Regex: Named groups/backreferences
Lars T Hansen
lth at acm.org
Thu Sep 13 09:12:10 PDT 2007
On 9/13/07, liorean <liorean at gmail.com> wrote:
> Got some questions about named groups:
> "Group names must be valid lexical identifiers, and each group name
> must be defined only once within a regular expression."
> 1. Is this meant to indicate that regex add their own lexical scopes;
> partake in the lexical scope of their containing function if any;
> the identifier must be unique within the regex
> and that that null,
> true, false, this etc. that are reserved keywords cannot be used (i.e.
> the Identifier construct); or just that they need to conform to the
> identifier syntax but reserved keywords are allowed (i.e. the
> IdentifierName construct)?
The latter, but thanks for asking; I should clarify that in the spec.
> 2. Can (?P=varname) refer to a lexical variable varname from a
> containing scope,
> or just to groups within the regex itself?
> 3. If it can refer to a variable in a containing scope, what
> constraints are put on the variable type, what conversions are made,
> David "liorean" Andersson
> Es4-discuss mailing list
> Es4-discuss at mozilla.org
More information about the Es4-discuss