I'm probably in a minority, but all I need is the Regex builder DSL as to regex; I mean I espouse "No custom literal" in the context of this pitch.
The DSL is Swifty, but regex literals aren't (in my subjective feelings).
Regex is easy to write, however, its ways to be parsed and to process strings would be more complex. I think that writing regex should be difficult in accordance with its essence (at least in Swift).
I wish regex could not break Swift even if regex literals would be accepted.