From: timr <timrandg@...>
Date: 2009-08-29T00:00:05+09:00
Subject: Re: I need a string#all_indices method--is there such a thing?

On Aug 28, 2:01 am, Robert Dober <robert.do...@gmail.com> wrote:
> On Fri, Aug 28, 2009 at 10:25 AM, timr<timra...@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)

Oh, tap is new in 1.9. Sorry, I hadn't come across it before and was
in 1.8.6 so it wasn't running. Got it now.