parsing : extraire une information

parcourir toutes les correspondances

token : split une chaîne en sous chaines

main.cpp

    {
        std::regex pattern("(ab)cd(ef)");    // Find double word.
        std::string replacement = "le premier groupe est $1 et le second groupe est $2"; 
        std::string target = "abcdef";
        std::string output_str = regex_replace(target, pattern, replacement);
        std::cout << output_str << std::endl;
    }
    {
        std::regex pattern(R"((\d{2})[-/](\d{2})[-/](\d{4}))");
        std::smatch match;
        std::regex_search(std::string("12-03-2014"), match, pattern);
        for (size_t i = 0; i < match.size(); ++i) 
        {
            std::cout << i << ": " << match[i].str() << '\n';
        }  
    }
 
    std::cout << "Traduction" << std::endl;
    {
        std::regex pattern("([a-zA-Z]+) \\1");    
        std::string replacement = "$1";     
        std::string target = "The cat cat bites the dog dog.";
        std::string output_str = regex_replace(target, pattern, replacement);
        std::cout << output_str << std::endl;
    }
 
    std::cout << tr("bla bla $1 bla bla", 123) << std::endl;
    std::cout << tr("bli bli bli bli $1", 123) << std::endl;
    std::cout << std::endl;
 
 
    std::cout << "Groupe" << std::endl;
    match("", R"((ab)*)");
    match("a", R"((ab)*)");
    match("b", R"((ab)*)");
    match("ab", R"((ab)*)");
    match("abc", R"((ab)*)");
    match("ababab", R"((ab)*)");
    std::cout << std::endl;
 
 
    match("cat", R"(c[a-z]*t)");
    std::cout << std::endl;
 
    std::cout << "Exemples de regex" << std::endl;
    std::cout << "Date" << std::endl;
    match("12-03-2014", R"(\d{2}[-/]\d{2}[-/]\d{4})");
    std::cout << "Time" << std::endl;
    match("15:17", R"(\d{2}:\d{2})");
    std::cout << std::endl;
 
    // vérifier qu'un identifiant C++ est valide
    // [a-zA-Z_][a-zA-Z_0-9]*
 
    // fichier windows
    //[a-zA-Z_][a-zA-Z_0-9]*\.[a-zA-Z0-9]+
 
    std::string regex_str = "[a-z_][a-z_0-9]*\\.[a-z0-9]+";
    std::regex reg1(regex_str, std::regex_constants::icase);
    std::string str = "File names are readme.txt and my.cmd.";
    std::sregex_iterator it(str.begin(), str.end(), reg1);
    std::sregex_iterator it_end;
    while(it != it_end) {
        std::cout << it->str() << std::endl;
        ++it;
    }
}

Groups
le premier groupe est ab et le second groupe est ef
0: 12-03-2014
1: 12
2: 03
3: 2014
Traduction
The cat bites the dog.
bla bla 123 bla bla
bli bli bli bli 123

Groupe
"(ab)*" match with "" = true
"(ab)*" match with "a" = false
"(ab)*" match with "b" = false
"(ab)*" match with "ab" = true
"(ab)*" match with "abc" = false
"(ab)*" match with "ababab" = true

"c[a-z]*t" match with "cat" = true

Exemples de regex
Date
"\d{2}[-/]\d{2}[-/]\d{4}" match with "12-03-2014" = true
Time
"\d{2}:\d{2}" match with "15:17" = true

readme.txt
my.cmd

A déplacer dans le chapitre sur les recherches ?

main.cpp

     // non-greedy (non vorace)
    search("aaaaa", R"(a{3})");     // -> aaaaa = plus longue correspondance
    search("aaaaa", R"(a{3}?)");    // -> aaa = plus courte correspondance
    std::cout << std::endl;
}

affiche :

search "a{3}" in "aaaaa" = true
search "a{3}?" in "aaaaa" = true