I think "better string processing" is below the level of writing a grammar, even a mini-grammar.
If you treat strings as lists of characters and have good pattern-matching, this problem mostly solves itself, without something as ugly as regular expressions. You have the rich set of list operations, function-based predicates and, with clause selection by pattern, that's mostly what you need.
Yes, I know strings-as-lists seems like a terribly unoptimal thing to do; but it's an optimization challenge (how to optimize a particular backing representation of lists so that certain kinds of operations--subset matching, tokenizing, etc.--happen efficiently?), not something to bake into the language.
