How parse a string in C++

Question

I want to parse the strings, so that to check whether they have specified syntax or not.

Example:

Str = Z344-R565l t

Here my requirement is after Z there should be a number and after that a - and after that R should be there followed by a number, followed by l, followed by a space and then finally t.

If any thing other than this it should be a error.

I have to parse many different kind of syntax like this. I would be awkward if write a function for each type of syntax required. I heard that yacc or lex can solve this problem.

Can any one please throw some light on my problem?

Answer 1

Use boost::regex

#include <string>
#include <boost/regex.hpp>

bool isMatch(std::string input){
    boost::regex r("Z[0-9]*-R[0-9]*l t");
    return boost::regex_search(input, r);
}

The other thing that you could do is supply a list of regex expressions in a file, one expression per line. Create a vector of boost::regex objects using the file input and iterate through the vector of patterns for each string you need to validate. It's not very efficient but it will work.