Em Wed, 12 May 2021 18:07:04 +0100
David Woodhouse [off-list ref] escreveu:

On Wed, 2021-05-12 at 14:50 +0200, Mauro Carvalho Chehab wrote:

quoted

Such conversion tools - plus some text editor like LibreOffice  or similar  - have
a set of rules that turns some typed ASCII characters into UTF-8 alternatives,
for instance converting commas into curly commas and adding non-breakable
spaces. All of those are meant to produce better results when the text is
displayed in HTML or PDF formats.  

And don't we render our documentation into HTML or PDF formats? 

Yes.

Are
some of those non-breaking spaces not actually *useful* for their
intended purpose?

No.

The thing is: non-breaking space can cause a lot of problems.

We even had to disable Sphinx usage of non-breaking space for
PDF outputs, as this was causing bad LaTeX/PDF outputs.

See, commit: 3b4c963243b1 ("docs: conf.py: adjust the LaTeX document output")

The afore mentioned patch disables Sphinx default behavior of
using NON-BREAKABLE SPACE on literal blocks and strings, using this
special setting: "parsedliteralwraps=true".

When NON-BREAKABLE SPACE were used on PDF outputs, several parts of 
the media uAPI docs were violating the document margins by far,
causing texts to be truncated.

So, please **don't add NON-BREAKABLE SPACE**, unless you test
(and keep testing it from time to time) if outputs on all
formats are properly supporting it on different Sphinx versions.

-

Also, most of those came from conversion tools, together with other
eccentricities, like the usage of U+FEFF (BOM) character at the
start of some documents. The remaining ones seem to came from 
cut-and-paste.

For instance,  bibliographic references (there are a couple of
those on media) sometimes have NON-BREAKABLE SPACE. I'm pretty
sure that those came from cut-and-pasting the document titles
from their names at the original PDF documents or web pages that
are referenced.

quoted

While it is perfectly fine to use UTF-8 characters in Linux, and specially at
the documentation,  it is better to  stick to the ASCII subset  on such
particular case,  due to a couple of reasons:

1. it makes life easier for tools like grep;  

Barely, as noted, because of things like line feeds.

You can use grep with "-z" to seek for multi-line strings(*), Like:

	$ grep -Pzl 'grace period started,\s*then' $(find Documentation/ -type f)
	Documentation/RCU/Design/Data-Structures/Data-Structures.rst

(*) Unfortunately, while "git grep" also has a "-z" flag, it
    seems that this is (currently?) broken with regards of handling multilines:

	$ git grep -Pzl 'grace period started,\s*then'
	$

quoted

2. they easier to edit with the some commonly used text/source
   code editors.  

That is nonsense. Any but the most broken and/or anachronistic
environments and editors will be just fine.

Not really.

I do use a lot of UTF-8 here, as I type texts in Portuguese, but I rely
on the US-intl keyboard settings, that allow me to type as "'a" for á.
However, there's no shortcut for non-Latin UTF-codes, as far as I know.

So, if would need to type a curly comma on the text editors I normally 
use for development (vim, nano, kate), I would need to cut-and-paste
it from somewhere[1].

[1] If I have a table with UTF-8 codes handy, I could type the UTF-8 
    number manually... However, it seems that this is currently broken 
    at least on Fedora 33 (with Mate Desktop and US intl keyboard with 
    dead keys).

    Here, <CTRL><SHIFT>U is not working. No idea why. I haven't 
    test it for *years*, as I din't see any reason why I would
    need to type UTF-8 characters by numbers until we started
    this thread.
 
In practice, on the very rare cases where I needed to write
non-Latin utf-8 chars (maybe once in a year or so, Like when I
would need to use a Greek letter or some weird symbol), there changes
are high that I wouldn't remember its UTF-8 code.

So, If I need to spend time to seek for an specific symbol, after
finding it, I just cut-and-paste it.

But even in the best case scenario where I know the UTF-8 and
<CTRL><SHIFT>U works, if I wanted to use, for instance, a curly
comma, the keystroke sequence would be:

	<CTRL><SHIFT>U201csome string<CTRL><SHIFT>U201d

That's a lot harder than typing and has a higher chances of
mistakenly add a wrong symbol than just typing:

	"some string"

Knowing that both will produce *exactly* the same output, why
should I bother doing it the hard way?

-

Now, I'm not arguing that you can't use whatever UTF-8 symbol you
want on your docs. I'm just saying that, now that the conversion 
is over and a lot of documents ended getting some UTF-8 characters
by accident, it is time for a cleanup.

Thanks,
Mauro