RFC 9485, "I-Regexp: An Interoperable Regular Expression Format", October 2023

Errata ID: 7990
Status: Reported
Type: Technical
Publication Format(s) : TEXT, PDF, HTML
Reported By: Bjoern Hoehrmann
Date Reported: 2024-06-13

Section 5.1 says:

5.1.  Multi-Character Escapes

   I-Regexp does not support common multi-character escapes (MCEs) and
   character classes built around them.  These can usually be replaced
   as shown by the examples in Table 1.

                      +============+===============+
                      | MCE/class: | Replace with: |
                      +============+===============+
                      | \S         | [^ \t\n\r]    |
                      +------------+---------------+
                      | [\S ]      | [^\t\n\r]     |
                      +------------+---------------+
                      | \d         | [0-9]         |
                      +------------+---------------+

It should say:

5.1.  Multi-Character Escapes

   I-Regexp does not support common multi-character escapes (MCEs) and
   character classes built around them.  These can usually be replaced
   as shown by the examples in Table 1.

                      +============+===============+
                      | MCE/class: | Replace with: |
                      +============+===============+
                      | \d         | [0-9]         |
                      +------------+---------------+

Notes:

`\S` excludes the form feed and vertical tabulation characters in Perl, ECMAScript, and other implementations, while the suggested replacement includes them. Given the entire document is about interoperable regular expressions, misrepresentation of the common definition of `\S` runs counter to that. Including form feed and vertical tabulation literally in the replacement expression is not likely to be helpful, so removing the misleading rows seems to be the best option.

Report New Errata