Bug #11859: Regexp matching with \p{Upper} and \p{Lower} for EUC-JP doesn’t work.

• Status: Rejected
• Assignee: -
• Target version: -
• ruby -v: ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-darwin14]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

[matsui (Kimihito Matsui)]

U+FF21 (Ａ, FULLWIDTH LATIN CAPITAL LETTER A) and U+00c0 (À, LATIN CAPITAL LETTER A WITH GRAVE) is Uppercase_Letter so it should match and return 0 in following case but this returns 1.

ruby -e 'puts "\uFF21A".encode("EUC-JP") =~ Regexp.compile("\\\p{Upper}".encode("EUC-JP”))' # => 1
ruby -e 'puts "\u00C0A".encode("EUC-JP") =~ Regexp.compile("\\\p{Upper}".encode("EUC-JP"))’ # => 1

This also happens in lower case matching.

ruby -e 'puts "\uFF41a".encode("EUC-JP") =~ Regexp.compile("\\\p{Lower}".encode("EUC-JP"))’ ＃=> 1

In Unicode encoding it works as follows.

ruby -e 'puts "\uFF21A" =~ Regexp.compile("\\\p{Upper}")'  # => 0

Looks like EUC-JP \p{Upper} and \p{Lower} regex is limited to ASCII characters.

[matsui (Kimihito Matsui)]

• Description updated (diff)

[matsui (Kimihito Matsui)]

• Description updated (diff)

[naruse (Yui NARUSE)]

• Status changed from Open to Rejected

Ruby doesn't have case tables for non Unicode encodings.

And EUC-JP is legacy encoding, I don't think such encoding should be extended.

[duerst (Martin Dürst)]

Some additional comments following up on the commiters' meeting yesterday:

There are many single-byte non-Unicode encodings that have case tables.

Checking the paper versions of the standards in question, À (LATIN CAPITAL LETTER A WITH GRAVE) exists in JIS X 0212-1990 at position (区点) 10-2, and in JIS X 0213-2004 at position 9-23 on the first plane (面). JIS X 0213-2004 is the version I have at hand, but that character didn't change from the -2000 version.

Checking the actual encoding of À in EUC-JP in Ruby shows the following:

$ ruby -e 'puts "\u00C0".encode("EUC-JP").b.inspect'
"\x8F\xAA\xA2"

This is clearly the JIS X 0212-1990 version, using SS3 (0x8F) to switch to the JIS X 0212 plane at G3. The 1990 version of JIS X 0212 is the first one, so the À character didn't exist in EUC-JP before.

[duerst (Martin Dürst)]

• Related to Feature #13770: Can't create valid Cyrillic-named class/module added