cpp

// frontend_pyreadline.h

#ifndef FRONTEND_PYREADLINE_H

#define FRONTEND_PYREADLINE_H

#include "mycpp/runtime.h"

// hacky forward decl

namespace completion {

class ReadlineCallback;

BigStr* ExecuteReadlineCallback(ReadlineCallback*, BigStr*, int);

}  // namespace completion

// hacky forward decl

namespace comp_ui {

class _IDisplay;

void ExecutePrintCandidates(_IDisplay*, BigStr*, List<BigStr*>*, int);

}  // namespace comp_ui

namespace py_readline {

class Readline {

 public:

  Readline();

  BigStr* prompt_input(BigStr* prompt);

  void parse_and_bind(BigStr* s);

  void add_history(BigStr* line);

  void read_history_file(BigStr* path);

  void write_history_file(BigStr* path);

  void set_completer(completion::ReadlineCallback* completer);

  void set_completer_delims(BigStr* delims);

  void set_completion_display_matches_hook(

      comp_ui::_IDisplay* display = nullptr);

  BigStr* get_line_buffer();

  int get_begidx();

  int get_endidx();

  void clear_history();

  BigStr* get_history_item(int pos);

  void remove_history_item(int pos);

  int get_current_history_length();

  void resize_terminal();

  static constexpr uint32_t field_mask() {

    return maskbit(offsetof(Readline, completer_delims_)) |

           maskbit(offsetof(Readline, completer_)) |

           maskbit(offsetof(Readline, display_));

  }

  static constexpr ObjHeader obj_header() {

    return ObjHeader::ClassFixed(field_mask(), sizeof(Readline));

  }

  int begidx_;

  int endidx_;

  BigStr* completer_delims_;

  completion::ReadlineCallback* completer_;

  comp_ui::_IDisplay* display_;

  // readline will set this to NULL when EOF is received, else this will point

  // to a line of input.

  char* latest_line_;

  // readline will set this flag when either:

  //   - it receives EOF

  //   - it has a complete line of input (it has seen "\n")

  bool ready_;

};

Readline* MaybeGetReadline();

}  // namespace py_readline

#endif  // FRONTEND_PYREADLINE_H