import re import tokenize from io import StringIO from typing import Callable, List, Optional, Union, Generator, Tuple from prompt_toolkit.buffer import Buffer from prompt_toolkit.key_binding import KeyPressEvent from prompt_toolkit.key_binding.bindings import named_commands as nc from prompt_toolkit.auto_suggest import AutoSuggestFromHistory, Suggestion from prompt_toolkit.document import Document from prompt_toolkit.history import History from prompt_toolkit.shortcuts import PromptSession from prompt_toolkit.layout.processors import ( Processor, Transformation, TransformationInput, ) from IPython.core.getipython import get_ipython from IPython.utils.tokenutil import generate_tokens def _get_query(document: Document): return document.lines[document.cursor_position_row] class AppendAutoSuggestionInAnyLine(Processor): """ Append the auto suggestion to lines other than the last (appending to the last line is natively supported by the prompt toolkit). """ def __init__(self, style: str = "class:auto-suggestion") -> None: self.style = style def apply_transformation(self, ti: TransformationInput) -> Transformation: is_last_line = ti.lineno == ti.document.line_count - 1 is_active_line = ti.lineno == ti.document.cursor_position_row if not is_last_line and is_active_line: buffer = ti.buffer_control.buffer if buffer.suggestion and ti.document.is_cursor_at_the_end_of_line: suggestion = buffer.suggestion.text else: suggestion = "" return Transformation(fragments=ti.fragments + [(self.style, suggestion)]) else: return Transformation(fragments=ti.fragments) class NavigableAutoSuggestFromHistory(AutoSuggestFromHistory): """ A subclass of AutoSuggestFromHistory that allow navigation to next/previous suggestion from history. To do so it remembers the current position, but it state need to carefully be cleared on the right events. """ def __init__( self, ): self.skip_lines = 0 self._connected_apps = [] def reset_history_position(self, _: Buffer): self.skip_lines = 0 def disconnect(self): for pt_app in self._connected_apps: text_insert_event = pt_app.default_buffer.on_text_insert text_insert_event.remove_handler(self.reset_history_position) def connect(self, pt_app: PromptSession): self._connected_apps.append(pt_app) # note: `on_text_changed` could be used for a bit different behaviour # on character deletion (i.e. reseting history position on backspace) pt_app.default_buffer.on_text_insert.add_handler(self.reset_history_position) pt_app.default_buffer.on_cursor_position_changed.add_handler(self._dismiss) def get_suggestion( self, buffer: Buffer, document: Document ) -> Optional[Suggestion]: text = _get_query(document) if text.strip(): for suggestion, _ in self._find_next_match( text, self.skip_lines, buffer.history ): return Suggestion(suggestion) return None def _dismiss(self, buffer, *args, **kwargs): buffer.suggestion = None def _find_match( self, text: str, skip_lines: float, history: History, previous: bool ) -> Generator[Tuple[str, float], None, None]: """ text : str Text content to find a match for, the user cursor is most of the time at the end of this text. skip_lines : float number of items to skip in the search, this is used to indicate how far in the list the user has navigated by pressing up or down. The float type is used as the base value is +inf history : History prompt_toolkit History instance to fetch previous entries from. previous : bool Direction of the search, whether we are looking previous match (True), or next match (False). Yields ------ Tuple with: str: current suggestion. float: will actually yield only ints, which is passed back via skip_lines, which may be a +inf (float) """ line_number = -1 for string in reversed(list(history.get_strings())): for line in reversed(string.splitlines()): line_number += 1 if not previous and line_number < skip_lines: continue # do not return empty suggestions as these # close the auto-suggestion overlay (and are useless) if line.startswith(text) and len(line) > len(text): yield line[len(text) :], line_number if previous and line_number >= skip_lines: return def _find_next_match( self, text: str, skip_lines: float, history: History ) -> Generator[Tuple[str, float], None, None]: return self._find_match(text, skip_lines, history, previous=False) def _find_previous_match(self, text: str, skip_lines: float, history: History): return reversed( list(self._find_match(text, skip_lines, history, previous=True)) ) def up(self, query: str, other_than: str, history: History) -> None: for suggestion, line_number in self._find_next_match( query, self.skip_lines, history ): # if user has history ['very.a', 'very', 'very.b'] and typed 'very' # we want to switch from 'very.b' to 'very.a' because a) if the # suggestion equals current text, prompt-toolkit aborts suggesting # b) user likely would not be interested in 'very' anyways (they # already typed it). if query + suggestion != other_than: self.skip_lines = line_number break else: # no matches found, cycle back to beginning self.skip_lines = 0 def down(self, query: str, other_than: str, history: History) -> None: for suggestion, line_number in self._find_previous_match( query, self.skip_lines, history ): if query + suggestion != other_than: self.skip_lines = line_number break else: # no matches found, cycle to end for suggestion, line_number in self._find_previous_match( query, float("Inf"), history ): if query + suggestion != other_than: self.skip_lines = line_number break # Needed for to accept autosuggestions in vi insert mode def accept_in_vi_insert_mode(event: KeyPressEvent): """Apply autosuggestion if at end of line.""" buffer = event.current_buffer d = buffer.document after_cursor = d.text[d.cursor_position :] lines = after_cursor.split("\n") end_of_current_line = lines[0].strip() suggestion = buffer.suggestion if (suggestion is not None) and (suggestion.text) and (end_of_current_line == ""): buffer.insert_text(suggestion.text) else: nc.end_of_line(event) def accept(event: KeyPressEvent): """Accept autosuggestion""" buffer = event.current_buffer suggestion = buffer.suggestion if suggestion: buffer.insert_text(suggestion.text) else: nc.forward_char(event) def discard(event: KeyPressEvent): """Discard autosuggestion""" buffer = event.current_buffer buffer.suggestion = None def accept_word(event: KeyPressEvent): """Fill partial autosuggestion by word""" buffer = event.current_buffer suggestion = buffer.suggestion if suggestion: t = re.split(r"(\S+\s+)", suggestion.text) buffer.insert_text(next((x for x in t if x), "")) else: nc.forward_word(event) def accept_character(event: KeyPressEvent): """Fill partial autosuggestion by character""" b = event.current_buffer suggestion = b.suggestion if suggestion and suggestion.text: b.insert_text(suggestion.text[0]) def accept_and_keep_cursor(event: KeyPressEvent): """Accept autosuggestion and keep cursor in place""" buffer = event.current_buffer old_position = buffer.cursor_position suggestion = buffer.suggestion if suggestion: buffer.insert_text(suggestion.text) buffer.cursor_position = old_position def accept_and_move_cursor_left(event: KeyPressEvent): """Accept autosuggestion and move cursor left in place""" accept_and_keep_cursor(event) nc.backward_char(event) def _update_hint(buffer: Buffer): if buffer.auto_suggest: suggestion = buffer.auto_suggest.get_suggestion(buffer, buffer.document) buffer.suggestion = suggestion def backspace_and_resume_hint(event: KeyPressEvent): """Resume autosuggestions after deleting last character""" current_buffer = event.current_buffer def resume_hinting(buffer: Buffer): _update_hint(buffer) current_buffer.on_text_changed.remove_handler(resume_hinting) current_buffer.on_text_changed.add_handler(resume_hinting) nc.backward_delete_char(event) def up_and_update_hint(event: KeyPressEvent): """Go up and update hint""" current_buffer = event.current_buffer current_buffer.auto_up(count=event.arg) _update_hint(current_buffer) def down_and_update_hint(event: KeyPressEvent): """Go down and update hint""" current_buffer = event.current_buffer current_buffer.auto_down(count=event.arg) _update_hint(current_buffer) def accept_token(event: KeyPressEvent): """Fill partial autosuggestion by token""" b = event.current_buffer suggestion = b.suggestion if suggestion: prefix = _get_query(b.document) text = prefix + suggestion.text tokens: List[Optional[str]] = [None, None, None] substrings = [""] i = 0 for token in generate_tokens(StringIO(text).readline): if token.type == tokenize.NEWLINE: index = len(text) else: index = text.index(token[1], len(substrings[-1])) substrings.append(text[:index]) tokenized_so_far = substrings[-1] if tokenized_so_far.startswith(prefix): if i == 0 and len(tokenized_so_far) > len(prefix): tokens[0] = tokenized_so_far[len(prefix) :] substrings.append(tokenized_so_far) i += 1 tokens[i] = token[1] if i == 2: break i += 1 if tokens[0]: to_insert: str insert_text = substrings[-2] if tokens[1] and len(tokens[1]) == 1: insert_text = substrings[-1] to_insert = insert_text[len(prefix) :] b.insert_text(to_insert) return nc.forward_word(event) Provider = Union[AutoSuggestFromHistory, NavigableAutoSuggestFromHistory, None] def _swap_autosuggestion( buffer: Buffer, provider: NavigableAutoSuggestFromHistory, direction_method: Callable, ): """ We skip most recent history entry (in either direction) if it equals the current autosuggestion because if user cycles when auto-suggestion is shown they most likely want something else than what was suggested (otherwise they would have accepted the suggestion). """ suggestion = buffer.suggestion if not suggestion: return query = _get_query(buffer.document) current = query + suggestion.text direction_method(query=query, other_than=current, history=buffer.history) new_suggestion = provider.get_suggestion(buffer, buffer.document) buffer.suggestion = new_suggestion def swap_autosuggestion_up(event: KeyPressEvent): """Get next autosuggestion from history.""" shell = get_ipython() provider = shell.auto_suggest if not isinstance(provider, NavigableAutoSuggestFromHistory): return return _swap_autosuggestion( buffer=event.current_buffer, provider=provider, direction_method=provider.up ) def swap_autosuggestion_down(event: KeyPressEvent): """Get previous autosuggestion from history.""" shell = get_ipython() provider = shell.auto_suggest if not isinstance(provider, NavigableAutoSuggestFromHistory): return return _swap_autosuggestion( buffer=event.current_buffer, provider=provider, direction_method=provider.down, )