Implement unicode on console, move readline into driver

luprex/cpp/core/drivenengine.hpp

@@ -88,10 +88,6 @@ public:
     //
     const eng::string &error() const { return error_; }
 
-    // Set the prompt for readline mode.
-    //
-    void set_prompt(const eng::string &prompt);
-
     // Do not construct your own Channels.  Instead,
     // use methods of class DrivenEngine like new_outgoing_channel.
     // Channels are referenced by shared_ptr.  You can
@@ -104,40 +100,22 @@ private:
     // Constructor is deliberately private.  Use
     // DrivenEngine::new_outgoing_channel to create outgoing socket channels.
     //
-
-    void feed_readline(std::string_view data);
     std::string_view peek_outgoing() const;
     void sent_outgoing(int nbytes);
-    void erase_command();
-    void echo_command();
-    void pump_readline();
 
 private:
-    static const int READLINE_MAX=512;
     int chid_;
 
     // These are the in/out buffers presented to the user.
     std::shared_ptr<StreamBuffer> sb_in_;
     std::shared_ptr<StreamBuffer> sb_out_;
 
-    // If this is stdio, we inject tty echoes into the output stream.
-    // This buffer holds the users output interleaved with the tty echoes.
-    // In any other channel, this is just another pointer to sb_out.
-    std::shared_ptr<StreamBuffer> sb_drvout_;
-
     int port_;
     bool closed_;
     eng::string error_;
     eng::string target_;
     bool stop_driver_;
 
-    // Readline stuff.  Only used on channel 0 (stdio).
-    eng::string desired_command_;
-    eng::string current_command_;
-    eng::string desired_prompt_;
-    eng::string current_prompt_;
-    char readline_lastc_;
-
     friend class DrivenEngine;
 };
 
@@ -215,9 +193,10 @@ public:
     // Obtain the stdio channel. There is only one stdio channel.
     //
     // DRIVER: the stdio channel is created automatically when the DrivenEngine
-    // is created.  The driver is responsible for relaying data into the channel
-    // using drv_get_target, drv_peek_outgoing, drv_sent_outgoing,
-    // drv_recv_incoming.
+    // is created.  Stdio should be connected to a console which is in
+    // line-at-a-time mode.  The driver is responsible for relaying data from
+    // the console into the stdio channel using drv_peek_outgoing,
+    // drv_sent_outgoing, drv_recv_incoming.
     //
     SharedChannel get_stdio_channel();