Introduction

libregex is a regular expression engine that can match multiple expressions simultaneously.

API

At the heart of the API are the find() and match() functions.

The match() functions require that the expression(s) match the entire input, whereas the find() functions scan the input until the first match is found.

namespace regex
{
    // Find the left-most match in the string
    bool find(const std::string& s, expression& re);

    // Read from the input stream until EOS or a match is found
    bool find(std::istream* is, expression& re);

    // Try to match the expression against the entire string
    bool match(const std::string& s, const expression& re);

    // Try to match the expression against the input stream
    bool match(std::istream& is, expression& re);

    // Find the left-most matching expressions in the string
    expressions* find(const std::string& s, expressions& regexs);

    // Read from the input stream until EOS or a match is found
    expressions* find(std::istream& is, expressions& regexs);

    // Return the expressions that match the entire input string
    expressions* match(const std::string& s, expressions& regexs);

    // Return the expressions that match the input stream
    expressions* match(std::istream& is, expressions& regexs);
}

Example

This simple example scans two strings looking for the expression 'abc' and prints the results to the console.

#include <string>
#include "regex/regex.h"

int main()
{
    std::string s1("a");
    std::string s2("abc");

    regex::literal l1("abc");

    printf("'%s' %s 'a'
", s1.c_str(), regex::match(s1, l1) ? "==" : "!=");
    printf("'%s' %s 'a'
", s2.c_str(), regex::match(s2, l1) ? "==" : "!=");

    return 0;
}