Re: [NTG-context] right and left arrowfill

[Carlos via ntg-context <ntg-context@ntg.nl>]

On Thu, Jun 22, 2023 at 03:32:25PM +0200, Hans van der Meer via ntg-context wrote:
> \starttext
>    x \rightarrowfill x
> 
>    x \leftarrowfill x
> 
> hbox to 5cm:
> 
>    y\hbox to5cm{\rightarrowfill}y
> 
>    y\hbox to5cm{\leftarrowfill}y
> \stoptext
> 
> But obviously not in an dimensioned \hbox, whereas Knuth's version does that too.
> 
> 
> 
> > On 22 Jun 2023, at 15:11, Hans Hagen via ntg-context <ntg-context@ntg.nl> wrote:
> > 
> >    x \rightarrowfill x
> > 
> >    x \leftarrowfill x
> 
> yours sincerely
> dr. Hans van der Meer
> 
> 

I find this interesting. I agree with Hans vdM.

So what would be the acceptable standard given an x length of a glue? 

In the above examples, it's all preset.

Is a rule of thumb — no pun intended here — to apply thereafter
a glue, in this case a \vrule that follows the box and precedes the
other glue? that is, the \rightarrowfill or \leftarrowfill?

I mean. Once you get the glues messed up, the whole box crumbles. 

How good would \meaning be here, notwithstanding the valuable info of
the macro it provides, if it can't print out, let alone source it up,
the more accurate dimension, let alone the measurement.

So, one would need to know the preset layout of the page to have an idea
about it? 

Hans H. pulled the old modified trick of 'works here'. 

Like a magician… now all of a sudden evetything works, but unlike TeX's

\hbox to 1in{\vrule \rightarrowfill \ 1in \leftarrowfill\vrule} 

or

\hbox to 1cm{\vrule \rightarrowfill \ 1cm \leftarrowfill\vrule} 

which gives an accurate description, not to mention measurement, 

a 

\vbox to 5pt{x\vrule\rightarrowfill \ x \leftarrowfill\vrule\ x}

or 

x \rightarrowfill x
x \leftarrowfill x 

or

\vbox to 3pt{x\vrule\rightarrowfill \  \leftarrowfill\vrule\ x}

\ \rightarrowfill \ 
\ \leftarrowfill \ 


in LMTX doesn't say much 

-- 
C for yourself.

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