From: Todd Benson <caduceass@...>
Date: 2008-05-09T08:30:36+09:00
Subject: Re: Doing an AND in regexp char class

On Thu, May 8, 2008 at 6:07 PM, ara.t.howard <ara.t.howard@gmail.com> wrote:
>
> On May 8, 2008, at 3:40 PM, Todd Benson wrote:
>>
>> This question arises out of a couple of recent threads and may or may
>> not be a Ruby-specific question.
>>
>> I can check with a character class if one of the characters in the
>> class exists or does not exist, but can I use a regexp to check if a
>> string absolutely contains all of the characters in the class?
>>
>> Using a set perspective, I can do it like this in irb...
>>
>> s1 = "hello there"
>> s2 = "ohi"
>> (s2.unpack('c*') & s1.unpack('c*')).size == s2.size
>>
>> => false
>>
>> I use unpack to avoid creating a bunch of String objects, one for each
>> element in the array, which would happen if I used #split.  What I'm
>> wondering is if there is a way to do this with a simple regexp.
>>
>> Thanks,
>> Todd
>
> cfp:~ > cat a.rb
> class String
>  def all_chars? chars
>    tr(chars, '').empty?
>  end
> end
>
> p 'foobar'.all_chars?('rabof')
> p 'foobar'.all_chars?('abc')
> p 'foobar'.all_chars?('')
>
>
>
> cfp:~ > ruby a.rb
> true
> false
> false

Cool :)  #tr is one of those useful methods I somehow consistently forget about.

tkx fur realizashuns,
Todd