More string manipulation

src/dds/util.hpp

 }
 
 inline bool ends_with(std::string_view s, std::string_view key) {
-    auto found = s.find(key);
+    auto found = s.rfind(key);
     return found != s.npos && found == s.size() - key.size();
 }
 
+inline bool starts_with(std::string_view s, std::string_view key) { return s.find(key) == 0; }
+
+inline bool contains(std::string_view s, std::string_view key) { return s.find(key) != s.npos; }
+
+inline std::vector<std::string> split(std::string_view str, std::string_view sep) {
+    std::vector<std::string>    ret;
+    std::string_view::size_type prev_pos = 0;
+    auto                        pos      = prev_pos;
+    while ((pos = str.find(sep, prev_pos)) != str.npos) {
+        ret.emplace_back(str.substr(prev_pos, pos - prev_pos));
+        prev_pos = pos + sep.length();
+    }
+    ret.emplace_back(str.substr(prev_pos));
+    return ret;
+}
+
 template <typename Container, typename Predicate>
 void erase_if(Container& c, Predicate&& p) {
     auto erase_point = std::remove_if(c.begin(), c.end(), p);

src/dds/util.test.cpp

+#include <dds/util.hpp>
+#include <dds/util.test.hpp>
+
+using namespace dds;
+
+namespace {
+
+#define CHECK_SPLIT(str, key, ...)                                                                 \
+    do {                                                                                           \
+        CHECK(dds::split(str, key) == std::vector<std::string>(__VA_ARGS__));                      \
+    } while (0)
+
+void test_starts_with() {
+    CHECK(starts_with("foo", "foo"));
+    CHECK(starts_with("foo.bar", "foo"));
+    CHECK(starts_with("foo", "f"));
+    CHECK(starts_with("foo", ""));
+    CHECK(starts_with("", ""));
+    CHECK(!starts_with("foo", "foot"));
+    CHECK(!starts_with("", "cat"));
+    CHECK(!starts_with("foo.bar", "bar"));
+}
+
+void test_ends_with() {
+    CHECK(ends_with("foo", "foo"));
+    CHECK(ends_with("foo.bar", "bar"));
+    CHECK(ends_with("foo", "o"));
+    CHECK(ends_with("foo", ""));
+    CHECK(ends_with("", ""));
+    CHECK(!ends_with("foo", "foot"));
+    CHECK(!ends_with("", "cat"));
+    CHECK(!ends_with("foo.bar", "foo"));
+}
+
+void test_contains() {
+    CHECK(contains("foo", "foo"));
+    CHECK(contains("foo", ""));
+    CHECK(contains("foo", "o"));
+    CHECK(!contains("foo", "bar"));
+}
+
+void test_split() {
+    CHECK_SPLIT("foo.bar", ".", {"foo", "bar"});
+    CHECK_SPLIT("foo.bar.baz", ".", {"foo", "bar", "baz"});
+    CHECK_SPLIT(".", ".", {"", ""});
+    CHECK_SPLIT("", ",", {""});
+}
+
+void run_tests() {
+    test_starts_with();
+    test_ends_with();
+    test_contains();
+    test_split();
+}
+
+}  // namespace
+
+DDS_TEST_MAIN;