Re: Emacs regexp scan (Sep 29)

[Paul Eggert]

On 10/5/19 1:10 AM, Eli Zaretskii wrote:
> both variants are valid, so it sounds like your personal stylistic
> preference is for the latter.  Is that the only reason?

No. The "Special Characters in Regular Expressions" subsubsection of the Elisp 
manual recommends putting '-' at the end of bracket expressions, since putting 
'-' elsewhere can cause confusion (one or two examples of which caused bugs that 
was fixed in that patch). The patch did not systematically put "-" at the end of 
every bracket expression, only those reasonably near bugs and other glitches.

> If the regexp scanner needs to be pacified, isn't it better to fix the
> scanner instead?

No, as the regexp scanner was right here: it complained about unescaped literal 
"+" in regexps, which is poor practice (and is documented as poor practice in 
the Elisp manual).

> the
> original code looks simpler to me than the new one, as the former is
> just a simple while loop, whereas the latter is a nested dolist.

Actually the old code was so confusing that it was a bit hard to see that it was 
a nested loop (not a simple while loop). I originally had the same confusion 
that you did, which is why I redid the loops to make the nesting more obvious 
and to lessen the number of lines of code.