On Thu, 29 Jun 2006, Hans Hagen wrote:
Aditya Mahajan wrote:
I am simply trying to copy from amsmath definition.
better think context -)
\unprotect
\def\mtharrfactor{1} \def\mtharrextra {0}
\def\domthxarr#1#2#3#4#5#6#7#8% {\begingroup \def\mtharrfactor{1}% \def\mtharrextra {0}% \processaction[#1] % will be sped up [ \v!none=>\def\mtharrfactor{0}, \v!small=>\def\mtharrextra{10}, \v!medium=>\def\mtharrextra{15}, \v!big=>\def\mtharrextra{20}, \v!normal=>, \v!default=>, \v!unknown=>\doifnumberelse{#1}{\def\mtharrextra{#1}}\donothing]% \mathsurround\zeropoint \muskip0=#4mu \muskip0=\mtharrfactor\muskip0 \advance\muskip0 \mtharrextra mu \muskip2=#5mu \muskip2=\mtharrfactor\muskip2 \advance\muskip2 \mtharrextra mu \setbox0\hbox{$\scriptstyle \if#20\else\mkern#2mu\fi \mkern\muskip0\relax #8\relax \mkern\muskip2\relax \if#30\else\mkern#3mu\fi $}% \setbox4\hbox{#6}% \dimen0\wd0 \ifdim\wd4>\dimen0 \dimen0\wd4 \fi \setbox2\hbox{$\scriptstyle \if#20\else\mkern#2mu\fi \mkern\muskip0\relax #7\relax \mkern\muskip2\relax \if#30\else\mkern#3mu\fi $}% \ifdim\wd2>\dimen0 \dimen0\wd2 \fi \setbox4\hbox to \dimen0{#6}% \mathrel{\mathop{% \hbox to \dimen0{\hss\copy4\hss}}% \limits^{\box0}_{\box2}} \endgroup}
% ams:
\def\xrightarrow{\doifnextcharelse[\noxrightarrow\doxrightarrow} \def\xleftarrow {\doifnextcharelse[\noxleftarrow\doxleftarrow}
\def\doxrightarrow{\dodoublegroupempty\dodoxrightarrow} \def\doxleftarrow {\dodoublegroupempty\dodoxleftarrow }
\def\noxrightarrow[#1]{\dodoublegroupempty\dodoxrightarrow{#1}} \def\noxleftarrow [#1]{\dodoublegroupempty\dodoxleftarrow {#1}}
\def\dodoxrightarrow#2#3{\mathrel{{\domthxarr{}0359\rightarrowfill{#1}{#2}}}} \def\dodoxleftarrow #2#3{\mathrel{{\domthxarr{}3095\leftarrowfill {#1}{#2}}}}
% context:
\def\xrightarrow {\dosingleempty\doxrightarrow} \def\xleftarrow {\dosingleempty\doxleftarrow}
\def\doxrightarrow[#1]{\dotriplegroupempty\dodoxrightarrow{#1}} \def\doxleftarrow [#1]{\dotriplegroupempty\dodoxleftarrow {#1}}
\def\dodoxrightarrow#1#2#3{\mathrel{{\domthxarr{#1}0359\rightarrowfill{#2}{#3}}}} \def\dodoxleftarrow #1#2#3{\mathrel{{\domthxarr{#1}3095\leftarrowfill {#2}{#3}}}}
\starttext
\startformula \xrightarrow{}{stuff on top}\stopformula \startformula \xrightarrow{stuff below}{}\stopformula \startformula \xrightarrow{stuff below}{stuff on top}\stopformula
\startformula \xleftarrow [none]{stuff below}{stuff on top}\stopformula \startformula \xleftarrow [small]{stuff below}{stuff on top}\stopformula \startformula \xleftarrow [medium]{stuff below}{stuff on top}\stopformula \startformula \xleftarrow [big]{stuff below}{stuff on top}\stopformula
\stoptext
This definitely looks better. Can there be a setting for \setuparrowextension (or something) so that the default can be changed. On Thu, 29 Jun 2006, Taco Hoekwater wrote:
Perhaps it syntax should be identical to amsmath: no brackets and two required arguments.
But that is not the amsmath syntax. It has \xrightarrow[below]{top} where the first argument is optional.
It is what is expected anyway.
\def\xrightarrow#1#2{\mathrel {{\domthxarr0359\rightarrowfill{#1}{#2}}}}
I agree that this makes more sense.
I assume amsmath has a few others as well, for double arrows and such. Can you post those defs as well? Then we can move the whole definition into math-ext.tex for the new release
On Thu, 29 Jun 2006, Hans Hagen wrote:
hm, this is not the context way, two equal kind of contents and then one of them in [], maybe
I agree. To me, \xrightarrow[setting]{below}{top} makes most sense. It is not same as ams syntax, but that does not matter too much. Maybe there can be a switch to enable ams type of syntax, but that will make things too messy, I guess.
\def\xrightarrow{\doifnextcharelse[\noxrightarrow\doxrightarrow} \def\xleftarrow {\doifnextcharelse[\noxleftarrow\doxleftarrow}
\def\doxrightarrow{\dodoublegroupempty\dodoxrightarrow} \def\doxleftarrow {\dodoublegroupempty\dodoxleftarrow }
\def\noxrightarrow[#1]{\dodoublegroupempty\dodoxrightarrow{#1}} \def\noxleftarrow [#1]{\dodoublegroupempty\dodoxleftarrow {#1}}
which accepts
\xrightarrow{x}{y} \xrightarrow{x} \xrightarrow{}{y} \xrightarrow[x]{y}
etc, actyally, we should then also accept
\xrightarrow[x][y]
but more interesting is to use the optional arg for tuning purposes
\if0#1\else\mkern#1mu\fi
test, does a \mkern0mu hurt?
I did not see any difference when I tested it. I do not know why that is there. On Thu, 29 Jun 2006, Taco Hoekwater wrote:
I assume amsmath has a few others as well, for double arrows and such. Can you post those defs as well? Then we can move the whole definition into math-ext.tex for the new release
These are the only ones defined in amsmath. However extarrows.sty defines the following \xlongequal (===) \xLongleftarrow (<===) (Perhaps a better name is \xLeftarrow and we can have \xLeftarrow[medium] ) \xLongrightarrow (===>) (Perhaps a better name is \xRightarrow?) \xLongleftrightarrow (<=====>) (again, \xLeftrightarrow[medium] ) \xLeftrightarrow ( <===> ) \xlongleftrightarrow (<------->) (again \xleftrightarrow[medium] ) \xleftrightarrow (<---->) \xlongleftarrow \xlongrightarrow (These two are there with \xrightarrow[medium]) The definitions in extarrows are \def\x@arrow{\DOTSB\Relbar} \def\xlongequalsignfill@{\arrowfill@\x@arrow\Relbar\x@arrow} \newcommand{\xlongequal}[2][]{% \ext@arrow 0099\xlongequalsignfill@{#1}{#2}} \def\xLongleftrightarrowfill@{% \arrowfill@\Longleftarrow\Relbar\Longrightarrow} \newcommand{\xLongleftrightarrow}[2][]{% \ext@arrow 0099\xLongleftrightarrowfill@{#1}{#2}} \def\xlongleftrightarrowfill@{% \arrowfill@\longleftarrow\relbar\longrightarrow} \newcommand{\xlongleftrightarrow}[2][]{% \ext@arrow 0099\xlongleftrightarrowfill@{#1}{#2}} \def\xLeftrightarrowfill@{\arrowfill@\Leftarrow\Relbar\Rightarrow} \newcommand{\xLeftrightarrow}[2][]{% \ext@arrow 0099\xLeftrightarrowfill@{#1}{#2}} \def\xleftrightarrowfill@{\arrowfill@\leftarrow\relbar\rightarrow} \newcommand{\xleftrightarrow}[2][]{% \ext@arrow 0099\xleftrightarrowfill@{#1}{#2}} \def\xLongleftarrowfill@{\arrowfill@\Longleftarrow\Relbar\Relbar} \newcommand{\xLongleftarrow}[2][]{% \ext@arrow 0099\xLongleftarrowfill@{#1}{#2}} \def\xLongrightarrowfill@{\arrowfill@\Relbar\Relbar\Longrightarrow} \newcommand{\xLongrightarrow}[2][]{% \ext@arrow 0099\xLongrightarrowfill@{#1}{#2}} \def\xlongleftarrowfill@{\arrowfill@\longleftarrow\relbar\relbar} \newcommand{\xlongleftarrow}[2][]{% \ext@arrow 0099\xlongleftarrowfill@{#1}{#2}} \def\xlongrightarrowfill@{\arrowfill@\relbar\relbar\longrightarrow} \newcommand{\xlongrightarrow}[2][]{% \ext@arrow 0099\xlongrightarrowfill@{#1}{#2}} I do not think that change is syntax is that big a deal, as long as it is documented (I will do that). Otherwise we will still be using latex syntax here :) Aditya