1%D \module 2%D [ file=syst-lua, 3%D version=2008.01.25, 4%D title=\CONTEXT\ System Macros, 5%D subtitle=Helper macros based on \LUA, 6%D author=Hans Hagen, 7%D date=\currentdate, 8%D copyright={PRAGMA ADE \& \CONTEXT\ Development Team}] 9%C 10%C This module is part of the \CONTEXT\ macro||package and is 11%C therefore copyrighted by \PRAGMA. See mreadme.pdf for 12%C details. 13 14\registerctxluafile{syst-lua}{} 15 16\unprotect 17 18\def\expdoifelse#1#2{{#1}{#2}} 19\def\expdoif #1#2{ {#1}{#2}} 20\def\expdoifnot #1#2{ {#1}{#2}} 21 22%D Here is variant using a brainwave of the 12\high{+} hour \quotation {Long Road 23%D Out of Eden}\footnote {Eden being Backo\TeX\ 2018, where the virtues of the \type 24%D {\expanded} primitive were mentioned in talks.} trip. For now I don't really see 25%D other useful applications. 26 27\def\expandeddoifelse#1#2% 28 {\immediateassignment\edef\m_syst_string_one{#1}% 29 \immediateassignment\edef\m_syst_string_two{#2}% 30 \ifx\m_syst_string_one\m_syst_string_two 31 \expandafter\firstoftwoarguments 32 \else 33 \expandafter\secondoftwoarguments 34 \fi} 35 36\def\expandeddoif#1#2% 37 {\immediateassignment\edef\m_syst_string_one{#1}% 38 \immediateassignment\edef\m_syst_string_two{#2}% 39 \ifx\m_syst_string_one\m_syst_string_two 40 \expandafter\firstofoneargument 41 \else 42 \expandafter\gobbleoneargument 43 \fi} 44 45\def\expandeddoifnot#1#2% 46 {\immediateassignment\edef\m_syst_string_one{#1}% 47 \immediateassignment\edef\m_syst_string_two{#2}% 48 \ifx\m_syst_string_one\m_syst_string_two 49 \expandafter\gobbleoneargument 50 \else 51 \expandafter\firstofoneargument 52 \fi} 53 54% \testfeatureonce{100000}{\doifelse{hello world}{here i am}{}} % 0.3 55% \testfeatureonce{100000}{\expandabledoifelse{hello world}{here i am}{}} % 1.5 56 57\def\expdoifelsecommon#1#2{{#1}{#2}} 58\def\expdoifelseinset #1#2{ {#1}{#2}} 59 60\let\expdoifcommonelse\expdoifelsecommon 61\let\expdoifinsetelse \expdoifelseinset 62 63%D We define these here, just in case. This permits \typefile {self} otherwise 64%D nested b|/|e sep problems. 65 66\def\luastringsep{===} 67 68\edef\!!bs{[\luastringsep[} 69\edef\!!es{]\luastringsep]} 70 71\protected\def\writestatus#1#2{{#1}{#2}} 72 73%D We can omit the tex.ctxcatcodes here as nowadays we seldom change the regime at 74%D the \TEX\ end: 75 76%def\luaexpr#1{\ctxlua{context (tostring(#1))}} % more efficient: 77\def\luaexpr#1{tex.print(tostring(#1))} % no use in shortcutting has to be compiled 78 79%D But as we only use write 16 we could as well do all in \LUA\ and ignore the rest. 80%D Okay, we still can do writes here but only when not blocked. 81 82\let\syst_write_execute % always {...} 83 84%D There is a probably rather useless \type {\expression} command that can mix \LUA\ numeric 85%D expressions with \TEX\ commands (for as far that makes sense) that works like this: 86%D 87%D \starttyping 88%D \mathchardef\foooo 1234 89%D \def \mymacro {123.45} 90%D \scratchdimen 123pt 91%D \scratchskip 123pt 92%D \scratchtoks {34} 93%D 94%D \testfeatureonce{10000}{\edef\foo{\expression 95%D round( 96%D 12.3 * \scratchdimen 97%D - (12.3 * \scratchskip) / 2 98%D + 2 ^ 3 99%D * ( 100%D - sqrt(12) 101%D - 10pt 102%D - \foooo 103%D + \luatexversion 104%D - \mymacro 105%D + \scratchtoks 106%D + \the\scratchcounter 107%D + \number\scratchcounter 108%D ) 109%D ) 110%D \relax}} 111%D 112%D \expression string.format("\letterpercent f",\elapsedtime/50000) \relax 113%D \stoptyping 114%D 115%D The final \type {\relax} is mandate because we also accept spaces. Of course we 116%D could have avoided it by using outer parenthesis but this is cleaner anyway. 117%D 118%D The \MKIV\ version is a bit more limited than the \LMTX\ version because it only 119%D supports the standard math functions. 120 121% maybe: \let\texexpr\expression 122 123\protect \endinput 124 |
