From: Todd Benson <caduceass@...>
Date: 2008-05-09T11:09:15+09:00
Subject: Re: Doing an AND in regexp char class

On Thu, May 8, 2008 at 7:26 PM, Joel VanderWerf <vjoel@path.berkeley.edu> wrote:
> Todd Benson wrote:
>>
>> I'm drawing a blank here with this one.  Why doesn't this work then...
>>
>> irb(main):006:0> r = /\A[oh]*\z/
>> => /\A[oh]*\z/
>> irb(main):007:0> s = "hello, there"
>> => "hello, there"
>> irb(main):008:0> r === s
>> => false
>
> Maybe I'm confused about was wanted originally. The above tests the
> following condition:
>
>  (set of chars occurring in given string)
>     is_a_subset_of
>  (given set of chars).

Yep.  The subject title is misleading, because the AND is already
there [^ho] means not h _and_ also not o.

I was looking to find if given a string A, can I say whether or not
all of the characters in string A exist in string B (count doesn't
matter, just existence).  All of you gave me some good answers that I
hadn't thought of.  Good brain food :-)

Todd