From ea83031a285f9c1097af7bfafcb1318315e32742 Mon Sep 17 00:00:00 2001 From: Tony Garnock-Jones Date: Mon, 4 Oct 2021 14:29:39 +0200 Subject: [PATCH] Notes on regex dialect --- preserves-path.md | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/preserves-path.md b/preserves-path.md index 40cc197..5db1fd4 100644 --- a/preserves-path.md +++ b/preserves-path.md @@ -99,6 +99,17 @@ Filters: narrow down a selection without moving dict embedded +Design choice: Which regular expression dialect to choose? [CDDL (RFC +8610) goes for XML Schema regular +expressions](https://www.rfc-editor.org/rfc/rfc8610.html#section-3.8.3), +which seems like a very sensible choice. The discussion in section +3.8.3 of RFC 8610 makes some good points. A couple of things that +occurred to me: (1) the dialect should be backreference-free, allowing +matching by "[text-directed +engines](https://www.regular-expressions.info/engine.html)"; (2) it +should be very widely implemented; (3) it should cover regular +languages and no more; (4) it should be easy to implement. + ## Transformers e.g. stringify results; sequenceify results (see "+" operator); setify