Re: [Boost-users] [xpressive] Pattern problems (newbie)

From: Eric Niebler (eric_at_[hidden])
Date: 2008-02-14 18:04:30

ope wrote:
> Hi,
> 
> I'try to build a regex for an ibis file, the line I'm interested looks like:
> 
> [IBIS Ver]      3.2   | Used for template variations"
> 
> where '|' is an optional comment identifier with the (therefore 
> optional) comments follows. I'm interested in the version self: "3.2" to 
>    create a parser using a factory.
> 
> Using egrep '^\[IBIS Ver]' success.
> 
>  From docs I tested the dynamic regex
> 
> $ perl -p -e '(\\w+) (\\w+)!' "Hello World"
> 
> which fails  (syntax error at -e line 1, near "+) ")

This isn't really an xpressive question, is it? In perl, regexes must be 
enclosed in forward slashes. Try: /(\w+) (\w+)!/. But that's not how it 
works in C++.

> The regex are perl syntax, isn't? What is the regex for my IBIS Ver 
> identifier?

In C++ or in perl? The regex would look something like: \[IBIS 
Ver\]\s+((\d+)\.(\d+))

In C++ you would double up the backslashes. In perl, you'd surround it 
in forward slashes.

HTH,

-- 
Eric Niebler
Boost Consulting
www.boost-consulting.com