Re: [NTG-context] autospacing and colonequals (was Lucida-1.901 (2023-01-21) available)

26 Jan 2023

      Hi Hans and Mikael,

Thank you both for your attention to my reply and the clarification and hints regarding the comman \colonequals and 
	\setupmathematics[autospacing=yes]

Indeed the command \colonequals give the precise expected alignment for the combination glyph « := ». Befors changing the combination « := » to \columnequals in my documents, I am wondering whether one could add a small lua code in order to make an automatic replacement at run time. Actually, since I don’t know of any other instance in which the combination « := » is used to mean something else, would it not be reasonnable to make « := » synonym to \colonequals?

I played a little bit with 
	\setupmathematics[autospacing=yes]
and it seems to me that without this command one gets automatic spacing in math mode, while with the above command the spacing obeys what has been inserted in the source. Is this behaviour intended, or is there a mismatch between 
	\setupmathematics[autospacing=yes]
and
	\setupmathematics[autospacing=no]

Best regards: Otared
...
On 26 Jan 2023, at 10:33, Hans Hagen via ntg-context mailto:ntg-context@ntg.nl> wrote:
On 1/25/2023 6:24 PM, Mikael Sundqvist via ntg-context wrote:
...
On Wed, Jan 25, 2023 at 11:02 AM Otared Kavian via ntg-context
mailto:ntg-context@ntg.nl> wrote:
...
Hi,
Thanks Hraban for the information and the link to the article by Hans and Mikael about the math fonts in Lucida.
I very much appreciated that article: one sees how the handling of almost impercebtile details in ConTeXt make us to adhere to and love LuaMetaTeX… So a great thank you to Hans and Mikael for all this work!
Regarding the details of vertical alignment in math, I wonder whether the column « : » in front of the equal sign « = », in the combination « := » (used to define for instance a new variable) should be alos centered around the math axis, as explained in the article. For instance in the following example
\setupbodyfont[lucidaot,12pt]
\starttext
\startformula
f(x) := -(u|x) := - \langle u, x \rangle
\stopformula
\stopformula
\startformula
f : A \longrightarrow B
\stopformula
\stoptext
it seems to me that the lower dot (or square…) in the semicolumn of the first formula (in front of the equal sign) is lower than in the second formula.
Best regards: Otared
Thank you for the kind words, Otared,
Regarding the colons (and other symbols with "dots"), I would say it
is still not optimal in Lucida (and difficult to make it "consistent",
there are too many symbols that are at the moment different). But in
your example you can use \colonequals and \colon if you prefer. They
are centered around the math axis.
Best, Mikael
\setupbodyfont[lucidaot,12pt]
\starttext
\startformula
f(x) := -(u|x) \colonequals - \langle u, x \rangle
\stopformula
\startformula
f : A \longrightarrow B \breakhere
f \colon A \longrightarrow B
\stopformula
\startformula
\mathaxisbelow := \colonequals : \colon
\stopformula
\stoptext
There is a (experimental as we played with it and then got distracted) feature that makes some symbols adapt to spacing in the input.
\starttext
\setupmathematics[autospacing=yes]
\setupmathematics[collapsing=2]
\im{A:B} and \im{A : B}\par
   \im{A:=B} and \im{A := B}\par
   \im{A\colonequals B} and \im{A {\colonequals} B}\par
\stoptext
the second line is not yet ok as collapsing the := (old feature) comes at the wrong time when we do autospacing (something Mikasl and I now need to discuss and test)
This autospacing is part of some larger effort, for instance we can also auto handle fences and so. All this relates to minimizing the input and make it a bit more natural. Think (1,2) vb (1, 2) where we - due to the many more classes that we have - want spacing to be right.
All will be revealed in the upcoming releases and the upcoming 3145 page math manual.
Hans
-----------------------------------------------------------------
                                         Hans Hagen | PRAGMA ADE
             Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
      tel: 038 477 53 69 | www.pragma-ade.nl http://www.pragma-ade.nl/ | www.pragma-pod.nl http://www.pragma-pod.nl/
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the Wiki!
maillist : ntg-context@ntg.nl mailto:ntg-context@ntg.nl / https://www.ntg.nl/mailman/listinfo/ntg-context https://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : https://www.pragma-ade.nl https://www.pragma-ade.nl/ / http://context.aanhet.net http://context.aanhet.net/
archive  : https://bitbucket.org/phg/context-mirror/commits/ https://bitbucket.org/phg/context-mirror/commits/
wiki     : https://contextgarden.net https://contextgarden.net/
___________________________________________________________________________________
Otared Kavian
e-mail: otared@gmail.com mailto:otared@gmail.com
Phone: +33 6 88 26 70 95