On Wed, Dec 14, 2022 at 7:30 PM Tom Honermann <tom_at_[hidden]> wrote:

> On 11/30/22 5:26 PM, Corentin via SG16 wrote:
>
> Hello folks.
> Here is a list of all the codepoint that change
>
> https://gist.githubusercontent.com/cor3ntin/b7f4f52893b0b54890e970f7bbec6118/raw/720a910585d78c9ceb4e0458dcef87af2a436121/width.md
>
> Just a note: the gist has 8570 characters and that count matches the
> ranges specified in the D2675R1
> <https://isocpp.org/files/papers/D2675R1.pdf> annex.
>
>
> Simply cat that file in the terminal.
> The screenshot below is a render on ITerm2
> You will notice the tofu for reserved codepoints is considered narrow
> but doesn't quite fit so it overlaps with the next cell, same for the
> number in square.
>
>
> [image: Screenshot 2022-11-30 at 23.19.47.png]
>
> As discussed previously, a single screen shot that only shows a small
> subset of the relevant characters is not sufficient to demonstrate that the
> conclusions of the paper are consistent with existing behavior. I continue
> to have reservations about the screen shots in the paper for this reason; I
> don't see how they provide useful information at all. I think they are
> actively misleading since they do not appear to show behavior that is
> consistent with the intent of the paper.
>
> I spent some time analyzing the behavior of all 8570 characters in the
> terminal I use (Konsole 12.12.3 with the Hack 10pt font). Here is what I
> found:
>
> - For the characters that the paper changes from width 1 to width 2
> (based on the listings in the annex), the following are displayed with a
> width other than 2:
> - Width 0:
> - U+016FE4 (KHITAN SMALL SCRIPT FILLER)
> - Width 1: (These were all displayed as tofu; some are probably
> unassigned characters, others are probably unknown by the font)
> - U+01AFF0 .. U+01AFFE
> - U+01B11F .. U+01B132
> - U+01B155
> - U+01F6DC .. U+01F6DF
> - U+01F7F0
> - U+01FA75 .. U+01FA77
> - U+01FA7B .. U+01FA7C
> - U+01FA87 .. U+01FA88
> - U+01FAA9 .. U+01FAAF
> - U+01FAB7 .. U+01FABF
> - U+01FAC3 .. U+01FACF
> - U+01FAD7 .. U+01FAF8
>
>
All of these are listed in the paper, and are all assigned. Mostly
hiragana, katana and emojis.
the only unassigned code points of with 2 are in the
ranges 4E00..9FFF, 20000..2FFFF, 20000..2FFFF


>
> -
> - For the characters that the paper changes from width 1 to width 2
> (based on the listings in the annex), the following are displayed with a
> width other than 1:
> - Width 2:
> - U+003248 .. U+00324F (CIRCLED NUMBER TEN ON BLACK SQUARE ..
> CIRCLED NUMBER EIGHTY ON BLACK SQUARE)
>
> These results strongly match the intent of the paper and that the open
> question regarding the last group of characters should be answered such
> that they do not change width.
>
> This is the kind of analysis I would like to see performed for other
> terminals so that we can qualitatively compare behavior between them. I
> attached C++ source code I used to display the characters.
>
> Tom.
>
>
>
> FYI Iterm2 also uses Unicode UAX 44
>
> https://github.com/gnachman/iTerm2/blob/master/sources/NSCharacterSet+iTerm.m#L464
>
>