[Drup]

There is a really easy solution to this: write regexes with combinators.

  star (range 'a' 'z')

Naturally, it's trivial to have a `posix` combinator (or any other syntax, really), which allow you to be compact when things are trivial, explicit when they are not, or even a mix of both. You also don't have to conflate parens for priority and capture anymore, and you can create high level combinators.

For instance, this is real code to build a regex parsing URLs (translated in a JS-ish syntax):

  let cset = chars => compl(set(chars));
  let prefix = (head, tail) => char(head) ++ rep(tail);
  let scheme = rep(cset("/:?#")) ++ str("://");
  let host = rep(cset("/:?#"));
  let port = prefix(':', digit);
  let path = rep(prefix('/', cset("/?#")));
  let query = prefix('?', cset("#"));
  let fragment = prefix('#', any);
  let url = scheme ++ host ++ opt(port) ++ path ++ opt(query) ++ opt(fragment);

It's less compact, but it's still as fast and it's actually readable/maintainable. It's all the advantages of Perl's regex, without having to suffer Perl's taste in syntax.