Ecma-48 proposed styling controls update updated & math expression representation proposal update

[Giacomo Catenazzi]

On 9 Jan 2024 23:12, Kent Karlsson wrote:
(...)

Let's skip a lot of *details*.

>>
>> But how do you input the formatting?
> 
> For output to a terminal emulator from a program, the source program would have string constants for control sequences or parts thereof, just like done now.
> 
> For a styling enhanced plain text editor one should be able to select a text portion, and then use a menu or keyboard shortcut to select a styling, as it is done in just about any modern text editor. There is no need for an end user to see the styling codes. Using something like HTML syntax would have terrible consequences in that it is hard to tell content from controls. For HTML for instance one MUST use < for <, so that it is not taken as start of a “tag”. That is absolutely nothing you want to see for a terminal, nor for a styling enhanced plain text editor.

I dislike this part, and I think it is the main problem.

Note: I'm actively fighting the use of "string constants" for CSI, in 
programs. Note: maybe we have a different interpretation.

For emulators I want that they uses libraries or at least they check 
terminal capabilities and they issues formatting codes (CSI, from 
ECMA-48 or common usage which are de-facto standards).

Every terminal emulator is different, and users want to use it also 
differently (so changing the settings). A programmer should not make a 
choice for me.

Do a program want to print on console? I'm ok that it may write some 
warnings in colours (but often they fails: they assume a background 
colour (and please: it is my choice!)), if I want to write to a log 
file, no CSI codes.

Hard coded formatting code are bad (and BTW html strongly discourage 
them, for reason: we learn from past).

And now I stop with the first rant.


HTML (and LaTeX) can format text according the medium, and HTML is 
responsive. I find no good way to do it with ECMA-48 style. We can ask 
the size of the screen, or get a signal when it changes, but there is 
not real support on emulators: rendering is performed by programs (e.g. 
using dialog, or directly with curses library). Could you find a good 
way to display in a sensible way tables with different terminal widths 
(starting from 40 or less columns?). It is not code we want in most (or 
any) terminal emulator.

But also in an editor...I feel that programmers must transform it in 
html/css, do the rendering with existing libraries (which they are 
huge), and render it as text + CSI.


What problem are you solving? Real case problem. The more I look the 
proposal, the more I think other tools are much easier and simpler.

Note: HTML with years solved many problems (also considering colour 
blind people, printing, etc.). Note: HTML as technology, not what we got 
from web (but so, possibly you should implement your proposal in that 
way: you just convert CSI to html (DOM), and lets' display it): so we 
have a real case to look. (and there are already libraries that do it, 
but without your extension proposal).

Your proposal is in any case doesn't maintain plain text: CSI sequences 
have punctuation, letters and numbers. So there is no much differences 
of text in elements and tags in HTML: a program/person which want the 
plain text, e.g. for copy/past, must do a lot of work removing 
formatting. In modern html is easy.


I find it would have been  nice idea if we were in 1990s (and so an 
alternative of HTML), but now we have good designs, so do not let's to 
duplicate the huge work HTML did in past). For a practical point (if I 
need to implement it): just a filter to a DOM engine (which at the end 
would be a subset of existing HTML engines) and a rendering (which trend 
go in direction of HTML like formatting API for different graphical 
environment).


And in any case, you should start at a higher layer: show programs, and 
if it is useful emulators and editors will adopt it. Or like tmux (so a 
sort of filter, and IIRC in past some *extensions*, e.g. the UTF-8 where 
done first as filter between user and terminal emulator.

	cate