1
+ \expandafter\doconvertcharacters\expandafter#2\expandafter{\the\numexpr(#3+12)/#1-1\relax}%
+ \expandafter#2\expandafter{\the\numexpr#3-((#3+12)/#1-1)*#1\relax}%
+ \else
+ \expandafter#2\expandafter{\number#3}%
+ \fi
+ \fi}
+
+\def\doconvertcharacters{\dodoconvertcharacters{26}}
+
+\def\characters{\doconvertcharacters\character}
+\def\Characters{\doconvertcharacters\Character}
+
+%D \macros
+%D {greeknumerals,Greeknumerals}
+%D
+%D Why should we only honour the romans, and not the greek?
+
+\def\greeknumerals#1%
+ {% no longer needed: \mathematics
+ {\ifcase#1\unknowncharacter\or
+ \alpha \or \beta \or \gamma \or \delta \or
+ \varepsilon \or \zeta \or \eta \or \theta \or
+ \iota \or \kappa \or \lambda \or \mu \or
+ \nu \or \xi \or \omicron \or \pi \or
+ \varrho \or \sigma \or \tau \or \upsilon \or
+ \phi \or \chi \or \psi \or \omega
+ \else
+ \unknowncharacter
+ \fi}}
+
+\def\Greeknumerals#1%
+ {% no longer needed: \mathematics
+ {\ifcase#1\unknowncharacter \or
+ \Alpha \or \Beta \or \Gamma \or \Delta \or
+ \Epsilon \or \Zeta \or \Eta \or \Theta \or
+ \Iota \or \Kappa \or \Lambda \or \Mu \or
+ \Nu \or \Xi \or \Omicron \or \Pi \or
+ \Rho \or \Sigma \or \Tau \or \Upsilon \or
+ \Phi \or \Xi \or \Psi \or \Omega
+ \else
+ \unknowncharacter
+ \fi}}
+
+%D \macros
+%D {oldstylenumerals,oldstyleromannumerals}
+%D
+%D These conversions are dedicated to Frans Goddijn.
+
+\unexpanded\def\oldstylenumerals#1%
+ {{\os\number#1}}
+
+\unexpanded\def\oldstyleromannumerals#1%
+ {{\leftrulefalse\rightrulefalse\ss\txx\boxrulewidth.15ex
+ \ruledhbox spread .15em{\hss\uppercased{\romannumerals{#1}}\hss}}}
+
+%D \macros
+%D {protectconversion}
+%D
+%D The previous two commands are not robust enough to be
+%D passed to \type{\write} en \type{\message}. That's why we
+%D introduce:
+
+\def\protectconversion
+ {\def\doconvertcharacters##1{##1}} % was \relax
+ %{\def\doconvertcharacters##1{\ifcase0##1 0\else##1\fi}} more save
+
+%D \macros
+%D {normaltime,normalyear,normalmonth,normalday}
+%D
+%D The last part of this module is dedicated to converting
+%D dates. Because we want to use as meaningful commands as
+%D possible, and because \TEX\ already uses up some of those,
+%D we save the original meanings.
+
+\savenormalmeaning\time
+\savenormalmeaning\year
+\savenormalmeaning\month
+\savenormalmeaning\day
+
+%D \macros
+%D {month,MONTH}
+%D
+%D Converting the month number into a month name is done
+%D using a case statement, abstact values and the label
+%D mechanism. This way users can easily redefine a label from
+%D for instance german into austrian.
+%D
+%D \starttyping
+%D \setuplabeltext [de] [january=J\"anner]
+%D \stoptyping
+%D
+%D Anyhow, the conversion looks like:
+
+\def\domonthtag#1%
+ {\ifcase#1%
+ \or \v!january \or \v!february \or \v!march \or \v!april
+ \or \v!may \or \v!june \or \v!july \or \v!august
+ \or \v!september \or \v!october \or \v!november \or \v!december
+ \else
+ \v!unknown
+ \fi}
+
+\def\doconvertmonthlong #1{\labeltext{\domonthtag{#1}}}
+\def\doconvertmonthshort#1{\labeltext{\domonthtag{#1}:\s!mnem}}
+
+\let\doconvertmonth\doconvertmonthlong
+
+%D We redefine the \TEX\ primitive \type{\month} as:
+%D
+%D \showsetup{month}
+%D \showsetup{MONTH}
+
+\def\monthlong {\doconvertmonthlong}
+\def\monthshort{\doconvertmonthshort}
+\def\month {\doconvertmonth}
+
+\def\MONTH #1{{\let\labeltext\LABELTEXT\month {#1}}}
+\def\MONTHLONG #1{{\let\labeltext\LABELTEXT\monthlong {#1}}}
+\def\MONTHSHORT#1{{\let\labeltext\LABELTEXT\monthshort{#1}}}
+
+%D We never explicitly needed this, but Tobias Burnus pointed
+%D out that it would be handy to convert to the day of the
+%D week. In doing so, we have to calculate the total number of
+%D days, taking leapyears into account. For those who are
+%D curious:
+%D
+%D \startitemize[packed]
+%D \item years that can be divided by 4 are leapyears
+%D \item exept years that can be divided by 100
+%D \item unless years can be divided by 400
+%D \stopitemize
+%D
+%D This makes the year 1900 into a normal year and 1996 and
+%D 2000 into leap years, right? Well, converting to string
+%D looks familiar:
+
+\def\doconvertday#1%
+ {\labeltext
+ {\ifcase#1
+ \or \v!sunday \or \v!monday \or \v!tuesday \or \v!wednesday
+ \or \v!thursday \or \v!friday \or \v!saturday \fi}}
+
+%D \macros
+%D {getdayoftheweek, dayoftheweek}
+%D
+%D The conversion algoritm is an old one and a translation from
+%D a procedure written in MODULA~2 back in the 80's. I finaly
+%D found the 4--100-400 rules in some enclopedia. Look at this
+%D messy low level routine that takes the day, month and year
+%D as arguments:
+
+\newcount\normalweekday
+
+\def\getdayoftheweek#1#2#3%
+ {\bgroup
+ \!!counta#3\relax
+ \advance\!!counta \minusone
+ \!!countb\!!counta
+ \multiply\!!countb 365
+ \advance\!!countb \ifcase#2\relax
+ 0 \or 0 \or 31 \or 59 \or 90 \or120 \or151 \or
+ 181 \or212 \or243 \or273 \or304 \or334 \or365 \fi
+ \advance\!!countb #1\relax
+ \ifnum#2>2
+ \doifleapyearelse{#3}{\advance\!!countb 1}{}\relax
+ \fi
+ \!!countc\!!counta
+ \dosetdivision\!!countc4\!!countc
+ \advance\!!countb \!!countc
+ \!!countc\!!counta
+ \dosetdivision\!!countc{100}\!!countc
+ \advance\!!countb -\!!countc
+ \!!countc\!!counta
+ \dosetdivision\!!countc{400}\!!countc
+ \advance\!!countb \!!countc
+ \dosetmodulo\!!countb7\!!countb
+ \advance\!!countb \plusone
+ \@EA\egroup\@EA\normalweekday\the\!!countb\relax}
+
+\def\dayoftheweek#1#2#3%
+ {\getdayoftheweek{#1}{#2}{#3}\doconvertday{\normalweekday}}
+
+%D Using this macro in
+%D
+%D \startbuffer
+%D monday: \dayoftheweek {4} {5} {1992}
+%D friday: \dayoftheweek {16} {6} {1995}
+%D monday: \dayoftheweek {25} {8} {1997}
+%D saturday: \dayoftheweek {30} {8} {1997}
+%D tuesday: \dayoftheweek {2} {1} {1996}
+%D tuesday: \dayoftheweek {7} {1} {1997}
+%D tuesday: \dayoftheweek {13} {1} {1998}
+%D friday: \dayoftheweek {1} {1} {2000}
+%D \stopbuffer
+%D
+%D \typebuffer
+%D
+%D gives
+%D
+%D \startvoorbeeld
+%D \startlines
+%D \getbuffer
+%D \stoplines
+%D \stopvoorbeeld
+%D
+%D The macro \type {\getdayoftheweek} can be used to calculate
+%D the number \type {\normalweekday}.
+
+%D \macros
+%D {weekday,WEEKDAY}
+%D
+%D The first one is sort of redundant. It takes the day
+%D number argument.
+%D
+%D \showsetup{weekday}
+%D \showsetup{WEEKDAY}
+
+\def\weekday
+ {\doconvertday}
+
+\def\WEEKDAY#1%
+ {{\let\labeltext\LABELTEXT\doconvertday{#1}}}
+
+%D \macros
+%D {weekoftheday}
+%D
+%D {\em not yet implemented:}
+%D
+%D \starttyping
+%D \def\weekoftheday#1#2#3%
+%D {}
+%D \stoptyping
+
+%D \macros
+%D {doifleapyearelse,
+%D getdayspermonth}
+%D
+%D Sometimes we need to know if we're dealing with a
+%D leapyear, so here is a testmacro:
+%D
+%D \starttyping
+%D \doifleapyearelse{year}{yes}{no}
+%D \stoptyping
+%D
+%D An example of its use can be seen in the macro
+%D
+%D \starttyping
+%D \getdayspermonth{year}{month}
+%D \stoptyping
+%D
+%D The number of days is available in the macro \type
+%D {\numberofdays}.
+
+\def\doifleapyearelse#1% #2#3%
+ {\bgroup
+ \!!doneafalse
+ \!!counta#1%
+ \dosetmodulo\!!counta4\!!countb
+ \ifcase\!!countb
+ \dosetmodulo\!!counta{100}\!!countb
+ \ifcase\!!countb \else \!!doneatrue \fi
+ \dosetmodulo\!!counta{400}\!!countb
+ \ifcase\!!countb \!!doneatrue \fi
+ \fi
+ \if!!donea
+ \egroup\@EA\firstoftwoarguments % \def\next{#2}%
+ \else
+ \egroup\@EA\secondoftwoarguments % \def\next{#3}%
+ \fi} % \next}
+
+% untested but cleaner:
+%
+% \def\doifleapyearelse#1% #2#3%
+% {\bgroup
+% \dosetmodulo{#1}{400}\scratchcounter
+% \ifcase\scratchcounter
+% \else
+% \dosetmodulo{#1}{100}\scratchcounter
+% \ifcase\scratchcounter
+% \scratchcounter\plusone
+% \else
+% \dosetmodulo{#1}4\scratchcounter
+% \fi
+% \fi
+% \ifcase\scratchcounter
+% \egroup\@EA\firstoftwoarguments
+% \else
+% \egroup\@EA\secondoftwoarguments
+% \fi}
+
+\def\getdayspermonth#1#2%
+ {\doifleapyearelse{#1}
+ {\def\numberofdays{29}}
+ {\def\numberofdays{28}}%
+ \edef\numberofdays
+ {\ifcase#2 \or31\or\numberofdays\or31\or30\or
+ 31\or30\or31\or31\or30\or31\or30\or31\fi}}
+
+%D \macros
+%D {currentdate, date}
+%D
+%D We use these conversion macros in the date formatting
+%D macro:
+%D
+%D \showsetup{currentdate}
+%D
+%D This macro takes care of proper spacing and delivers for
+%D instance:
+%D
+%D \startbuffer
+%D \currentdate[weekday,day,month,year] % still dutch example
+%D \currentdate[WEEKDAY,day,MONTH,year] % still dutch example
+%D \stopbuffer
+%D
+%D \startvoorbeeld
+%D \startlines
+%D \getbuffer
+%D \stoplines
+%D \stopvoorbeeld
+%D
+%D depending of course on the keywords. Here we gave:
+%D
+%D \typebuffer
+%D
+%D If needed one can also add non||keywords, like in
+%D
+%D \startbuffer
+%D \currentdate[dd,--,mm,--,yy]
+%D \stopbuffer
+%D
+%D \typebuffer
+%D
+%D or typeset: \getbuffer.
+%D
+%D When no argument is passed, the current date is given as
+%D specified per language (using \type{\installlanguage}).
+%D
+%D \showsetup{currentdate}
+%D
+%D \startbuffer
+%D \date
+%D \date[d=12,m=12,y=1998][weekday]
+%D \date[d=12,m=12,y=1998]
+%D \stopbuffer
+%D
+%D We can also typeset arbitrary dates, using the previous
+%D command.
+%D
+%D \typebuffer
+%D
+%D The date is specified by one character keys. When no date
+%D is given, we get the current date.
+%D
+%D \startlines
+%D \getbuffer
+%D \stoplines
+
+\def\kenmerkdatumpatroon{j,mm,dd} % jj,mm,dd changed at januari 1-1-2000
+
+\newsignal\datesignal
+
+\def\dobetweendates
+ {\ifdim\lastskip=\datesignal\relax\else
+ \unskip\space
+ \hskip\datesignal\relax
+ \fi}
+
+\newtoks \everycurrentdate
+
+\def\complexcurrentdate[#1]%
+ {\bgroup
+ \the\everycurrentdate
+ \def\betweendates{\let\betweendates\dobetweendates}%
+ % was \processcommacommandp[#1]\docomplexcurrentdate
+ \safeedef\ascii{\empty#1}% keep encoded chars
+ \@EA\processcommalist\@EA[\ascii]\docomplexcurrentdate
+ \ifdim\lastskip=\datesignal\relax
+ \unskip
+ \fi
+ \egroup}
+
+\def\docomplexcurrentdate#1%
+ {\lowercase{\edef\!!stringa{#1}}% permits usage in \smallcapped
+ \expanded{\processaction[\!!stringa]}% [#1]
+ [ \v!day=>\betweendates\the\normalday,
+ %\v!day+=>\betweendates\ordinaldaynumber\normalday,
+ \v!day+=>\betweendates\convertnumber{\v!day+}\normalday,
+ \v!month=>\betweendates\month\normalmonth,
+ \v!year=>\betweendates\the\normalyear,
+ \v!space=>\unskip\ \hskip\datesignal,% optimization -)
+ \ =>\unskip\ \hskip\datesignal,% optimization -)
+ d=>\convertnumber\v!day\normalday,
+ %d+=>\ordinaldaynumber\normalday,
+ d+=>\convertnumber{\v!day+}\normalday,
+ m=>\convertnumber\v!month\normalmonth,
+ j=>\convertnumber\v!year\normalyear,
+ y=>\convertnumber\v!year\normalyear,
+ w=>\betweendates\dayoftheweek\normalday\normalmonth\normalyear,
+ dd=>\ifnum\normalday >9 \else0\fi\the\normalday,
+ %dd+=>\ordinaldaynumber{\ifnum\normalday >9 \else0\fi\the\normalday},
+ dd+=>\convertnumber{\v!day+}{\ifnum\normalday >9 \else0\fi\the\normalday},
+ mm=>\ifnum\normalmonth>9 \else0\fi\the\normalmonth,
+ jj=>\expandafter\gobbletwoarguments\the\normalyear,
+ yy=>\expandafter\gobbletwoarguments\the\normalyear,
+ \v!weekday=>\betweendates\dayoftheweek\normalday\normalmonth\normalyear,
+ \v!referral=>\expanded{\complexcurrentdate[\kenmerkdatumpatroon]},
+ \s!unknown=>\unskip
+ % #1 and not the lowercased \commalistelement, vietnamese has text
+ % {} because #1 can have comma, like: {\ ,}
+ {#1}%
+ \hskip\datesignal
+ \def\betweendates{\let\betweendates\dobetweendates}]}
+
+\def\simplecurrentdate
+ {\expanded{\complexcurrentdate[\currentdatespecification]}}
+
+\definecomplexorsimple\currentdate
+
+\def\dodate[#1][#2]%
+ {\bgroup
+ \iffirstargument
+ \getparameters[\??da][d=\normalday,m=\normalmonth,y=\normalyear,#1]%
+ \normalday \@@dad\relax
+ \normalmonth\@@dam\relax
+ \normalyear \@@day\relax
+ \ifsecondargument
+ \currentdate[#2]%
+ \else
+ \currentdate
+ \fi
+ \else
+ \currentdate
+ \fi
+ \egroup}
+
+\def\date
+ {\dodoubleempty\dodate}
+
+%D \macros
+%D {currenttime}
+%D
+%D The currenttime is actually the jobtime. You can specify
+%D a pattern similar to the previous date macro using the
+%D keys \type {h}, \type {m} and a separator.
+
+\def\calculatecurrenttime
+ {\dosetdivision\time{60}\scratchcounter
+ \edef\currenthour {\ifnum\scratchcounter<10 0\fi \the\scratchcounter}%
+ \dosetmodulo \time{60}\scratchcounter
+ \edef\currentminute{\ifnum\scratchcounter<10 0\fi \the\scratchcounter}}
+
+\let\currenthour \!!plusone
+\let\currentminute\!!plusone
+
+\def\currenttimespecification{h,:,m}
+
+\def\complexcurrenttime[#1]%
+ {\calculatecurrenttime
+ \processallactionsinset[#1]
+ [h=>\currenthour,m=>\currentminute,\s!unknown=>\commalistelement]}
+
+\def\simplecurrenttime
+ {\expanded{\complexcurrenttime[\currenttimespecification]}}
+
+\definecomplexorsimple\currenttime
+
+%D Because we're dealing with dates, we also introduce a few
+%D day loops:
+%D
+%D \starttyping
+%D \processmonth{year}{month}{command}
+%D \processyear{year}{command}{before}{after}
+%D \stoptyping
+%D
+%D The counters \type {\normalyear}, \type {\normalmonth} and
+%D \type{\normalday} can be used for for date manipulations.
+
+\long\def\processmonth#1#2#3% year month command
+ {\bgroup
+ \getdayspermonth{#1}{#2}%
+ \dostepwiserecurse1\numberofdays1%
+ {\normalyear #1\relax
+ \normalmonth#2\relax
+ \normalday \recurselevel\relax
+ #3}%
+ \egroup}
+
+\def\lastmonth{12} % can be set to e.g. 1 when testing
+
+\long\def\processyear#1#2#3#4% year command before after
+ {\bgroup
+ \dorecurse\lastmonth
+ {\normalyear #1\relax
+ \normalmonth\recurselevel\relax
+ #3\processmonth\normalyear\normalmonth{#2}#4}%
+ \egroup}
+
+%D \macros
+%D {defineconversion, convertnumber}
+%D
+%D Conversion involves the macros that we implemented earlier
+%D in this module.
+%D
+%D \showsetup{defineconversion}
+%D \showsetup{convertnumber}
+%D
+%D We can feed this command with conversion macros as well as
+%D a set of conversion symbols. Both need a bit different
+%D treatment.
+%D
+%D \starttyping
+%D \defineconversion [roman] [\romannumerals]
+%D \defineconversion [set 1] [$\star$,$\bullet$,$\ast$]
+%D \stoptyping
+%D
+%D You can define a language dependent conversion with:
+%D
+%D \starttyping
+%D \defineconversion [en] [whatever] [\something]
+%D \stoptyping
+
+% \def\dodefineconversion[#1][#2]%
+% {\ConvertConstantAfter\doifinstringelse{,}{#2}
+% {\scratchcounter=0
+% \def\docommand##1%
+% {\advance\scratchcounter 1
+% \setvalue{\??cv#1\the\scratchcounter}{##1}}%
+% \processcommalist[#2]\docommand
+% \setvalue{\??cv#1}##1{\csname\??cv#1##1\endcsname}}
+% {\setvalue{\??cv#1}{#2}}}
+%
+% \def\defineconversion%
+% {\dodoubleargument\dodefineconversion}
+
+\def\defineconversion
+ {\dotripleempty\dodefineconversion}
+
+\def\dodefineconversion[#1][#2][#3]%
+ {\ifthirdargument
+ \dododefineconversion[#1][#2][#3]%
+ \else
+ \dododefineconversion[][#1][#2]%
+ \fi}
+
+%D \starttyping
+%D \def\dododefineconversion[#1][#2][#3]%
+%D {\ConvertConstantAfter\doifinstringelse{,}{#3}
+%D {\scratchcounter\zerocount
+%D \def\docommand##1%
+%D {\advance\scratchcounter \plusone
+%D \setvalue{\??cv#1#2\the\scratchcounter}{##1}}%
+%D \processcommalist[#3]\docommand
+%D \setvalue{\??cv#1#2}##1{\executeifdefined{\??cv#1#2##1}\unknown}} % catch out-of-range numbers
+%D {\setvalue{\??cv#1#2}{#3}}}
+%D \stoptyping
+
+%D This approach has the disadvantage that when you run out of
+%D symbols you get unknown results. The following implementation
+%D permits overloading of the converter:
+
+\def\dododefineconversion[#1][#2][#3]%
+ {\ConvertConstantAfter\doifinstringelse{,}{#3}
+ {\scratchcounter\zerocount
+ \def\docommand##1%
+ {\advance\scratchcounter \plusone
+ \setvalue{\??cv#1#2\the\scratchcounter}{##1}}%
+ \processcommalist[#3]\docommand
+ \setevalue{\??cv#1#2}##1%
+ {\noexpand\docheckedconversion{#1#2}{\the\scratchcounter}{##1}}}
+ {\setvalue{\??cv#1#2}{#3}}}
+
+\def\docheckedconversion#1#2#3% class maxnumber number
+ {\executeifdefined{\??cv#1#3}\unknown}
+
+%D When Gerben reported problems with footnote numbering per page,
+%D Taco came with the following wrap around solution. So, let's
+%D overload the checked conversion macro:
+
+\def\docheckedconversion#1#2#3% class maxnumber number
+ {\executeifdefined{\??cv#1\modulatednumber{#2}{#3}}\unknown}
+
+%D Taco's modulo code is implemented in the system module
+%D \type {syst-con}.
+
+%D If a conversion is just a font switch then we need to make sure
+%D that the number is indeed end up as number in the input, so we
+%D need to handle the second argument.
+
+\def\convertnumber#1#2%
+ {\csname\??cv
+ \ifcsname\??cv\currentlanguage#1\endcsname
+ \currentlanguage#1%
+ \else\ifcsname\??cv#1\endcsname
+ #1%
+ \else
+ \s!default
+ \fi\fi
+ \endcsname{\number#2}}
+
+\def\doifconversiondefinedelse#1%
+ {\ifcsname\??cv\currentlanguage#1\endcsname
+ \@EA\firstoftwoarguments
+ \else\ifcsname\??cv#1\endcsname
+ \@EAEAEA\firstoftwoarguments
+ \else
+ \@EAEAEA\secondoftwoarguments
+ \fi\fi}
+
+\def\doifelseconversionnumber#1#2% slow but seldom used
+ {\doifdefinedelse{\??cv#1#2}}
+
+%D Handy.
+
+\setvalue{\??cv:\c!n:\v!one }{1}
+\setvalue{\??cv:\c!n:\v!two }{2}
+\setvalue{\??cv:\c!n:\v!three}{3}
+\setvalue{\??cv:\c!n:\v!four }{4}
+\setvalue{\??cv:\c!n:\v!five }{5}
+
+\def\wordtonumber#1#2{\ifcsname\??cv:\c!n:#1\endcsname\csname\??cv:\c!n:#1\endcsname\else#2\fi}
+
+% \defineconversion[ctx][c,o,n,t,e,x,t]
+%
+% \doloop{\doifelseconversionnumber{ctx}{\recurselevel}{[\recurselevel]}{\exitloop}}
+
+\defineconversion [\s!default] [\numbers]
+
+%D As longs as symbols are linked to levels or numbers, we can
+%D also use the conversion mechanism, but in for instance the
+%D itemization macros, we prefer symbols because they can more
+%D easier be (partially) redefined. Symbols are implemented
+%D in another module.
+
+\defineconversion [] [\numbers] % the default conversion
+
+\defineconversion [a] [\characters]
+\defineconversion [A] [\Characters]
+\defineconversion [AK] [\smallcapped\characters]
+\defineconversion [KA] [\smallcapped\characters]
+
+\defineconversion [n] [\numbers]
+\defineconversion [N] [\Numbers]
+\defineconversion [m] [\mediaeval]
+
+\defineconversion [i] [\romannumerals]
+\defineconversion [I] [\Romannumerals]
+\defineconversion [r] [\romannumerals]
+\defineconversion [R] [\Romannumerals]
+\defineconversion [KR] [\smallcapped\romannumerals]
+\defineconversion [RK] [\smallcapped\romannumerals]
+
+\defineconversion [g] [\greeknumerals]
+\defineconversion [G] [\Greeknumerals]
+
+\defineconversion [o] [\oldstylenumerals]
+\defineconversion [O] [\oldstylenumerals]
+\defineconversion [or] [\oldstyleromannumerals]
+
+\defineconversion [\v!character] [\character]
+\defineconversion [\v!Character] [\Character]
+
+\defineconversion [\v!characters] [\characters]
+\defineconversion [\v!Characters] [\Characters]
+
+\defineconversion [\v!numbers] [\numbers]
+\defineconversion [\v!Numbers] [\Numbers]
+\defineconversion [\v!mediaeval] [\mediaeval]
+
+\defineconversion [\v!romannumerals] [\romannumerals]
+\defineconversion [\v!Romannumerals] [\Romannumerals]
+
+\defineconversion [\v!greek] [\greeknumerals]
+\defineconversion [\v!Greek] [\Greeknumerals]
+
+\defineconversion [arabicnumerals] [\arabicnumerals]
+\defineconversion [persiannumerals] [\arabicnumerals]
+
+\defineconversion [month] [\doconvertmonthlong]
+\defineconversion [month:mnem] [\doconvertmonthshort]
+
+% Some bonus ones:
+
+\defineconversion [\v!empty] [\gobbleoneargument]
+\defineconversion [\v!none] [\numbers]
+
+\ifx\symbol\undefined \def\symbol[#1]{#1} \fi % todo
+
+\defineconversion
+ [set 0]
+ [{\symbol[bullet]},
+ {\symbol[dash]},
+ {\symbol[star]},
+ {\symbol[triangle]},
+ {\symbol[circle]},
+ {\symbol[medcircle]},
+ {\symbol[bigcircle]},
+ {\symbol[square]}]
+
+\defineconversion
+ [set 1]
+ [\mathematics{\star},
+ \mathematics{\star\star},
+ \mathematics{\star\star\star},
+ \mathematics{\ddagger},
+ \mathematics{\ddagger\ddagger},
+ \mathematics{\ddagger\ddagger\ddagger},
+ \mathematics{\ast},
+ \mathematics{\ast\ast},
+ \mathematics{\ast\ast\ast}]
+
+\defineconversion
+ [set 2]
+ [\mathematics{*},
+ \mathematics{\dag},
+ \mathematics{\ddag},
+ \mathematics{**},
+ \mathematics{\dag\dag},
+ \mathematics{\ddag\ddag},
+ \mathematics{***},
+ \mathematics{\dag\dag\dag},
+ \mathematics{\ddag\ddag\ddag},
+ \mathematics{****},
+ \mathematics{\dag\dag\dag\dag},
+ \mathematics{\ddag\ddag\ddag\ddag}]
+
+\defineconversion
+ [set 3]
+ [\mathematics{\star},
+ \mathematics{\star\star},
+ \mathematics{\star\star\star},
+ \mathematics{\ddagger},
+ \mathematics{\ddagger\ddagger},
+ \mathematics{\ddagger\ddagger\ddagger},
+ \mathematics{\P},
+ \mathematics{\P\P},
+ \mathematics{\P\P\P},
+ \mathematics{\S},
+ \mathematics{\S\S},
+ \mathematics{\S\S\S},
+ \mathematics{\ast},
+ \mathematics{\ast\ast},
+ \mathematics{\ast\ast\ast}]
+
+%D \macros
+%D {defineconversionvector,conversionnumber} % bad names so no danger for clash
+%D
+%D For Adam and friends \unknown
+%D
+%D \startitemize[persiannummerals]
+%D \item test \item test \item test \item test
+%D \stopitemize
+
+\def\defineconversionvector#1#2% name base
+ {\bgroup
+ % dirty trick
+ \uccode`\*=`\1
+ % plain:
+ % \uccode`\0=\numexpr#2+0\relax \uccode`\1=\numexpr#2+1\relax
+ % \uccode`\2=\numexpr#2+2\relax \uccode`\3=\numexpr#2+3\relax
+ % \uccode`\4=\numexpr#2+4\relax \uccode`\5=\numexpr#2+5\relax
+ % \uccode`\6=\numexpr#2+6\relax \uccode`\7=\numexpr#2+7\relax
+ % \uccode`\8=\numexpr#2+8\relax \uccode`\9=\numexpr#2+9\relax
+ % context:
+ \dostepwiserecurse091{\expandafter\uccode\expandafter`\recurselevel=\numexpr#2+\recurselevel}%
+ % prepared macro
+ \uppercase\expandafter{\expandafter\gdef\csname::cvn::#1::\endcsname##*%
+ {\ifcase##* 0\or1\or2\or3\or4\or5\or6\or7\or8\or9\fi}}%
+ \egroup}
+
+\def\conversionnumber#1#2%
+ {\ifcsname::cvn::#1::\endcsname
+ \expandafter\doconversionnumber\csname::cvn::#1::\expandafter\endcsname\number#2\relax
+ \else
+ \number#2%
+ \fi}
+
+\def\doconversionnumber#1#2%
+ {\ifx#2\relax
+ \expandafter\gobbleoneargument
+ \else
+ #1{#2}%
+ \expandafter\doconversionnumber
+ \fi#1}
+
+% actually mkiii code
+
+\ifnum\texengine=\xetexengine
+
+ \defineconversionvector{arabicnumerals} {"0660}
+ \defineconversionvector{persiannumerals} {"06F0}
+ \defineconversionvector{thainumerals} {"0E50}
+ \defineconversionvector{devanagarinumerals}{"0966}
+ \defineconversionvector{gurmurkhinumerals} {"0A66}
+ \defineconversionvector{gujaratinumerals} {"0AE6}
+ \defineconversionvector{tibetannumerals} {"0F20} % also "half numerals?"
+
+ \defineconversion[arabicnumerals] [\conversionnumber{arabicnumerals}]
+ \defineconversion[persiannumerals] [\conversionnumber{persiannumerals}]
+ \defineconversion[thainumerals] [\conversionnumber{thainumerals}]
+ \defineconversion[devanagarinumerals][\conversionnumber{devanagarinumerals}]
+ \defineconversion[gurmurkhinumerals] [\conversionnumber{gurmurkhinumerals}]
+ \defineconversion[gujaratinumerals] [\conversionnumber{gujaratinumerals}]
+ \defineconversion[tibetannumerals] [\conversionnumber{tibetannumerals}]
+
+\fi
+
+\protect \endinput