GNU bug report logs - #37659
rx additions: anychar, unmatchable, unordered-or

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Message #13 received at 37659 <at> debbugs.gnu.org (full text, mbox):

From: Paul Eggert <eggert <at> cs.ucla.edu>
To: Mattias Engdegård <mattiase <at> acm.org>
Cc: 37659 <at> debbugs.gnu.org
Subject: Re: Mattias Engdegård <mattiase <at> acm.org>
Date: Fri, 11 Oct 2019 16:07:25 -0700

Thanks for the proposed patch. Two thoughts:

1. Instead of the symbol 'unordered-or' (which is remarkably hard to 
read), I suggest using the ASCII letter 'V'. This ASCIIfies the Unicode 
symbol U+2228 LOGICAL OR (∨). If you prefer, you could make the Unicode 
symbol an alias for 'V', or use lower-case ASCII 'v', or whatever. The 
point is that '(unordered-or A B)' is too hard to read with all those 
'or's in there.

2. Re this patch:

> -    ((or 'anychar 'anything)      (rx--translate-form '(or nonl "\n")))
> +    ((or 'anychar 'anything)      (cons (list "[^z-a]") t))

Is there a reason this uses (cons (list "[^z-a]") t) rather than 
'(("[^z-a]") . t) ? I realize neighboring code does something similar, 
but it's not clear to me why it's important to construct new objects 
here instead of using literals.

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