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Datum: Sun, 03 Feb 2013 07:35:43 +0800 Von: Joel de Guzman An: boost-users@lists.boost.org Betreff: Re: [Boost-users] [qi] parser stocks inside an endless loop

On 2/2/13 9:01 PM, Boost_mailinglist@gmx.de wrote:

...

Hello,

the attached example will stock inside an endless loop if I use

/*loop*/ Variable = *char_("a-zA-Z_0-9")>> ...

but works if I use

/*works*/ Variable = &char_("a-zA-Z")>> *char_("a-zA-Z_0-9")>> ...

or

/*works also*/ Variable = +char_("a-zA-Z_0-9")>> ... .

Why does it happen? And how can I prevent this behaviour?

Keep in mind that *p will match p *zero* or more times. In other words, it will always match and will even match the empty string.

Regards, -- Joel de Guzman http://www.boostpro.com http://boost-spirit.com

Thank you for the response. Sometimes you need one, who shows you the point you have missed. Thanks.