Source code for debug_readline

#!/usr/bin/env python
'''
Script that uses IPython's prompt_toolkit to read in a line of input and echo
it out on stdout

Used by pbdb as an more advanced version of readline.
'''

import sys
from os import environ as env
import os

from pygments.lexers.shell import BashLexer
from pygments.styles import get_style_by_name

import prompt_toolkit
from prompt_toolkit.history import FileHistory
from prompt_toolkit.auto_suggest import AutoSuggestFromHistory

def main():
  if prompt_toolkit.__version__[0:2] != "1.":
    from prompt_toolkit import PromptSession
    from prompt_toolkit.lexers import PygmentsLexer
    from prompt_toolkit.styles.pygments import style_from_pygments_cls
    from prompt_toolkit.key_binding import KeyBindings


    def key_bindings():
      key_binding = KeyBindings()
      key_binding.add('enter')(return_handler)
      key_binding.add('tab')(tab_handler)
      return key_binding

    def return_handler(event):
      buffer = event.current_buffer
      # document = buffer.document
      if buffer.text.endswith("\\"):
        buffer.text=buffer.text[:-1]+'\n'
      else:
        buffer.validate_and_handle()

    def tab_handler(event):
      buffer = event.current_buffer
      document = buffer.document
      if buffer.auto_suggest:
        suggestion = buffer.auto_suggest.get_suggestion(buffer, document)
        if suggestion.text:
          buffer.text+=suggestion.text
          buffer.cursor_position+=len(suggestion.text)

    def prompt_continuation(width, line_number, is_soft_wrap):
      return ' '*(width-2) + "… "


    style = style_from_pygments_cls(get_style_by_name(env.get(
        '_debug_read_color_scheme', 'vim')))
    session = PromptSession(message=env.get('_debug_prompt', '$ '),
                            lexer=PygmentsLexer(BashLexer),
                            style=style,
                            key_bindings=key_bindings(),
                            history=FileHistory(env.get('JUST_DEBUG_HISTORY',
                                os.path.expanduser('~/.debug_bash_history'))+'3'),
                            enable_history_search=True,
                            multiline=True,
                            auto_suggest=AutoSuggestFromHistory(),
                            prompt_continuation=prompt_continuation)

    try:
      text = session.prompt()
      sys.stderr.write(text)
    except KeyboardInterrupt:
      pass
  else:
    # from __future__ import unicode_literals
    from prompt_toolkit import prompt
    from prompt_toolkit.styles import style_from_pygments
    from prompt_toolkit.layout.lexers import PygmentsLexer
    from prompt_toolkit.key_binding.manager import KeyBindingManager
    from prompt_toolkit.keys import Keys

    manager = KeyBindingManager.for_prompt()

    @manager.registry.add_binding(Keys.Enter)
    def return_handler(event):
      buffer = event.current_buffer
      if buffer.text.endswith("\\"):
        buffer.text=buffer.text[:-1]+'\n'
      else:
        buffer.accept_action.validate_and_handle(event.cli, buffer)

    @manager.registry.add_binding(Keys.Tab)
    def tab_handler(event):
      buffer = event.current_buffer
      document = buffer.document
      if buffer.auto_suggest:
        suggestion = buffer.auto_suggest.get_suggestion(event.cli, buffer, document)
        if suggestion.text:
          buffer.text+=suggestion.text
          buffer.cursor_position+=len(suggestion.text)

    style = style_from_pygments(get_style_by_name(env.get(
        '_debug_read_color_scheme', 'vim')))

    try:
      text = prompt(env.get('_debug_prompt', '$ '),
                    lexer=PygmentsLexer(BashLexer),
                    style=style,
                    key_bindings_registry=manager.registry,
                    history=FileHistory(env.get('JUST_DEBUG_HISTORY',
                                os.path.expanduser('~/.debug_bash_history'))+'3'),
                    multiline=True,
                    auto_suggest=AutoSuggestFromHistory())
      sys.stderr.write(text)
    except KeyboardInterrupt:
      pass

if __name__ == '__main__':
  main()