doc: add API documentation

1 files changed, 16 insertions, 0 deletions

diff --git a/ttwhy/terminal/echo.cppm b/ttwhy/terminal/echo.cppm
index 660cf42..6f1ac2e 100644
--- a/ttwhy/terminal/echo.cppm
+++ b/ttwhy/terminal/echo.cppm
@@ -27,23 +27,39 @@ namespace ttwhy::terminal
   constexpr auto vte_cursor_left_sequence_format = "\x1b[{}D"sv;
   constexpr auto vte_cursor_right_sequence_format = "\x1b[{}C"sv;
 
+  //! An asynchronous router that echoes characters and handles terminal navigation.
+  //!
+  //! @tparam StreamType The output stream descriptor type.
   export template<typename StreamType>
   struct echo
   {
+    //! Construct an echo router writing to an output stream.
+    //!
+    //! @param stream The output stream to write echoed text and escape sequences to.
     explicit echo(StreamType & stream)
         : m_output_stream{stream}
     {}
 
+    //! Get the current cursor position within the printed line.
+    //!
+    //! @return The zero-based cursor position.
     [[nodiscard]] auto cursor_position() const noexcept -> std::size_t
     {
       return m_cursor_position;
     }
 
+    //! Get the maximum cursor position reached on the current line.
+    //!
+    //! @return The maximum position reached.
     [[nodiscard]] auto max_position() const noexcept -> std::size_t
     {
       return m_max_position;
     }
 
+    //! Asynchronously process an incoming terminal input event.
+    //!
+    //! @param event The input event to handle.
+    //! @return An awaitable task that completes when processing finishes.
     auto process(input_event event) -> asio::awaitable<void>
     {
       co_await std::visit(