Set EastAsianWidth::UNICODE_VERSION

[elfham]

fix #438

The beginning of the comment in EastAsianWidth.txt contains the Unicode version.

% head -3 EastAsianWidth.txt
# EastAsianWidth-15.0.0.txt
# Date: 2022-05-24, 17:40:20 GMT [KW, LI]
# © 2022 Unicode®, Inc.
% 

At least since Unicode 3.2.0, the version seems to be included.

% curl --silent https://www.unicode.org/Public/3.2-Update/EastAsianWidth-3.2.0.txt | head -3
# EastAsianWidth-3.2.0.txt
#
# East Asian Width Properties
%

So, the version is retrieved from there.

% ruby bin/generate_east_asian_width EastAsianWidth.txt | head
class Reline::Unicode::EastAsianWidth
  # This is based on EastAsianWidth.txt
  # EastAsianWidth.txt
  UNICODE_VERSION = '15.0.0'

  # Fullwidth
  TYPE_F = /^[#{ %W(
    \u{3000}
    \u{FF01}-\u{FF60}
    \u{FFE0}-\u{FFE6}
%

The version is set to Reline::Unicode::EastAsianWidth::UNICODE_VERSION.

The variable name UNICODE_VERSION is taken from RbConfig::CONFIG["UNICODE_VERSION"].

If the comment format is changed in the future and the Unicode version fails to be retrieved, a warning will be displayed and set UNICODE_VERSION = nil.

% ruby bin/generate_east_asian_width <(tail +2 EastAsianWidth.txt) > /dev/null
Failed to get UNICODE_VERSION
% ruby bin/generate_east_asian_width <(tail +2 EastAsianWidth.txt) | grep UNICODE_VERSION
Failed to get UNICODE_VERSION
  UNICODE_VERSION = nil
% 

[ima1zumi]

Since this constant is not used in Reline, why not leave it as a comment?

[elfham]

OK, I fixed the code that way.

[ima1zumi]

👍