From: Harry Kakueki <list.push@...>
Date: 2009-08-29T07:21:17+09:00
Subject: Re: I need a string#all_indices method--is there such a thing?

On Sat, Aug 29, 2009 at 12:05 AM, timr<timrandg@gmail.com> wrote:
> On Aug 28, 5:02 am, Harry Kakueki <list.p...@gmail.com> wrote:
>>
>> class String
>>   def all_indices(reg)
>>     idx = []
>>     (0...self.length).each{|x| idx << x if self[x..-1] =~ /\A#{reg}/}
>>     idx
>>   end
>> end
>>
>> p "this is a test string for the ts in the worldt".all_indices(/th/)
>> #> [0, 26, 36]
>> p "banana".all_indices(/ana/) #> [1, 3]
>>
>> Harry
>>
>
> This works and the code is more concise than what I had, but it is a
> brute force approach that test for matches from every possible
> substring. That would be a bit slow.
>
>

This is not fast enough?

class String
  def all_indices(reg)
    idx = []
    (0...self.length).each{|x| idx << x if self[x..-1] =~ /\A#{reg}/}
    idx
  end
end

p ("this is a test string for the ts in the worldt"*1000).all_indices(/th/)

I guess you are processing some big strings.
Speed is not what you asked for.
Well, until now :)


Harry

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