From: Jeremy Hinegardner <jeremy@...>
Date: 2007-08-11T18:12:57+09:00
Subject: Re: Split a string based on change of character

On Sat, Aug 11, 2007 at 09:52:24AM +0900, Andrew Savige wrote:
> For a string "ZBBBCZZ", I want to produce a list ["Z", "BBB", "C", "ZZ"]
> That is, break the string into pieces based on change of character.
> 
> Though this works:
> 
>   s = "ZBBBCZZ"
>   x = s.scan(/((.)\2*)/).map {|i| i[0]}
> 
> I'm new to Ruby and am interested to learn if there is a better way to
> do it.
> 
> BTW, in Python, it can be done with a regex (similar to above) or via
> their itertools library:
> 
>   import itertools
>   s = "ZBBBCCZZ"
>   x = [''.join(g) for k, g in itertools.groupby(s)]
> 
> Does anyone know if Ruby has a similar library to Python's itertools?

Nothing off the top of my head, but how does this work for you ?

    in_str.split('').inject([]) do |m,l|
        if m.last and m.last[0].chr == l
            m[-1] += l
        else
            m << l
        end
        m
    end

Its not too lines, but it will return the same array

enjoy

-jeremy

-- 
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Jeremy Hinegardner                              jeremy@hinegardner.org