From: James Edward Gray II <james@...>
Date: 2004-11-18T12:55:24+09:00
Subject: Re: Regexp bug in 1.9.0?

On Nov 17, 2004, at 9:47 PM, Francis Hwang wrote:

> Is this behavior a bug, or am I misunderstanding how I should make a 
> regexp?
>
> irb(main):001:0> str = "123.456.*"
> => "123.456.*"
> irb(main):002:0> str =~ /^[0123456789.-*]+/
> SyntaxError: compile error
> (irb):2: empty range in char class: /^[0123456789.-*]+/
>         from (irb):2
> irb(main):003:0> str =~ /^[0123456789*.-]+/
> => 0

- is a special character inside a Regexp character class.  It means, 
from this (character left of dash) to this (character right of dash).  
It's usually used to say A-Z, a-z, 0-9, or similar.  Putting it at the 
beginning or end of a class negates this special meaning, thus the 
change in the second attempt.

Did you really mean all characters from period to asterisk?

James Edward Gray II