From: Robert Dober <robert.dober@...>
Date: 2009-08-28T18:01:22+09:00
Subject: Re: I need a string#all_indices method--is there such a thing?

On Fri, Aug 28, 2009 at 10:25 AM, timr<timrandg@gmail.com> wrote:
> In ruby you can use string#index as follows:
> str = "some text"
> str.index(/t/)
> =>5
>
> But what if I want to get all the indices for a regex in the string?
> Is there an string#all_indices method?
>
> I wrote the following, which works, but there must be a more elegant
> way:
>
> class String
>  def all_indices(regex)
>  indices = []
>  index = 0
>    while index && index < self.length #index will be nil upon first
> match failure, otherwise quit loop when index is equal to string
> length
>      index = self.index(regex, index)
>      if index.is_a? Numeric   #avoids getting a nil into the indices
> array
>        indices << index
>        index +=1
>      end
>    end
>    indices
>  end
> end
> p "this is a test string for the ts in the worldt".all_indices(/t/)
> p "what is up with all the twitter hype".all_indices(/w/)
> # >> [0, 10, 13, 16, 26, 30, 36, 45]
> # >> [0, 11, 25]
>
>
What about
class String
  def indices rgx, idx=0
    [].tap{ |r|
      loop do
        idx = index rgx, idx
        break unless idx
        r << idx
        idx += 1
      end
    }
  end
end

p "baaababbabbbba".indices( /a/ )



-- 
If you tell the truth you don't have to remember anything.
--
Samuel Clemens (some call him Mark Twain)