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

[Eli Zaretskii]

> From: Andy Moreton <andrewjmoreton@gmail.com>
> Date: Tue, 11 Jun 2019 20:56:09 +0100
> 
> The docs for [:digit:] and [:xdigit:] seem clear enough, but there is
> one other minor point that could be clarified.
> 
> The [:alnum:] and [:alpha:] are based on (unspecified values of) the Unicode
> general-category property, but [:digit:] is not. Thus [:alnum:] includes
> other numeric characters that are not matched by [:digit:].

It's true that [:alnum:] includes more numerical characters that
[:digit:], but what exactly needs to be clarified here?  Assuming you
mean clarified in the manual, that is.