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Subject: Re: [boost] Why my subexpression doesn't work in Regex
From: Qihong Wang (qihongwang_at_[hidden])
Date: 2009-03-17 23:07:13


Go you. Thanks.

Qihong

On Tue, Mar 17, 2009 at 10:43 PM, Steven Watanabe <watanabesj_at_[hidden]>wrote:

> AMDG
>
>
> Qihong Wang wrote:
>
>> I'm a new boost and regex user. I tried a c++ regex sample as follows
>>
>> regex pattern("banan\\(an\\)*a");
>> string str = "bananana";
>>
>> if(regex_match(str, pattern))
>> cout<<"---- pattern matched ----"<<endl;
>> else
>> cout<<"---- pattern unmatched ----"<<endl;
>>
>> To my surprise, the it printed out pattern unmatched. If I change str to
>> "banan(an)a",
>> the result is pattern matched. Feels like boost.Regex doesn't treat ( ) as
>> subexpression.
>> Any idea?
>>
>>
>
> You're escaping the parentheses, so Boost.Regex, treats
> them as literal "(" and ")" instead of special characters.
> The regex will match strings like
> "banan(an)))))a"
>
> In Christ,
> Steven Watanabe
>
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