Re: Nath, and problems smashing

[Simon Pepping <spepping@scaprea.hobby.nl>]

Hi,
On Fri, Apr 11, 2003 at 10:42:28PM +0200, Giuseppe Bilotta wrote:
> Hello,
> 
> as I might have mentioned before, I'm working on a ConTeXt module
> that would give part of the functionality available in the LaTeX
> package Nath; as I'm not really an expert in either of the topics
> involved, I'm going at it slowly, starting with the simple things;
> the first thing I implemented was a natural way to write
> extensible arrows. It came up pretty fine and works quite good,
> but there seems to be a sizing problem.

A good idea.
 
> As you may notice if you compile the nathtest document, sub and
> superscripts to the single-line arrows are much to high or low;
> browsing about I noticed that in AMS-LaTeX the minus that extends
> the single-line arrows is "smashed", to prevent this problem; I
> did try to smash it (replacing \mathop- with \mathop{\smash-}),
> but it didn't seem to help.

You require two smashes to get the height and depth equal to that of
rightarrow.

\usemodule[nath]

\starttext

Arrowfiller: 
\setbox0\hbox to 6pt{\arrowfiller \hfill }
height: \the\ht0,
depth: \the\dp0.

Smash in arrowfiller: 
\def\arrowfiller {\cleaders \hbox {\mathematics {\mkern -3mu\mathord
{\smash -}\mkern -3mu}}}
\setbox0\hbox to 6pt{\arrowfiller \hfill }
height: \the\ht0,
depth: \the\dp0.

Another smash in the opening minus:
\setbox0\hbox {$\mathop {\mathopen {\smash -}\mkern -6mu \doarrowfill
{\ifsuper \the \supertoks \fi }{\ifsuber \the \subertoks \fi } \mkern
-6mu\mathclose {\rightarrow }}$}
height: \the\ht0,
depth: \the\dp0.

Rightarrow:
\setbox0\hbox {$\rightarrow$}
height: \the\ht0,
depth: \the\dp0.

\stoptext

Regards, Simon

-- 
Simon Pepping
email: spepping@scaprea.hobby.nl