From: James Edward Gray II <james@...>
Date: 2007-07-16T02:05:55+09:00
Subject: Re: [QUIZ] Maximum Sub-Array (#131)

On Jul 15, 2007, at 5:16 AM, Anton wrote:

> On 14/07/07, James Edward Gray II <james@grayproductions.net> wrote:
>> On Jul 14, 2007, at 12:21 PM, Anton wrote:
>>
>> > Hello, everybody! I am new here. I am also relatively new to ruby.
>> >
>> > I don't know if it's OK to ask questions here before the 48 hours
>> > period ends. So I am going to shoot straight and ask.
>> >
>> > I am trying to create a perfect regexp match string to match an  
>> array
>> > string like [1, -1, 4, 5]
>> > So far the best I've came up with is /^\[-*\d+,*.*\]$/
>> >
>> > If I add \s+ the string doesn't match. /^\[-*\d+,*\s+.*\]$/ And  
>> I have
>> > no idea why...
>>
>> Well, if I understand right, you want a regex to match an array of
>> one or more integers?  I would probably use:
>>
>>    /\A\s*\[\s*-?\d+(?:\s*,\s*-?\d+)*\s*\]\s*\Z/
>>
>> Is that what you are after?
>>
>> James Edward Gray II
>>
>
> Yes, you understood me right. Your example is what I needed. But I
> have one small question. Why is '?' needed at the beginning?
> (?:\s*,\s*-?\d+) It seems to me it's the key for a correct match :)

(?: � ) is the same as ( � ), save that it doesn't set a capture  
variable.  It's used for group elements of an expression together.

James Edward Gray II