GNU bug report logs - #36496
[PATCH] Describe the rx notation in the lisp manual

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From: Noam Postavsky <npostavs <at> gmail.com>
To: Mattias Engdegård <mattiase <at> acm.org>
Cc: Eli Zaretskii <eliz <at> gnu.org>, 36496 <at> debbugs.gnu.org
Subject: bug#36496: [PATCH] Describe the rx notation in the lisp manual
Date: Sat, 06 Jul 2019 15:12:36 -0400

Mattias Engdegård <mattiase <at> acm.org> writes:

> Ah, you called out my little white lie. They are synonyms in practice,
> because almost nobody uses minimal-match, probably for good
> reasons. (xr used to generate {minimal|maximal}-match, but it was
> decidedly less readable so it got changed.)
>
> Yet you are right in the sense that the documentation should not lie
> or wilfully obscure the workings. There appears to be no good
> solution, because the underlying design isn't very good. It might be
> different if minimal-match affected the entire expression inside,
> including (or ...) and (** ...), but that will have to wait for the
> next big engine.
>
> The new patch versions describe the semantics more objectively, while
> still recommending the user to stay clear of minimal-match. Good
> enough?

> +(zero-or-more RX...) Match RXs zero or more times.  Alias: 0+
> +(one-or-more RX...)  Match RXs one or more times.  Alias: 1+
> +(zero-or-one RX...)  Match RXs or the empty string.  Alias: opt, optional
> +(* RX...)       Match RXs zero or more times; greedy.
> +(+ RX...)       Match RXs one or more times; greedy.
> +(? RX...)       Match RXs or the empty string; greedy.

Yep, that looks fine.

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