syst-con.mkiv / last modification: 2020-01-30 14:16
%D \module
%D   [       file=syst-con,
%D        version=2006.09.16, % real old stuff ... 2000.12.10
%D          title=\CONTEXT\ System Macros,
%D       subtitle=Conversions,
%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.

\registerctxluafile{syst-con}{}

\unprotect

%D \macros{lchexnumber,uchexnumber,lchexnumbers,uchexnumbers}
%D
%D In addition to the uppercase hex conversion, as needed in math families, we
%D occasionally need a lowercase one.

\def\lchexnumber #1{\clf_lchexnumber \numexpr#1\relax}
\def\uchexnumber #1{\clf_uchexnumber \numexpr#1\relax}
\def\lchexnumbers#1{\clf_lchexnumbers\numexpr#1\relax}
\def\uchexnumbers#1{\clf_uchexnumbers\numexpr#1\relax}

\let\hexnumber\uchexnumber

%D \macros{octnumber}
%D
%D For \UNICODE\ remapping purposes, we need octal numbers.

\def\octnumber#1{\clf_octnumber\numexpr#1\relax}

%D \macros{hexstringtonumber,octstringtonumber}
%D
%D This macro converts a two character hexadecimal number into a decimal number,
%D thereby taking care of lowercase characters as well.

\def\hexstringtonumber#1{\clf_hexstringtonumber\numexpr#1\relax}
\def\octstringtonumber#1{\clf_octstringtonumber\numexpr#1\relax}

%D \macros{rawcharacter}
%D
%D This macro can be used to produce proper 8 bit characters that we sometimes need
%D in backends and round||trips.

\def\rawcharacter#1{\clf_rawcharacter\numexpr#1\relax}

%D \macros{twodigits, threedigits}
%D
%D These macros provides two or three digits always:

\def\twodigits  #1{\ifnum             #1<10     0\fi\number#1}
\def\threedigits#1{\ifnum#1<100 \ifnum#1<10 0\fi0\fi\number#1}

%D \macros{modulonumber}
%D
%D In the conversion macros described in \type {core-con} we need a wrap||around
%D method. The following solution is provided by Taco.
%D
%D The \type {modulonumber} macro expands to the mathematical modulo of a positive
%D integer. It is crucial for it's application that this macro is fully exandable.
%D
%D The expression inside the \type {\numexpr} itself is somewhat bizarre because
%D \ETEX\ uses a rounding division instead of truncation. If \ETEX's division would
%D have behaved like \TEX's normal\type {\divide}, then the expression could have
%D been somewhat simpler, like \type {#2-(#2/#1)*#1}. This works just as well, but a
%D bit more complex.

\def\modulonumber#1#2{\the\numexpr#2-((((#2+(#1/2))/#1)-1)*#1)\relax}

%D \macros{modulatednumber}
%D
%D Modulo numbers run from zero to one less than the limit, but for conversion sets,
%D we need a value between 1 and the limit. The \type {\modulatednumber} arranges
%D that. This macro also needs to be fully expandable, resulting in two \type
%D {\numexpr}s.

\def\modulatednumber#1#2%
  {\ifnum\the\numexpr\modulonumber{#1}{#2}\relax=0 #1%
   \else \the\numexpr\modulonumber{#1}{#2}\relax  \fi}

%D \macros{setcalculatedsin,setcalculatedcos,setcalculatedtan}

\unexpanded\def\setcalculatedsin#1#2{\edef#1{\clf_sind#2}}
\unexpanded\def\setcalculatedcos#1#2{\edef#1{\clf_cosd#2}}
\unexpanded\def\setcalculatedtan#1#2{\edef#1{\clf_tand#2}}

%D \macros{formatted,format}

           \def\formatted#1{\ctxcommand{format(#1)}} % not clf
\unexpanded\def\format   #1{\ctxcommand{format(#1)}} % not clf

%D The \type {\modulatednumber} and \type {\realnumber} macros have been removed.

\protect \endinput