From: Alex Young <alex@...>
Date: 2006-05-06T04:25:53+09:00
Subject: Re: Newbie question

Kyle Alons wrote:
> James Gray wrote:
> 
>> >> ["&abc", "a&cb", "b&ac", "ccc", "cb&a"].grep(/&../)
>>=> ["&abc", "a&cb", "b&ac"]
>>
>>Hope that helps.
> 
> 
> That's not quite it.  That seems to match all strings containing an 
> ampersand followed by 2 other characters.  What I need is all strings 
> that have duplicate characters following an & (&a in the above). 
> Something a little more concrete:
> 
> ["&File", "&Edit", "Vi&ew", "P&roject", "T&ree", "Favo&rites", "&Help"]
> 
> would return
> 
> ["&Edit", "Vi&ew", "P&roject", "T&ree", "Favo&rites"]
> 
> (&e and &r are found multiple times).
> 

keys = {}

["&File", "&Edit", "Vi&ew", "P&roject", "T&ree", "Favo&rites", 
"&Help"].each do |l|
   l =~ /&(.)/
   (keys[ $1.downcase ] ||= []) << l
end

keys.values.select{|l| l.length > 1}.flatten

There's almost certainly a better way...

-- 
Alex