This doesn’t seem sufficient as soon as you want to perform some kind of structural substitution, for example doing the equivalent of s/"([^"]*)"/'$1'/. If it could do that and also somehow be able to replace any of the [^"] that match ['] by \', that would seem more useful.
More generally speaking, since regular expressions effectively define a parse tree on their matches, being able to perform more general transformations of those trees would be useful.
More generally speaking, since regular expressions effectively define a parse tree on their matches, being able to perform more general transformations of those trees would be useful.