mu-regex: add match_groups, use everywhere

Add match_groups to Mu::Regex, and update old "raw" GRegex users.

lib/utils/mu-regex.cc

@@ -61,6 +61,69 @@ test_regex_match2()
 }
 
 
+static void
+test_regex_match_groups()
+{
+	{
+		auto rx = Regex::make("^(\\d+)-(\\w+)$");
+		assert_valid_result(rx);
+
+		const auto groups{rx->match_groups("123-abc")};
+		g_assert_true(!!groups);
+		g_assert_cmpuint(groups->size(), ==, 3);
+		assert_equal(groups->at(0), "123-abc");
+		assert_equal(groups->at(1), "123");
+		assert_equal(groups->at(2), "abc");
+
+		// no match -> Nothing
+		g_assert_false(!!rx->match_groups("nope"));
+	}
+
+	{ // always capture-count + 1 elements; a trailing group that
+	  // did not participate is an empty string
+		auto rx = Regex::make("^(\\d+)(k|m|g)?$", G_REGEX_CASELESS);
+		assert_valid_result(rx);
+
+		const auto groups{rx->match_groups("512")};
+		g_assert_true(!!groups);
+		g_assert_cmpuint(groups->size(), ==, 3);
+		assert_equal(groups->at(1), "512");
+		assert_equal(groups->at(2), "");
+
+		const auto groups2{rx->match_groups("512K")};
+		g_assert_true(!!groups2);
+		g_assert_cmpuint(groups2->size(), ==, 3);
+		assert_equal(groups2->at(2), "K");
+	}
+
+	{ // a non-participating group in the middle
+		auto rx = Regex::make("^(?:(a)|(b))(c)$");
+		assert_valid_result(rx);
+
+		const auto groups{rx->match_groups("bc")};
+		g_assert_true(!!groups);
+		g_assert_cmpuint(groups->size(), ==, 4);
+		assert_equal(groups->at(1), "");
+		assert_equal(groups->at(2), "b");
+		assert_equal(groups->at(3), "c");
+	}
+
+	{ // no capture groups at all -> just the full match
+		auto rx = Regex::make("b.c");
+		assert_valid_result(rx);
+
+		const auto groups{rx->match_groups("abxcd")};
+		g_assert_true(!!groups);
+		g_assert_cmpuint(groups->size(), ==, 1);
+		assert_equal(groups->at(0), "bxc");
+	}
+
+	{ // unset rx matches nothing
+		Regex rx;
+		g_assert_false(!!rx.match_groups("foo"));
+	}
+}
+
 static void
 test_regex_replace()
 {
@@ -105,6 +168,7 @@ main(int argc, char* argv[])
 
 	g_test_add_func("/regex/match", test_regex_match);
 	g_test_add_func("/regex/match2", test_regex_match2);
+	g_test_add_func("/regex/match-groups", test_regex_match_groups);
 	g_test_add_func("/regex/replace", test_regex_replace);
 	g_test_add_func("/regex/fail", test_regex_fail);
 

lib/utils/mu-regex.hh

@@ -1,5 +1,5 @@
 /*
-** Copyright (C) 2022-2023 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
+** Copyright (C) 2022-2026 Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>
 **
 ** This program is free software; you can redistribute it and/or modify it
 ** under the terms of the GNU General Public License as published by the
@@ -30,10 +30,6 @@ namespace Mu {
  * PCRE rather than std::regex because it is much faster.
  */
 struct Regex {
-#if !GLIB_CHECK_VERSION(2,74,0) /* backward compat */
-#define G_REGEX_DEFAULT	      (static_cast<GRegexCompileFlags>(0))
-#define G_REGEX_MATCH_DEFAULT (static_cast<GRegexMatchFlags>(0))
-#endif
 	/**
 	 * Trivial constructor
 	 *
@@ -144,6 +140,42 @@ struct Regex {
 		// the str.c_str(). It *seems* like a false alarm.
 	}
 
+	/**
+	 * Match this regexp against the given string and return the captured
+	 * groups.
+	 *
+	 * Element 0 is the full match, element n corresponds with the n-th
+	 * capture group in the pattern. The result always has capture-count +
+	 * 1 elements; groups that did not participate in the match are empty
+	 * strings.
+	 *
+	 * @param str string to match
+	 * @param mflags match flags
+	 *
+	 * @return the captured groups, or Nothing if there was no match (or no
+	 * valid regexp)
+	 */
+	Option<std::vector<std::string>>
+	match_groups(const std::string& str,
+		     GRegexMatchFlags mflags=G_REGEX_MATCH_DEFAULT) const {
+		GMatchInfo *minfo{};
+		if (!rx_ || !g_regex_match(rx_, str.c_str(), mflags, &minfo)) {
+			g_clear_pointer(&minfo, g_match_info_unref);
+			return Nothing;
+		}
+
+		std::vector<std::string> groups;
+		groups.reserve(g_regex_get_capture_count(rx_) + 1);
+		for (int i = 0; i != g_regex_get_capture_count(rx_) + 1; ++i) {
+			auto&& grp{g_match_info_fetch(minfo, i)};
+			groups.emplace_back(grp ? grp : "");
+			g_free(grp);
+		}
+		g_match_info_unref(minfo);
+
+		return Some(std::move(groups));
+	}
+
 	/**
 	 * Replace all occurrences of @this regexp in some string with a
 	 * replacement string

lib/utils/mu-utils.cc

@@ -44,6 +44,7 @@
 #include <glib/gprintf.h>
 
 #include "mu-utils.hh"
+#include "mu-regex.hh"
 #include "mu-unbroken.hh"
 
 #include "mu-error.hh"
@@ -538,43 +539,31 @@ Mu::parse_date_time(const std::string& dstr, bool is_first, bool utc)
 Option<int64_t>
 Mu::parse_size(const std::string& val, bool is_first)
 {
-	int64_t		size{-1};
-	std::string	str;
-	GRegex*		rx;
-	GMatchInfo*	minfo;
-
 	/* one-sided ranges */
 	if (val.empty())
 		return is_first ? 0 : std::numeric_limits<int64_t>::max();
 
-	rx = g_regex_new("^(\\d+)(b|k|kb|m|mb|g|gb)?$",
-			 G_REGEX_CASELESS, (GRegexMatchFlags)0, NULL);
-	minfo = NULL;
-	if (g_regex_match(rx, val.c_str(), (GRegexMatchFlags)0, &minfo)) {
+	static const auto rx =
+		unwrap(Regex::make("^(\\d+)(b|k|kb|m|mb|g|gb)?$", G_REGEX_CASELESS));
 
-		char*  s = g_match_info_fetch(minfo, 1);
-		size = atoll(s); // check overflow?
-		g_free(s);
+	const auto groups{rx.match_groups(val)};
+	if (!groups)
+		return Nothing;
 
-		s = g_match_info_fetch(minfo, 2);
-		switch (s ? g_ascii_tolower(s[0]) : 0) {
-		case 'k': size *= 1024; break;
-		case 'm': size *= (1024 * 1024); break;
-		case 'g': size *= (1024 * 1024 * 1024); break;
-		default: break;
-		}
+	int64_t size{::atoll(groups->at(1).c_str())}; // check overflow?
 
-		g_free(s);
+	const auto& unit{groups->at(2)};
+	switch (unit.empty() ? 0 : g_ascii_tolower(unit.at(0))) {
+	case 'k': size *= 1024; break;
+	case 'm': size *= (1024 * 1024); break;
+	case 'g': size *= (1024 * 1024 * 1024); break;
+	default: break;
 	}
 
-	g_regex_unref(rx);
-	g_match_info_unref(minfo);
-
 	if (size < 0)
 		return Nothing;
 	else
 		return size;
-
 }
 
 std::string