Re: [Boost-users] Boost regex Java Regex package compatibility

From: John Maddock (john_at_[hidden])
Date: 2007-08-16 05:07:14

Sudarshan Gaikaiwari wrote:
> Hello Boost Experts
>
> Here is my situation.
>
> Users write regular expressions which act as input to our programs and
> are used to perform matches. Currently the code base is Java and uses
> the java.util.regex package to handle regular expressions. I need to
> convert this code to C++ and intend to use boost regex.
>
> How compatible is boost regex with Java regex? I have looked at Java
> regex documentation here
> http://java.sun.com/j2se/1.5.0/docs/api/java/util/regex/Pattern.html
>
> to note the differences between Java regex and Perl 5 regexs. Are
> these the only with boost regex also?

Try comparing to the Boost.Regex reference docs here: 
http://svn.boost.org/svn/boost/trunk/libs/regex/doc/html/boost_regex/syntax/perl_syntax.html

Things I noticed are:

\u has a different meaning (use Perl-style \x{DDDDD} instead).

\p{javaLowerCase} obviously isn't supported.

\p{InGreek} isn't supported, but \p{Lu} is in the Unicode aware u32regex 
type.

X*+ not supported (as with Perl).

I'm not familiar with Java's regex package so this is almost certainly not 
definitive!

HTH, John.