bug#36167: [PATCH] Replace manually crafted hex regexes with [[:xdigit:]]

[Mattias Engdegård]

11 juni 2019 kl. 17.37 skrev Paul Eggert <eggert@cs.ucla.edu>:
> 
> No, it's basically the same thing; we're looking for any place that 
> [:xdigit:] would be useful in clarifying patterns intended to max hexadecimal 
> digits (and perhaps some other things). Also, the skip-chars arguments are 
> also the same thing. Let's do all these.

Since you asked, I've attached a relint run with xr modified to find parts of 
character alternatives and skip-sets that could be replaced with [:xdigit:], on 
Emacs .el files in master; it was quick work.

However, I'm not really convinced that the risks of making mistakes in the 
translation would outweigh the benefits. We could make an automatic 
verification, but [0-9A-Fa-f] still has one advantage: the reader, and the 
writer, know exactly which characters are included without looking it up. For 
example:

- whether upper case, lower case, or both are accepted
- whether non-ascii digits are accepted (included in [:digit:] on many 
platforms)

But it's not up to me; should your judgement tell you otherwise, go ahead! I 
don't mind the use of [:xdigit:] at all, it's just the wholesale replacement.

xdigit.log
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