178 lines
5.7 KiB
Python
178 lines
5.7 KiB
Python
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"""
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`Fish-style <http://fishshell.com/>`_ like auto-suggestion.
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While a user types input in a certain buffer, suggestions are generated
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(asynchronously.) Usually, they are displayed after the input. When the cursor
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presses the right arrow and the cursor is at the end of the input, the
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suggestion will be inserted.
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If you want the auto suggestions to be asynchronous (in a background thread),
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because they take too much time, and could potentially block the event loop,
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then wrap the :class:`.AutoSuggest` instance into a
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:class:`.ThreadedAutoSuggest`.
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"""
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from __future__ import annotations
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from abc import ABCMeta, abstractmethod
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from typing import TYPE_CHECKING, Callable
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from prompt_toolkit.eventloop import run_in_executor_with_context
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from .document import Document
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from .filters import Filter, to_filter
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if TYPE_CHECKING:
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from .buffer import Buffer
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__all__ = [
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"Suggestion",
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"AutoSuggest",
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"ThreadedAutoSuggest",
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"DummyAutoSuggest",
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"AutoSuggestFromHistory",
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"ConditionalAutoSuggest",
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"DynamicAutoSuggest",
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]
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class Suggestion:
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"""
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Suggestion returned by an auto-suggest algorithm.
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:param text: The suggestion text.
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"""
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def __init__(self, text: str) -> None:
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self.text = text
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def __repr__(self) -> str:
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return f"Suggestion({self.text})"
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class AutoSuggest(metaclass=ABCMeta):
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"""
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Base class for auto suggestion implementations.
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"""
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@abstractmethod
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def get_suggestion(self, buffer: Buffer, document: Document) -> Suggestion | None:
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"""
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Return `None` or a :class:`.Suggestion` instance.
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We receive both :class:`~prompt_toolkit.buffer.Buffer` and
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:class:`~prompt_toolkit.document.Document`. The reason is that auto
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suggestions are retrieved asynchronously. (Like completions.) The
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buffer text could be changed in the meantime, but ``document`` contains
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the buffer document like it was at the start of the auto suggestion
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call. So, from here, don't access ``buffer.text``, but use
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``document.text`` instead.
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:param buffer: The :class:`~prompt_toolkit.buffer.Buffer` instance.
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:param document: The :class:`~prompt_toolkit.document.Document` instance.
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"""
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async def get_suggestion_async(
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self, buff: Buffer, document: Document
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) -> Suggestion | None:
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"""
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Return a :class:`.Future` which is set when the suggestions are ready.
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This function can be overloaded in order to provide an asynchronous
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implementation.
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"""
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return self.get_suggestion(buff, document)
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class ThreadedAutoSuggest(AutoSuggest):
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"""
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Wrapper that runs auto suggestions in a thread.
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(Use this to prevent the user interface from becoming unresponsive if the
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generation of suggestions takes too much time.)
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"""
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def __init__(self, auto_suggest: AutoSuggest) -> None:
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self.auto_suggest = auto_suggest
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def get_suggestion(self, buff: Buffer, document: Document) -> Suggestion | None:
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return self.auto_suggest.get_suggestion(buff, document)
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async def get_suggestion_async(
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self, buff: Buffer, document: Document
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) -> Suggestion | None:
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"""
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Run the `get_suggestion` function in a thread.
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"""
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def run_get_suggestion_thread() -> Suggestion | None:
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return self.get_suggestion(buff, document)
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return await run_in_executor_with_context(run_get_suggestion_thread)
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class DummyAutoSuggest(AutoSuggest):
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"""
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AutoSuggest class that doesn't return any suggestion.
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"""
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def get_suggestion(self, buffer: Buffer, document: Document) -> Suggestion | None:
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return None # No suggestion
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class AutoSuggestFromHistory(AutoSuggest):
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"""
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Give suggestions based on the lines in the history.
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"""
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def get_suggestion(self, buffer: Buffer, document: Document) -> Suggestion | None:
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history = buffer.history
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# Consider only the last line for the suggestion.
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text = document.text.rsplit("\n", 1)[-1]
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# Only create a suggestion when this is not an empty line.
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if text.strip():
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# Find first matching line in history.
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for string in reversed(list(history.get_strings())):
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for line in reversed(string.splitlines()):
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if line.startswith(text):
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return Suggestion(line[len(text) :])
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return None
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class ConditionalAutoSuggest(AutoSuggest):
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"""
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Auto suggest that can be turned on and of according to a certain condition.
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"""
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def __init__(self, auto_suggest: AutoSuggest, filter: bool | Filter) -> None:
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self.auto_suggest = auto_suggest
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self.filter = to_filter(filter)
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def get_suggestion(self, buffer: Buffer, document: Document) -> Suggestion | None:
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if self.filter():
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return self.auto_suggest.get_suggestion(buffer, document)
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return None
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class DynamicAutoSuggest(AutoSuggest):
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"""
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Validator class that can dynamically returns any Validator.
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:param get_validator: Callable that returns a :class:`.Validator` instance.
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"""
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def __init__(self, get_auto_suggest: Callable[[], AutoSuggest | None]) -> None:
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self.get_auto_suggest = get_auto_suggest
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def get_suggestion(self, buff: Buffer, document: Document) -> Suggestion | None:
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auto_suggest = self.get_auto_suggest() or DummyAutoSuggest()
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return auto_suggest.get_suggestion(buff, document)
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async def get_suggestion_async(
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self, buff: Buffer, document: Document
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) -> Suggestion | None:
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auto_suggest = self.get_auto_suggest() or DummyAutoSuggest()
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return await auto_suggest.get_suggestion_async(buff, document)
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