def load_emacs_bindings():
    """
    Some e-macs extensions.
    """
    # Overview of Readline emacs commands:
    # http://www.catonmat.net/download/readline-emacs-editing-mode-cheat-sheet.pdf
    registry = ConditionalRegistry(Registry(), EmacsMode())
    handle = registry.add_binding

    insert_mode = EmacsInsertMode()
    has_selection = HasSelection()

    @handle(Keys.Escape)
    def _(event):
        """
        By default, ignore escape key.

        (If we don't put this here, and Esc is followed by a key which sequence
        is not handled, we'll insert an Escape character in the input stream.
        Something we don't want and happens to easily in emacs mode.
        Further, people can always use ControlQ to do a quoted insert.)
        """
        pass

    handle(Keys.ControlA)(get_by_name('beginning-of-line'))
    handle(Keys.ControlB)(get_by_name('backward-char'))
    handle(Keys.ControlDelete, filter=insert_mode)(get_by_name('kill-word'))
    handle(Keys.ControlE)(get_by_name('end-of-line'))
    handle(Keys.ControlF)(get_by_name('forward-char'))
    handle(Keys.ControlLeft)(get_by_name('backward-word'))
    handle(Keys.ControlRight)(get_by_name('forward-word'))
    handle(Keys.ControlX, 'r', 'y', filter=insert_mode)(get_by_name('yank'))
    handle(Keys.ControlY, filter=insert_mode)(get_by_name('yank'))
    handle(Keys.Escape, 'b')(get_by_name('backward-word'))
    handle(Keys.Escape, 'c', filter=insert_mode)(get_by_name('capitalize-word'))
    handle(Keys.Escape, 'd', filter=insert_mode)(get_by_name('kill-word'))
    handle(Keys.Escape, 'f')(get_by_name('forward-word'))
    handle(Keys.Escape, 'l', filter=insert_mode)(get_by_name('downcase-word'))
    handle(Keys.Escape, 'u', filter=insert_mode)(get_by_name('uppercase-word'))
    handle(Keys.Escape, 'y', filter=insert_mode)(get_by_name('yank-pop'))
    handle(Keys.Escape, Keys.ControlH, filter=insert_mode)(get_by_name('backward-kill-word'))
    handle(Keys.Escape, Keys.Backspace, filter=insert_mode)(get_by_name('backward-kill-word'))
    handle(Keys.Escape, '\\', filter=insert_mode)(get_by_name('delete-horizontal-space'))

    handle(Keys.ControlUnderscore, save_before=(lambda e: False), filter=insert_mode)(
        get_by_name('undo'))

    handle(Keys.ControlX, Keys.ControlU, save_before=(lambda e: False), filter=insert_mode)(
        get_by_name('undo'))


    handle(Keys.Escape, '<', filter= ~has_selection)(get_by_name('beginning-of-history'))
    handle(Keys.Escape, '>', filter= ~has_selection)(get_by_name('end-of-history'))

    handle(Keys.Escape, '.', filter=insert_mode)(get_by_name('yank-last-arg'))
    handle(Keys.Escape, '_', filter=insert_mode)(get_by_name('yank-last-arg'))
    handle(Keys.Escape, Keys.ControlY, filter=insert_mode)(get_by_name('yank-nth-arg'))
    handle(Keys.Escape, '#', filter=insert_mode)(get_by_name('insert-comment'))
    handle(Keys.ControlO)(get_by_name('operate-and-get-next'))

    # ControlQ does a quoted insert. Not that for vt100 terminals, you have to
    # disable flow control by running ``stty -ixon``, otherwise Ctrl-Q and
    # Ctrl-S are captured by the terminal.
    handle(Keys.ControlQ, filter= ~has_selection)(get_by_name('quoted-insert'))

    handle(Keys.ControlX, '(')(get_by_name('start-kbd-macro'))
    handle(Keys.ControlX, ')')(get_by_name('end-kbd-macro'))
    handle(Keys.ControlX, 'e')(get_by_name('call-last-kbd-macro'))

    @handle(Keys.ControlN)
    def _(event):
        " Next line. "
        event.current_buffer.auto_down()

    @handle(Keys.ControlP)
    def _(event):
        " Previous line. "
        event.current_buffer.auto_up(count=event.arg)

    def handle_digit(c):
        """
        Handle input of arguments.
        The first number needs to be preceeded by escape.
        """
        @handle(c, filter=HasArg())
        @handle(Keys.Escape, c)
        def _(event):
            event.append_to_arg_count(c)

    for c in '0123456789':
        handle_digit(c)

    @handle(Keys.Escape, '-', filter=~HasArg())
    def _(event):
        """
        """
        if event._arg is None:
            event.append_to_arg_count('-')

    @handle('-', filter=Condition(lambda cli: cli.input_processor.arg == '-'))
    def _(event):
        """
        When '-' is typed again, after exactly '-' has been given as an
        argument, ignore this.
        """
        event.cli.input_processor.arg = '-'

    is_returnable = Condition(
        lambda cli: cli.current_buffer.accept_action.is_returnable)

    # Meta + Newline: always accept input.
    handle(Keys.Escape, Keys.ControlJ, filter=insert_mode & is_returnable)(
        get_by_name('accept-line'))

    def character_search(buff, char, count):
        if count < 0:
            match = buff.document.find_backwards(char, in_current_line=True, count=-count)
        else:
            match = buff.document.find(char, in_current_line=True, count=count)

        if match is not None:
            buff.cursor_position += match

    @handle(Keys.ControlSquareClose, Keys.Any)
    def _(event):
        " When Ctl-] + a character is pressed. go to that character. "
        # Also named 'character-search'
        character_search(event.current_buffer, event.data, event.arg)

    @handle(Keys.Escape, Keys.ControlSquareClose, Keys.Any)
    def _(event):
        " Like Ctl-], but backwards. "
        # Also named 'character-search-backward'
        character_search(event.current_buffer, event.data, -event.arg)

    @handle(Keys.Escape, 'a')
    def _(event):
        " Previous sentence. "
        # TODO:

    @handle(Keys.Escape, 'e')
    def _(event):
        " Move to end of sentence. "
        # TODO:

    @handle(Keys.Escape, 't', filter=insert_mode)
    def _(event):
        """
        Swap the last two words before the cursor.
        """
        # TODO

    @handle(Keys.Escape, '*', filter=insert_mode)
    def _(event):
        """
        `meta-*`: Insert all possible completions of the preceding text.
        """
        buff = event.current_buffer

        # List all completions.
        complete_event = CompleteEvent(text_inserted=False, completion_requested=True)
        completions = list(buff.completer.get_completions(buff.document, complete_event))

        # Insert them.
        text_to_insert = ' '.join(c.text for c in completions)
        buff.insert_text(text_to_insert)

    @handle(Keys.ControlX, Keys.ControlX)
    def _(event):
        """
        Move cursor back and forth between the start and end of the current
        line.
        """
        buffer = event.current_buffer

        if buffer.document.is_cursor_at_the_end_of_line:
            buffer.cursor_position += buffer.document.get_start_of_line_position(after_whitespace=False)
        else:
            buffer.cursor_position += buffer.document.get_end_of_line_position()

    @handle(Keys.ControlSpace)
    def _(event):
        """
        Start of the selection (if the current buffer is not empty).
        """
        # Take the current cursor position as the start of this selection.
        buff = event.current_buffer
        if buff.text:
            buff.start_selection(selection_type=SelectionType.CHARACTERS)

    @handle(Keys.ControlG, filter= ~has_selection)
    def _(event):
        """
        Control + G: Cancel completion menu and validation state.
        """
        event.current_buffer.complete_state = None
        event.current_buffer.validation_error = None

    @handle(Keys.ControlG, filter=has_selection)
    def _(event):
        """
        Cancel selection.
        """
        event.current_buffer.exit_selection()

    @handle(Keys.ControlW, filter=has_selection)
    @handle(Keys.ControlX, 'r', 'k', filter=has_selection)
    def _(event):
        """
        Cut selected text.
        """
        data = event.current_buffer.cut_selection()
        event.cli.clipboard.set_data(data)

    @handle(Keys.Escape, 'w', filter=has_selection)
    def _(event):
        """
        Copy selected text.
        """
        data = event.current_buffer.copy_selection()
        event.cli.clipboard.set_data(data)

    @handle(Keys.Escape, Keys.Left)
    def _(event):
        """
        Cursor to start of previous word.
        """
        buffer = event.current_buffer
        buffer.cursor_position += buffer.document.find_previous_word_beginning(count=event.arg) or 0

    @handle(Keys.Escape, Keys.Right)
    def _(event):
        """
        Cursor to start of next word.
        """
        buffer = event.current_buffer
        buffer.cursor_position += buffer.document.find_next_word_beginning(count=event.arg) or \
            buffer.document.get_end_of_document_position()

    @handle(Keys.Escape, '/', filter=insert_mode)
    def _(event):
        """
        M-/: Complete.
        """
        b = event.current_buffer
        if b.complete_state:
            b.complete_next()
        else:
            event.cli.start_completion(select_first=True)

    @handle(Keys.ControlC, '>', filter=has_selection)
    def _(event):
        """
        Indent selected text.
        """
        buffer = event.current_buffer

        buffer.cursor_position += buffer.document.get_start_of_line_position(after_whitespace=True)

        from_, to = buffer.document.selection_range()
        from_, _ = buffer.document.translate_index_to_position(from_)
        to, _ = buffer.document.translate_index_to_position(to)

        indent(buffer, from_, to + 1, count=event.arg)

    @handle(Keys.ControlC, '<', filter=has_selection)
    def _(event):
        """
        Unindent selected text.
        """
        buffer = event.current_buffer

        from_, to = buffer.document.selection_range()
        from_, _ = buffer.document.translate_index_to_position(from_)
        to, _ = buffer.document.translate_index_to_position(to)

        unindent(buffer, from_, to + 1, count=event.arg)

    return registry
Some e-macs extensions.