- From: Norm Tovey-Walsh <norm@saxonica.com>
- Date: Tue, 03 Feb 2026 14:12:21 +0000
- To: Steven Pemberton <steven.pemberton@cwi.nl>
- Cc: "Bethan Tovey-Walsh" <bytheway@linguacelta.com>, ixml <public-ixml@w3.org>
Steven Pemberton <steven.pemberton@cwi.nl> writes:
> The construct A!B only succeeds if A succeeds and B doesn't. Since [] never succeeds, []!digit would never succeed either. The equivalence works though for ()!digit, or ""!digit, or anything else that matches empty.
Brain cramp on my part, ()!digit will do. I’ll trade you a brain cramp, ""!digit isn’t valid because strings can’t be empty.
Be seeing you,
norm
--
Norm Tovey-Walsh
Saxonica
Received on Tuesday, 3 February 2026 14:12:27 UTC