Move types into types.hpp and add answer_type::next() and prev().

include/connection.hpp

@@ -17,10 +17,10 @@
 #ifndef MASTODONPP_CONNECTION_HPP
 #define MASTODONPP_CONNECTION_HPP
 
-#include "answer.hpp"
 #include "api.hpp"
 #include "curl_wrapper.hpp"
 #include "instance.hpp"
+#include "types.hpp"
 
 #include <string>
 #include <string_view>

include/curl_wrapper.hpp

@@ -17,28 +17,20 @@
 #ifndef MASTODONPP_CURL_WRAPPER_HPP
 #define MASTODONPP_CURL_WRAPPER_HPP
 
-#include "answer.hpp"
+#include "types.hpp"
 
 #include "curl/curl.h"
 
-#include <map>
 #include <mutex>
 #include <string>
 #include <string_view>
-#include <utility>
-#include <variant>
-#include <vector>
 
 namespace mastodonpp
 {
 
-using std::map;
 using std::mutex;
 using std::string;
 using std::string_view;
-using std::pair;
-using std::variant;
-using std::vector;
 
 /*!
  *  @brief  The HTTP method.
@@ -54,36 +46,6 @@ enum class http_method
     DELETE
 };
 
-/*!
- *  @brief  `std::map` of parameters for %API calls.
- *
- *  Note that arrays always have to be specified as vectors, even if they have
- *  only 1 element. To send a file, use “<tt>\@file:</tt>” followed by the file
- *  name as value.
- *
- *  Example:
- *  @code
- *  parametermap parameters
- *      {
- *          {"poll[expires_in]", "86400"},
- *          {"poll[options]", vector<string_view>{"Yes", "No", "Maybe"}},
- *          {"status", "How is the weather?"}
- *      };
- *  @endcode
- *
- *  @since  0.1.0
- */
-using parametermap =
-    map<string_view, variant<string_view, vector<string_view>>>;
-
-/*!
- *  @brief  A single parameter of a parametermap.
- *
- *  @since  0.1.0
- */
-using parameterpair =
-    pair<string_view, variant<string_view, vector<string_view>>>;
-
 /*!
  *  @brief  Handles the details of network connections.
  *

include/instance.hpp

@@ -18,7 +18,7 @@
 #define MASTODONPP_INSTANCE_HPP
 
 #include "curl_wrapper.hpp"
-#include "answer.hpp"
+#include "types.hpp"
 
 #include <cstdint>
 #include <string>

include/mastodonpp.hpp

@@ -17,11 +17,11 @@
 #ifndef MASTODONPP_HPP
 #define MASTODONPP_HPP
 
-#include "answer.hpp"
 #include "api.hpp"
 #include "connection.hpp"
 #include "exceptions.hpp"
 #include "instance.hpp"
+#include "types.hpp"
 
 /*!
  *  @headerfile mastodonpp.hpp mastodonpp/mastodonpp.hpp

include/types.hpp

@@ -14,22 +14,62 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef MASTODONPP_ANSWER_HPP
-#define MASTODONPP_ANSWER_HPP
+// Types that are used in more than one file.
+
+#ifndef MASTODONPP_TYPES_HPP
+#define MASTODONPP_TYPES_HPP
 
 #include <cstdint>
+#include <map>
 #include <ostream>
 #include <string>
 #include <string_view>
+#include <utility>
+#include <variant>
+#include <vector>
 
 namespace mastodonpp
 {
 
 using std::uint8_t;
 using std::uint16_t;
+using std::map;
 using std::ostream;
 using std::string;
 using std::string_view;
+using std::pair;
+using std::variant;
+using std::vector;
+
+/*!
+ *  @brief  `std::map` of parameters for %API calls.
+ *
+ *  Note that arrays always have to be specified as vectors, even if they have
+ *  only 1 element. To send a file, use “<tt>\@file:</tt>” followed by the file
+ *  name as value.
+ *
+ *  Example:
+ *  @code
+ *  parametermap parameters
+ *      {
+ *          {"poll[expires_in]", "86400"},
+ *          {"poll[options]", vector<string_view>{"Yes", "No", "Maybe"}},
+ *          {"status", "How is the weather?"}
+ *      };
+ *  @endcode
+ *
+ *  @since  0.1.0
+ */
+using parametermap =
+    map<string_view, variant<string_view, vector<string_view>>>;
+
+/*!
+ *  @brief  A single parameter of a parametermap.
+ *
+ *  @since  0.1.0
+ */
+using parameterpair =
+    pair<string_view, variant<string_view, vector<string_view>>>;
 
 /*!
  *  @brief  Return type for Request%s.
@@ -110,9 +150,48 @@ struct answer_type
      *
      *  @since  0.1.0
      */
+    [[nodiscard]]
     string_view get_header(string_view field) const;
+
+    /*!
+     *  @brief  Returns the parameters needed for the next entries.
+     *
+     *  Parses the `Link` header.
+     *
+     *  @since  0.3.0
+     */
+    [[nodiscard]]
+    inline parametermap next() const
+    {
+        return parse_pagination(true);
+    }
+
+    /*!
+     *  @brief  Returns the parameters needed for the previous entries.
+     *
+     *
+     *  Parses the `Link` header.
+     *
+     *  @since  0.3.0
+     */
+    [[nodiscard]]
+    inline parametermap prev() const
+    {
+        return parse_pagination(false);
+    }
+
+private:
+    /*!
+     *  @brief  Returns the parameters needed for the next or previous entries.
+     *
+     *
+     *  Parses the `Link` header.
+     *
+     *  @since  0.3.0
+     */
+    parametermap parse_pagination(bool next) const;
 };
 
 } // namespace mastodonpp
 
-#endif  // MASTODONPP_ANSWER_HPP
+#endif  // MASTODONPP_TYPES_HPP

src/instance.cpp

@@ -14,7 +14,6 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "answer.hpp"
 #include "instance.hpp"
 #include "log.hpp"
 

src/types.cpp

@@ -14,7 +14,8 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "answer.hpp"
+#include "log.hpp"
+#include "types.hpp"
 
 #include <algorithm>
 #include <cctype>
@@ -60,4 +61,40 @@ string_view answer_type::get_header(const string_view field) const
     return {};
 }
 
+parametermap answer_type::parse_pagination(const bool next) const
+{
+    const string_view link{get_header("Link")};
+    if (link.empty())
+    {
+        return {};
+    }
+
+    const auto direction{next ? R"(rel="next")" : R"(rel="prev")"};
+    auto endpos{link.find(direction)};
+    endpos = link.rfind('>', endpos);
+    auto startpos{link.rfind('?', endpos) + 1};
+    const string_view paramstr{link.substr(startpos, endpos - startpos)};
+    debuglog << "Found parameters in Link header: " << paramstr << '\n';
+
+    startpos = 0;
+    parametermap parameters;
+    while ((endpos = paramstr.find('=', startpos)) != string_view::npos)
+    {
+        parameterpair param;
+        param.first = paramstr.substr(startpos, endpos - startpos);
+        startpos = endpos + 1;
+        endpos = paramstr.find('&', startpos);
+        param.second = paramstr.substr(startpos, endpos - startpos);
+        parameters.insert(param);
+
+        if (endpos == string_view::npos)
+        {
+            break;
+        }
+        startpos = endpos + 1;
+    }
+
+    return parameters;
+}
+
 } // namespace mastodonpp