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Regular Expressions

L1

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RegEx1.cpp
#include "Utils.hpp"
#include <clocale>
#include <codecvt>
#include <iostream>
#include <regex>
#include <string>
#include <vector>

std::locale utf8loc(std::locale(), new std::codecvt_utf8<wchar_t>);
using namespace std;

int main(int argc, char **argv) {
	setlocale(LC_ALL, "en_US.UTF-8");
	wcout.imbue(utf8loc);
	wcin.imbue(utf8loc);

	wstring const s = L"Four score and seven years ago...";
	wcout << L"Match 1: " << regex_search(s, wregex(L"s.*e")) << endl;
	wcout << L"Match 2: " << regex_search(s, wregex(L"\\bs.*e\\b")) << endl;
	wcout << L"Match 3: " << regex_search(s, wregex(L"s...e")) << endl;
	wcout << L"Match 4: " << regex_search(s, wregex(L"b.d")) << endl;

	vector<wstring> subgroups = Utils::regex_findfirst(wregex(L"(\\w+)\\s*(\\w+)"), s);
	wcout << L"Find First (with subgroups): " << Utils::to_wstring(subgroups) << endl;
	subgroups = Utils::regex_findfirst(wregex(L"bad match"), s);
	wcout << L"Find First (bad match): " << Utils::to_wstring(subgroups) << endl;

	vector<wstring> matches = Utils::regex_findall(wregex(L"\\w+"), s);
	wcout << L"Find All: (matches only)" << Utils::to_wstring(matches) << endl;
	matches = Utils::regex_findall(wregex(L"bad match"), s);
	wcout << L"Find All (bad match): " << Utils::to_wstring(matches) << endl;
	return 0;
}
Output
$ g++ -std=c++17 RegEx1.cpp -o RegEx1 -lfmt $ ./RegEx1 Match 1: 1 Match 2: 1 Match 3: 1 Match 4: 0 Find First (with subgroups): ["Four score", "Four", "score"] Find First (bad match): [] Find All: (matches only)["Four", "score", "and", "seven", "years", "ago"] Find All (bad match): []
RegEx2.cpp
#include "Utils.hpp"
#include <clocale>
#include <codecvt>
#include <iostream>
#include <regex>
#include <string>

std::locale utf8loc(std::locale(), new std::codecvt_utf8<wchar_t>);
using namespace std;

int main(int argc, char **argv) {
	setlocale(LC_ALL, "en_US.UTF-8");
	wcout.imbue(utf8loc);
	wcin.imbue(utf8loc);

	wstring const s = L"Four score and seven years ago...";
	wcout << L"Replace First 1: " << std::regex_replace(s, wregex(L"\\.\\.\\."), L"!!!", regex_constants::format_first_only) << endl;
	wcout << L"Replace First 2: " << std::regex_replace(s, wregex(L"\\b...\\b"), L"???", regex_constants::format_first_only) << endl;
	wcout << L"Replace First 3: " << std::regex_replace(s, wregex(L"b.d"), L"???", regex_constants::format_first_only) << endl;
	wcout << L"Replace First 4: " << std::regex_replace(s, wregex(L"(\\w+) (\\w+)"), L"$2 $1", regex_constants::format_first_only) << endl;

	wcout << L"Replace All 1: " << std::regex_replace(s, wregex(L"\\b...\\b"), L"???") << endl;
	wcout << L"Replace All 2: " << std::regex_replace(s, wregex(L"(\\w+) (\\w+)"), L"$2 $1") << endl;
	return 0;
}
Output
$ g++ -std=c++17 RegEx2.cpp -o RegEx2 -lfmt $ ./RegEx2 Replace First 1: Four score and seven years ago!!! Replace First 2: Four score ??? seven years ago... Replace First 3: Four score and seven years ago... Replace First 4: score Four and seven years ago... Replace All 1: Four score ??? seven years ???... Replace All 2: score Four seven and ago years...
RegEx3.cpp
#include "Utils.hpp"
#include <clocale>
#include <codecvt>
#include <iostream>
#include <regex>
#include <string>

std::locale utf8loc(std::locale(), new std::codecvt_utf8<wchar_t>);
using namespace std;

int main(int argc, char **argv) {
	setlocale(LC_ALL, "en_US.UTF-8");
	wcout.imbue(utf8loc);
	wcin.imbue(utf8loc);

	wstring const str = L"Four score and seven years ago...";
	wcout << L"Split 1: " << Utils::to_wstring(Utils::split(wregex(L" "), str)) << endl;
	wcout << L"Split 2: " << Utils::to_wstring(Utils::split(wregex(L"[eo]"), str)) << endl;
	wcout << L"Split 3: " << Utils::to_wstring(Utils::split(wregex(L"\\s"), str)) << endl;
	wcout << L"Split 4: " << Utils::to_wstring(Utils::split(wregex(L"\\W"), str)) << endl;
	return 0;
}
Output
$ g++ -std=c++17 RegEx3.cpp -o RegEx3 -lfmt $ ./RegEx3 Split 1: ["Four", "score", "and", "seven", "years", "ago..."] Split 2: ["F", "ur sc", "r", " and s", "v", "n y", "ars ag", "..."] Split 3: ["Four", "score", "and", "seven", "years", "ago..."] Split 4: ["Four", "score", "and", "seven", "years", "ago", "", ""]
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