Re: [boost] [xpressive] Problem accessing repeating embedded pattern.

From: Bjørn Roald (bjorn_at_[hidden])
Date: 2006-01-05 18:35:52

On Thursday 05 January 2006 01:15, Eric Niebler wrote:
> Thanks for the code. I just tried it locally and it seems to work fine,
> so the bug is already fixed. The output I get is:
>
> namespace boost {
> gruble "grot}
> namespace boost {
> gruble "grot
> }
>

After CVS update I get same results :-)

> (Looks like you'll need to be smart about not matching braces that are
> in string literals.)

I use this for matching string literals:

    sregex escaped_quote = as_xpr( '\\' ) >> '"';
    sregex string_literal = as_xpr( '"' ) >> *( space |
                                                escaped_quote |
                                                -*_ ) >> '"';

seems to work, it will eat \" as part of string.  I guess it should only eat  
if there is an odd number of back-slashes prior to quote.

I tried:

    sregex escaped_quote = as_xpr( '\\' ) >> '"';
    sregex escaped_backslash = as_xpr( "\\\\" );
    sregex string_literal = as_xpr( '"' ) >> *( space |
                                                escaped_backslash |
                                                escaped_quote |
                                                -*_ ) >> '"';

But it did not work.  What are the percidence rules for the sub-elements in 
*( space |
   escaped_backslash |
   escaped_quote |
   -*_ ) 

?

Next  I try to combine that the literal string regexp  into grammar so I don't 
scan for braces within string literals.

Bjørn