Re: [Boost-users] [Spirit-general] Pattern matching with boost

I have a larger code-base, in which I have restricted possible matches to 4 std::string. Basically all I know is there MIGHT exists a name1 with form name1->number1, in s1 where name1 == name1 in s3 where s3 contains name1->number1+2. Perhaps look at a s5 (number1+4) to confirm pattern. IF a pattern like this exists, return s1.substr(<whatever the mathed area is>) (sorry if I didn't explain this clearer before) How would I do this in boost? Thanks for all suggestions, Alec Taylor On Thu, Nov 10, 2011 at 3:33 PM, Anthony Foiani wrote:

Alec Taylor writes:

...

Would it be possible to abstract away the terms "apple" and "cheese" to just equal anything with that pattern?

So like this:

s1=name1-> consecutive-number s2= consecutive-number->name2 s3=name1->consecutive-number s4=consecutive-number->name2

Just what pattern do you mean, though?  You've used "name" and "string1".  Is there a character class or other short regexp that would match what you mean by "name" below?

And do you already have the 4 strings, or are you scanning a continuous piece of text?  If the latter, you're suddenly in the realm of wanting a state machine (because if s4 fails to match, then might have to consider s3 the new s1 and s4 the new s2...)

Is "consecutive" only within the 4 strings, or is it actually cumulative from some other value?  (This is a big part of what makes this difficult to do with boost or any other C/C++-based RE engine. Perl allows one to actually do evaluation within the search string, so you really could match this all with a single RE there -- but it'd be ugly, and I don't really know how efficient it would be.)

Curious, T.