Implement more sophisticated readline-mode

luprex/core/cpp/drivenengine.hpp

@@ -144,6 +144,10 @@ public:
     //
     void set_readline(bool enabled);
 
+    // Set the prompt for readline mode.
+    //
+    void set_prompt(const std::string &prompt);
+
     // You may delete any channel except for stdio.  This closes
     // the channel.
     //
@@ -155,10 +159,11 @@ private:
     //
     Channel(DrivenEngine *de, int chid, int port, const std::string &target);
 
-    int readline_space() { return READLINE_MAX - readline_len_; }
-    int echo_space() { return READLINE_MAX - echo_len_; }
-
     void feed_readline(int nbytes, const char *bytes);
+    void peek_outgoing(int *nbytes, const char **bytes);
+    void sent_outgoing(int nbytes);
+    void show_command();
+    void hide_command();
 
 private:
     static const int READLINE_MAX=512;
@@ -170,12 +175,16 @@ private:
     bool closed_;
     std::string error_;
     std::string target_;
-    char readline_buf_[READLINE_MAX];
-    int readline_len_;
+
+    // Readline stuff.
+    std::string desired_command_;
+    std::string current_command_;
+    std::string desired_prompt_;
+    std::string current_prompt_;
+    std::string readline_echo_;
     char readline_lastc_;
-    char echo_buf_[READLINE_MAX];
-    int echo_len_;
     bool readline_enabled_;
+
     friend class DrivenEngine;
 };