From: Sebastian Hungerecker <sepp2k@...>
Date: 2008-08-06T16:52:21+09:00
Subject: Re: Strange result using String#split

Ryan Wallace wrote:
> "text_search '(large red spear OR axe) AND wood' AND material
> 1".split( /(?: AND )?(\S+ '.+')(?: AND )?|(?: AND )/ )
>
> gives:
>
> ["", "text_search '(large red spear OR axe) AND wood'", "material 1"]
>
> I don't understand why my regular expression is producing the blank
> entry at the beginning of the array. Can anyone lend some insight?

"text_search '(large red spear OR axe) AND wood'" is what your regex matches.
"" is what comes before the match and "material 1" is what comes after the 
match. If a split-regex matches the beginning of a string, the first item in 
the returned array will be "". Compare:
>> "a1b".split(/1/)
=> ["a", "b"]
>> "1b".split(/1/)
=> ["", "b"]
>> "1b".split(/(1)/)
=> ["", "1", "b"]

I also notice that you have a greedy quantifier between the '' in the regex. 
This will likely cause unwanted result when you have more than one pair of '' 
in your string.

HTH,
Sebastian
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