From: Axel Etzold <AEtzold@...>
Date: 2007-11-25T07:54:37+09:00
Subject: Re: string matching algorithm


-------- Original-Nachricht --------
> Datum: Sun, 25 Nov 2007 07:40:50 +0900
> Von: David Weldon <dweldon@gmail.com>
> An: ruby-talk@ruby-lang.org
> Betreff: string matching algorithm

> Problem: 1 million+ strings (Set A) need to be matched with 1 million+
> substrings (Set B). For example:
> 
> Set A =
> iliketotraveltohawaii
> travelmagazine
> 
> Set B =
> travel
> hawaii
> 
> A(1,2) match "travel"
> A(1) matches "hawaii"
> 
> What is the best approach to take with this problem? I have tried using
> ferret:
> 
> http://www.ruby-forum.com/topic/132772
> 
> Indexing is fast, but search is very slow. I think ferret could be a
> good choice if I had the substrings split out so iliketotraveltohawaii
> -> "i like to travel to hawaii". I have a solution to this problem but
> it can't be trusted with misspellings (that's an entirely different
> forum topic). Is there something obvious that I'm missing here?
> -- 
> Posted via http://www.ruby-forum.com/.

Dear David,

just curious: how fast is Array#grep ?

a=%w[liketotraveltohawaii travelmagazine]
b=%w[travel hawaii]

b.each_with_index{|x,i| 
	if a.grep(x)
		puts 'entry ' + i.to_s + ' in Array a matches ' + x
        end
}

Best regards,

Axel 
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