Issue #10891 has been updated by Shugo Maeda. Assignee changed from ruby-core to Yui NARUSE How about to interpret `[[:punct]]` as `[\p{P}\p{S}]` for unicode strings so that `[[:punct]]` will be a superset of POSIX's one? ---------------------------------------- Bug #10891: /[[:punct:]]/ POSIX group broken (with string literals?) https://bugs.ruby-lang.org/issues/10891#change-55146 * Author: Tom Lord * Status: Open * Priority: Normal * Assignee: Yui NARUSE * ruby -v: ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-linux] * Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN ---------------------------------------- The regular expression: `/[[:punct:]]/` should match the following characters: ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~ However, it only works for these characters: ! " # % & ' ( ) * , - . / : ; ? @ [ \\ ] _ { } And does not work for these characters: $ + < = > ^ ` | ~ However, this is where it gets really weird... Consider the following: 60.chr == "<" # true 60.chr =~ /[[:punct:]]/ # => 0 "<" =~ /[[:punct:]]/ # => nil So, it seems that the regular expression only fails for string literals! -- https://bugs.ruby-lang.org/