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List:       ruby-talk
Subject:    Re: simple XML parsing (greedy / non-greedy
From:       "Jason Voegele" <jason () jvoegele ! com>
Date:       2002-02-13 13:56:41
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> On Wed, 13 Feb 2002 12:06:49 GMT, David Alan Black
> <dblack@candle.superlink.net> wrote:
> 
>>On Wed, 13 Feb 2002, Ron Jeffries wrote:
>>> Is there a way to tell the match operator to stop on the earliest
>>> match?
>>
>>Yes -- just use *? instead of *
> 
> Thanks ... I see that that works. But I don't see why. Once the ? is in
> effect, does the whole regexp become non-greedy and quit on the first
> match? (This must be approximately the case, or it wouldn't be
> working.)

That occurrence of the * operator becomes non-greedy.  Other occurrences 
remain greedy unless followed by a '?'.

> What should I have read to know this? 

The pickaxe book has this to say (in chapter "The Ruby Language"):

"re ? 
Matches zero or one occurrence of re. The *, +, and {m,n} modifiers are 
greedy by default. Append a question mark to make them minimal."

Temporary URL while rubycentral is not available:

    http://rubycentral.rubynet.org/book/language.html

Jason Voegele



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