Parsing lines containing nested key-value pairs

src/libman/parse.cpp

@@ -81,4 +81,33 @@ void lm::write_pairs(fs::path fpath, const std::vector<pair>& pairs) {
     for (auto& pair : pairs) {
         fstream << pair.key() << ": " << pair.value() << '\n';
     }
+}
+
+nested_kvlist nested_kvlist::parse(const std::string_view line_) {
+    const auto line     = trim(line_);
+    const auto semi_pos = line.find(';');
+    const auto primary  = trim(line.substr(0, semi_pos));
+    auto       tail     = semi_pos == line.npos ? ""sv : trim(line.substr(semi_pos + 1));
+
+    std::vector<pair> pairs;
+    while (!tail.empty()) {
+        const auto space_pos = tail.find(' ');
+        const auto item      = tail.substr(0, space_pos);
+
+        const auto eq_pos = item.find('=');
+        if (eq_pos == item.npos) {
+            pairs.emplace_back(item, ""sv);
+        } else {
+            const auto key   = item.substr(0, eq_pos);
+            const auto value = item.substr(eq_pos + 1);
+            pairs.emplace_back(key, value);
+        }
+
+        if (space_pos == tail.npos) {
+            break;
+        }
+        tail = trim(tail.substr(space_pos + 1));
+    }
+
+    return nested_kvlist{std::string(primary), pair_list{std::move(pairs)}};
 }

src/libman/parse.hpp

@@ -125,6 +125,13 @@ inline void write_pairs(const std::filesystem::path& fpath, const pair_list& pai
     write_pairs(fpath, pairs.items());
 }
 
+struct nested_kvlist {
+    std::string primary;
+    pair_list   pairs;
+
+    static nested_kvlist parse(std::string_view s);
+};
+
 template <typename What>
 class read_required {
     std::string_view _key;

src/libman/parse.test.cpp

@@ -80,9 +80,52 @@ void test_multi() {
     CHECK(!iter);
 }
 
+void test_nested_kvlist() {
+    auto check_1 = [](auto str) {
+        auto result = nested_kvlist::parse(str);
+        CHECK(result.primary == "Foo");
+        CHECK(result.pairs.size() == 1);
+        REQUIRE(result.pairs.find("bar"));
+        CHECK(result.pairs.find("bar")->value() == "baz");
+    };
+    check_1("Foo; bar=baz");
+    check_1("Foo ; bar=baz");
+    check_1("Foo ;   bar=baz");
+    check_1("Foo ;   bar=baz  ");
+    check_1("Foo;bar=baz  ");
+    check_1("Foo;bar=baz");
+
+    auto check_2 = [](auto str) {
+        auto result = nested_kvlist::parse(str);
+        CHECK(result.primary == "Foo");
+        CHECK(result.pairs.size() == 0);
+    };
+    check_2("Foo");
+    check_2("Foo;");
+    check_2("Foo  ;");
+    check_2("Foo  ; ");
+    check_2("Foo; ");
+
+    auto check_3 = [](auto str) {
+        auto result = nested_kvlist::parse(str);
+        CHECK(result.primary == "Foo bar");
+        CHECK(result.pairs.size() == 2);
+        REQUIRE(result.pairs.find("baz"));
+        CHECK(result.pairs.find("baz")->value() == "meow");
+        REQUIRE(result.pairs.find("quux"));
+        CHECK(result.pairs.find("quux")->value() == "");
+    };
+
+    check_3("Foo bar; baz=meow quux");
+    check_3("Foo bar  ; baz=meow quux=");
+    check_3("Foo bar  ; quux= baz=meow");
+    check_3("Foo bar  ;quux=   baz=meow");
+}
+
 void run_tests() {
     test_simple();
     test_multi();
+    test_nested_kvlist();
 }
 
 DDS_TEST_MAIN;