Undefined value of parameter NamedCaptureGroups is Annex B for ClassAtomNoDash

[lgalfaso]

Description: Value of the parameter NamedCaptureGroups should be defined for the extended version of ClassAtomNoDash

B.1.2 Regular Expressions Patterns extends the regular expressions grammar. It extends the original ClassAtomNoDash

ClassAtomNoDash[UnicodeMode] ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape[?UnicodeMode]

with ClassAtomNoDash

ClassAtomNoDash[UnicodeMode, NamedCaptureGroups] ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape[?UnicodeMode, ?NamedCaptureGroups]
    \ [lookahead = c]

The extended version has one more parameter (NamedCaptureGroups). All other symbols that make use of ClassAtomNoDash do not define the parameter NamedCaptureGroups for ClassAtomNoDash (all uses of ClassAtomNoDash as a non-terminating symbol are outside Annex B).

If one were to follow the definitions of how the grammar parameters should be understood, then the extended definition of ClassAtomNoDash is

ClassAtomNoDash ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape
    \ [lookahead = c]

ClassAtomNoDash_UnicodeMode ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape_UnicodeMode
    \ [lookahead = c]

ClassAtomNoDash_NamedCaptureGroups ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape_NamedCaptureGroups
    \ [lookahead = c]

ClassAtomNoDash_UnicodeMode_NamedCaptureGroups ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape_UnicodeMode_NamedCaptureGroups
    \ [lookahead = c]

given that there are no references in the grammar to ClassAtomNoDash_NamedCaptureGroups nor to ClassAtomNoDash_UnicodeMode_NamedCaptureGroups, then the strictest interpretation of the grammar would be equivalent to the extended version of ClassAtomNoDash being defined as

ClassAtomNoDash[UnicodeMode] ::
    SourceCharacter but not one of \ or ] or -
    \ ClassEscape[?UnicodeMode, ~NamedCaptureGroups]
    \ [lookahead = c]

Is this the correct interpretation of the extended grammar?

[jmdyck]

Yup, this is a known spec bug. See #1081 (comment) and #2037 (comment) (both from before N changed to NamedCaptureGroups).