From: Brian Candler <B.Candler@...>
Date: 2003-04-08T00:41:20+09:00
Subject: Re: ruby-dev summary  19944 - 19957

On Tue, Apr 08, 2003 at 12:20:40AM +0900, Kazuo Saito wrote:
> They plan to change the regexp parsing rule in 1.8.0 as follows so far. 
> The plan is based on regexp coding conventions and requests from others
> in ruby-dev:
...
> 2) A literal '-' in a character class should be escaped too if the 
>    class has other '-' literals for range representation.  For instance, 
>    /[abcd-f-hijk]/ and /[--abc]/ should be written as 
>    /[abcd-f\-hijk]/ (or /[abcd\-f-hijk]/) and /[\--abc]/.
>    You can use '-' without '\' if the class has no ranges, like
>    /[-abc]/ or /[^-]/.

The way I parse regexps in my brain is the way I have been conditioned
through what I have learned with grep, awk, perl and so on :-)

I often use character classes like this:

     /[a-zA-Z0-9.-]/

which matches a-z, A-Z, 0-9, dot or dash. This is how it works everywhere
else. The rule is 'if you want to match a dash, put it at the very beginning
or very end of your character class'

I can't see any particular reason to outlaw this practice...

Regards,

Brian.