Add `delete` binding for clearing auto-suggestion (#13990)

Closes  #13987 assuming that we have a consensus.

IPython/terminal/shortcuts/__init__.py

@@ -1,601 +1,606 b''
 """
 Module to define and register Terminal IPython shortcuts with
 :mod:`prompt_toolkit`
 """
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import os
 import signal
 import sys
 import warnings
 from dataclasses import dataclass
 from typing import Callable, Any, Optional, List
 
 from prompt_toolkit.application.current import get_app
 from prompt_toolkit.key_binding import KeyBindings
 from prompt_toolkit.key_binding.key_processor import KeyPressEvent
 from prompt_toolkit.key_binding.bindings import named_commands as nc
 from prompt_toolkit.key_binding.bindings.completion import (
     display_completions_like_readline,
 )
 from prompt_toolkit.key_binding.vi_state import InputMode, ViState
 from prompt_toolkit.filters import Condition
 
 from IPython.core.getipython import get_ipython
 from IPython.terminal.shortcuts import auto_match as match
 from IPython.terminal.shortcuts import auto_suggest
 from IPython.terminal.shortcuts.filters import filter_from_string
 from IPython.utils.decorators import undoc
 
 from prompt_toolkit.enums import DEFAULT_BUFFER
 
 __all__ = ["create_ipython_shortcuts"]
 
 
 @dataclass
 class BaseBinding:
     command: Callable[[KeyPressEvent], Any]
     keys: List[str]
 
 
 @dataclass
 class RuntimeBinding(BaseBinding):
     filter: Condition
 
 
 @dataclass
 class Binding(BaseBinding):
     # while filter could be created by referencing variables directly (rather
     # than created from strings), by using strings we ensure that users will
     # be able to create filters in configuration (e.g. JSON) files too, which
     # also benefits the documentation by enforcing human-readable filter names.
     condition: Optional[str] = None
 
     def __post_init__(self):
         if self.condition:
             self.filter = filter_from_string(self.condition)
         else:
             self.filter = None
 
 
 def create_identifier(handler: Callable):
     parts = handler.__module__.split(".")
     name = handler.__name__
     package = parts[0]
     if len(parts) > 1:
         final_module = parts[-1]
         return f"{package}:{final_module}.{name}"
     else:
         return f"{package}:{name}"
 
 
 AUTO_MATCH_BINDINGS = [
     *[
         Binding(
             cmd, [key], "focused_insert & auto_match & followed_by_closing_paren_or_end"
         )
         for key, cmd in match.auto_match_parens.items()
     ],
     *[
         # raw string
         Binding(cmd, [key], "focused_insert & auto_match & preceded_by_raw_str_prefix")
         for key, cmd in match.auto_match_parens_raw_string.items()
     ],
     Binding(
         match.double_quote,
         ['"'],
         "focused_insert"
         " & auto_match"
         " & not_inside_unclosed_string"
         " & preceded_by_paired_double_quotes"
         " & followed_by_closing_paren_or_end",
     ),
     Binding(
         match.single_quote,
         ["'"],
         "focused_insert"
         " & auto_match"
         " & not_inside_unclosed_string"
         " & preceded_by_paired_single_quotes"
         " & followed_by_closing_paren_or_end",
     ),
     Binding(
         match.docstring_double_quotes,
         ['"'],
         "focused_insert"
         " & auto_match"
         " & not_inside_unclosed_string"
         " & preceded_by_two_double_quotes",
     ),
     Binding(
         match.docstring_single_quotes,
         ["'"],
         "focused_insert"
         " & auto_match"
         " & not_inside_unclosed_string"
         " & preceded_by_two_single_quotes",
     ),
     Binding(
         match.skip_over,
         [")"],
         "focused_insert & auto_match & followed_by_closing_round_paren",
     ),
     Binding(
         match.skip_over,
         ["]"],
         "focused_insert & auto_match & followed_by_closing_bracket",
     ),
     Binding(
         match.skip_over,
         ["}"],
         "focused_insert & auto_match & followed_by_closing_brace",
     ),
     Binding(
         match.skip_over, ['"'], "focused_insert & auto_match & followed_by_double_quote"
     ),
     Binding(
         match.skip_over, ["'"], "focused_insert & auto_match & followed_by_single_quote"
     ),
     Binding(
         match.delete_pair,
         ["backspace"],
         "focused_insert"
         " & preceded_by_opening_round_paren"
         " & auto_match"
         " & followed_by_closing_round_paren",
     ),
     Binding(
         match.delete_pair,
         ["backspace"],
         "focused_insert"
         " & preceded_by_opening_bracket"
         " & auto_match"
         " & followed_by_closing_bracket",
     ),
     Binding(
         match.delete_pair,
         ["backspace"],
         "focused_insert"
         " & preceded_by_opening_brace"
         " & auto_match"
         " & followed_by_closing_brace",
     ),
     Binding(
         match.delete_pair,
         ["backspace"],
         "focused_insert"
         " & preceded_by_double_quote"
         " & auto_match"
         " & followed_by_double_quote",
     ),
     Binding(
         match.delete_pair,
         ["backspace"],
         "focused_insert"
         " & preceded_by_single_quote"
         " & auto_match"
         " & followed_by_single_quote",
     ),
 ]
 
 AUTO_SUGGEST_BINDINGS = [
     Binding(
         auto_suggest.accept_in_vi_insert_mode,
         ["end"],
         "default_buffer_focused & (ebivim | ~vi_insert_mode)",
     ),
     Binding(
         auto_suggest.accept_in_vi_insert_mode,
         ["c-e"],
         "vi_insert_mode & default_buffer_focused & ebivim",
     ),
     Binding(auto_suggest.accept, ["c-f"], "vi_insert_mode & default_buffer_focused"),
     Binding(
         auto_suggest.accept_word,
         ["escape", "f"],
         "vi_insert_mode & default_buffer_focused & ebivim",
     ),
     Binding(
         auto_suggest.accept_token,
         ["c-right"],
         "has_suggestion & default_buffer_focused",
     ),
     Binding(
         auto_suggest.discard,
         ["escape"],
         "has_suggestion & default_buffer_focused & emacs_insert_mode",
     ),
     Binding(
+        auto_suggest.discard,
+        ["delete"],
+        "has_suggestion & default_buffer_focused & emacs_insert_mode",
+    ),
+    Binding(
         auto_suggest.swap_autosuggestion_up,
         ["up"],
         "navigable_suggestions"
         " & ~has_line_above"
         " & has_suggestion"
         " & default_buffer_focused",
     ),
     Binding(
         auto_suggest.swap_autosuggestion_down,
         ["down"],
         "navigable_suggestions"
         " & ~has_line_below"
         " & has_suggestion"
         " & default_buffer_focused",
     ),
     Binding(
         auto_suggest.up_and_update_hint,
         ["up"],
         "has_line_above & navigable_suggestions & default_buffer_focused",
     ),
     Binding(
         auto_suggest.down_and_update_hint,
         ["down"],
         "has_line_below & navigable_suggestions & default_buffer_focused",
     ),
     Binding(
         auto_suggest.accept_character,
         ["escape", "right"],
         "has_suggestion & default_buffer_focused",
     ),
     Binding(
         auto_suggest.accept_and_move_cursor_left,
         ["c-left"],
         "has_suggestion & default_buffer_focused",
     ),
     Binding(
         auto_suggest.accept_and_keep_cursor,
         ["c-down"],
         "has_suggestion & default_buffer_focused",
     ),
     Binding(
         auto_suggest.backspace_and_resume_hint,
         ["backspace"],
         "has_suggestion & default_buffer_focused",
     ),
 ]
 
 
 SIMPLE_CONTROL_BINDINGS = [
     Binding(cmd, [key], "vi_insert_mode & default_buffer_focused & ebivim")
     for key, cmd in {
         "c-a": nc.beginning_of_line,
         "c-b": nc.backward_char,
         "c-k": nc.kill_line,
         "c-w": nc.backward_kill_word,
         "c-y": nc.yank,
         "c-_": nc.undo,
     }.items()
 ]
 
 
 ALT_AND_COMOBO_CONTROL_BINDINGS = [
     Binding(cmd, list(keys), "vi_insert_mode & default_buffer_focused & ebivim")
     for keys, cmd in {
         # Control Combos
         ("c-x", "c-e"): nc.edit_and_execute,
         ("c-x", "e"): nc.edit_and_execute,
         # Alt
         ("escape", "b"): nc.backward_word,
         ("escape", "c"): nc.capitalize_word,
         ("escape", "d"): nc.kill_word,
         ("escape", "h"): nc.backward_kill_word,
         ("escape", "l"): nc.downcase_word,
         ("escape", "u"): nc.uppercase_word,
         ("escape", "y"): nc.yank_pop,
         ("escape", "."): nc.yank_last_arg,
     }.items()
 ]
 
 
 def add_binding(bindings: KeyBindings, binding: Binding):
     bindings.add(
         *binding.keys,
         **({"filter": binding.filter} if binding.filter is not None else {}),
     )(binding.command)
 
 
 def create_ipython_shortcuts(shell, skip=None) -> KeyBindings:
     """Set up the prompt_toolkit keyboard shortcuts for IPython.
 
     Parameters
     ----------
     shell: InteractiveShell
         The current IPython shell Instance
     skip: List[Binding]
         Bindings to skip.
 
     Returns
     -------
     KeyBindings
         the keybinding instance for prompt toolkit.
 
     """
     kb = KeyBindings()
     skip = skip or []
     for binding in KEY_BINDINGS:
         skip_this_one = False
         for to_skip in skip:
             if (
                 to_skip.command == binding.command
                 and to_skip.filter == binding.filter
                 and to_skip.keys == binding.keys
             ):
                 skip_this_one = True
                 break
         if skip_this_one:
             continue
         add_binding(kb, binding)
 
     def get_input_mode(self):
         app = get_app()
         app.ttimeoutlen = shell.ttimeoutlen
         app.timeoutlen = shell.timeoutlen
 
         return self._input_mode
 
     def set_input_mode(self, mode):
         shape = {InputMode.NAVIGATION: 2, InputMode.REPLACE: 4}.get(mode, 6)
         cursor = "\x1b[{} q".format(shape)
 
         sys.stdout.write(cursor)
         sys.stdout.flush()
 
         self._input_mode = mode
 
     if shell.editing_mode == "vi" and shell.modal_cursor:
         ViState._input_mode = InputMode.INSERT  # type: ignore
         ViState.input_mode = property(get_input_mode, set_input_mode)  # type: ignore
 
     return kb
 
 
 def reformat_and_execute(event):
     """Reformat code and execute it"""
     shell = get_ipython()
     reformat_text_before_cursor(
         event.current_buffer, event.current_buffer.document, shell
     )
     event.current_buffer.validate_and_handle()
 
 
 def reformat_text_before_cursor(buffer, document, shell):
     text = buffer.delete_before_cursor(len(document.text[: document.cursor_position]))
     try:
         formatted_text = shell.reformat_handler(text)
         buffer.insert_text(formatted_text)
     except Exception as e:
         buffer.insert_text(text)
 
 
 def handle_return_or_newline_or_execute(event):
     shell = get_ipython()
     if getattr(shell, "handle_return", None):
         return shell.handle_return(shell)(event)
     else:
         return newline_or_execute_outer(shell)(event)
 
 
 def newline_or_execute_outer(shell):
     def newline_or_execute(event):
         """When the user presses return, insert a newline or execute the code."""
         b = event.current_buffer
         d = b.document
 
         if b.complete_state:
             cc = b.complete_state.current_completion
             if cc:
                 b.apply_completion(cc)
             else:
                 b.cancel_completion()
             return
 
         # If there's only one line, treat it as if the cursor is at the end.
         # See https://github.com/ipython/ipython/issues/10425
         if d.line_count == 1:
             check_text = d.text
         else:
             check_text = d.text[: d.cursor_position]
         status, indent = shell.check_complete(check_text)
 
         # if all we have after the cursor is whitespace: reformat current text
         # before cursor
         after_cursor = d.text[d.cursor_position :]
         reformatted = False
         if not after_cursor.strip():
             reformat_text_before_cursor(b, d, shell)
             reformatted = True
         if not (
             d.on_last_line
             or d.cursor_position_row >= d.line_count - d.empty_line_count_at_the_end()
         ):
             if shell.autoindent:
                 b.insert_text("\n" + indent)
             else:
                 b.insert_text("\n")
             return
 
         if (status != "incomplete") and b.accept_handler:
             if not reformatted:
                 reformat_text_before_cursor(b, d, shell)
             b.validate_and_handle()
         else:
             if shell.autoindent:
                 b.insert_text("\n" + indent)
             else:
                 b.insert_text("\n")
 
     return newline_or_execute
 
 
 def previous_history_or_previous_completion(event):
     """
     Control-P in vi edit mode on readline is history next, unlike default prompt toolkit.
 
     If completer is open this still select previous completion.
     """
     event.current_buffer.auto_up()
 
 
 def next_history_or_next_completion(event):
     """
     Control-N in vi edit mode on readline is history previous, unlike default prompt toolkit.
 
     If completer is open this still select next completion.
     """
     event.current_buffer.auto_down()
 
 
 def dismiss_completion(event):
     """Dismiss completion"""
     b = event.current_buffer
     if b.complete_state:
         b.cancel_completion()
 
 
 def reset_buffer(event):
     """Reset buffer"""
     b = event.current_buffer
     if b.complete_state:
         b.cancel_completion()
     else:
         b.reset()
 
 
 def reset_search_buffer(event):
     """Reset search buffer"""
     if event.current_buffer.document.text:
         event.current_buffer.reset()
     else:
         event.app.layout.focus(DEFAULT_BUFFER)
 
 
 def suspend_to_bg(event):
     """Suspend to background"""
     event.app.suspend_to_background()
 
 
 def quit(event):
     """
     Quit application with ``SIGQUIT`` if supported or ``sys.exit`` otherwise.
 
     On platforms that support SIGQUIT, send SIGQUIT to the current process.
     On other platforms, just exit the process with a message.
     """
     sigquit = getattr(signal, "SIGQUIT", None)
     if sigquit is not None:
         os.kill(0, signal.SIGQUIT)
     else:
         sys.exit("Quit")
 
 
 def indent_buffer(event):
     """Indent buffer"""
     event.current_buffer.insert_text(" " * 4)
 
 
 def newline_autoindent(event):
     """Insert a newline after the cursor indented appropriately.
 
     Fancier version of former ``newline_with_copy_margin`` which should
     compute the correct indentation of the inserted line. That is to say, indent
     by 4 extra space after a function definition, class definition, context
     manager... And dedent by 4 space after ``pass``, ``return``, ``raise ...``.
     """
     shell = get_ipython()
     inputsplitter = shell.input_transformer_manager
     b = event.current_buffer
     d = b.document
 
     if b.complete_state:
         b.cancel_completion()
     text = d.text[: d.cursor_position] + "\n"
     _, indent = inputsplitter.check_complete(text)
     b.insert_text("\n" + (" " * (indent or 0)), move_cursor=False)
 
 
 def open_input_in_editor(event):
     """Open code from input in external editor"""
     event.app.current_buffer.open_in_editor()
 
 
 if sys.platform == "win32":
     from IPython.core.error import TryNext
     from IPython.lib.clipboard import (
         ClipboardEmpty,
         tkinter_clipboard_get,
         win32_clipboard_get,
     )
 
     @undoc
     def win_paste(event):
         try:
             text = win32_clipboard_get()
         except TryNext:
             try:
                 text = tkinter_clipboard_get()
             except (TryNext, ClipboardEmpty):
                 return
         except ClipboardEmpty:
             return
         event.current_buffer.insert_text(text.replace("\t", " " * 4))
 
 else:
 
     @undoc
     def win_paste(event):
         """Stub used on other platforms"""
         pass
 
 
 KEY_BINDINGS = [
     Binding(
         handle_return_or_newline_or_execute,
         ["enter"],
         "default_buffer_focused & ~has_selection & insert_mode",
     ),
     Binding(
         reformat_and_execute,
         ["escape", "enter"],
         "default_buffer_focused & ~has_selection & insert_mode & ebivim",
     ),
     Binding(quit, ["c-\\"]),
     Binding(
         previous_history_or_previous_completion,
         ["c-p"],
         "vi_insert_mode & default_buffer_focused",
     ),
     Binding(
         next_history_or_next_completion,
         ["c-n"],
         "vi_insert_mode & default_buffer_focused",
     ),
     Binding(dismiss_completion, ["c-g"], "default_buffer_focused & has_completions"),
     Binding(reset_buffer, ["c-c"], "default_buffer_focused"),
     Binding(reset_search_buffer, ["c-c"], "search_buffer_focused"),
     Binding(suspend_to_bg, ["c-z"], "supports_suspend"),
     Binding(
         indent_buffer,
         ["tab"],  # Ctrl+I == Tab
         "default_buffer_focused"
         " & ~has_selection"
         " & insert_mode"
         " & cursor_in_leading_ws",
     ),
     Binding(newline_autoindent, ["c-o"], "default_buffer_focused & emacs_insert_mode"),
     Binding(open_input_in_editor, ["f2"], "default_buffer_focused"),
     *AUTO_MATCH_BINDINGS,
     *AUTO_SUGGEST_BINDINGS,
     Binding(
         display_completions_like_readline,
         ["c-i"],
         "readline_like_completions"
         " & default_buffer_focused"
         " & ~has_selection"
         " & insert_mode"
         " & ~cursor_in_leading_ws",
     ),
     Binding(win_paste, ["c-v"], "default_buffer_focused & ~vi_mode & is_windows_os"),
     *SIMPLE_CONTROL_BINDINGS,
     *ALT_AND_COMOBO_CONTROL_BINDINGS,
 ]