Adding upstream version 3.0.36.upstream/3.0.36upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 187 insertions, 0 deletions

diff --git a/src/prompt_toolkit/auto_suggest.py b/src/prompt_toolkit/auto_suggest.py
new file mode 100644
index 0000000..7099b8e
--- /dev/null
+++ b/src/prompt_toolkit/auto_suggest.py
@@ -0,0 +1,187 @@
+"""
+`Fish-style <http://fishshell.com/>`_  like auto-suggestion.
+
+While a user types input in a certain buffer, suggestions are generated
+(asynchronously.) Usually, they are displayed after the input. When the cursor
+presses the right arrow and the cursor is at the end of the input, the
+suggestion will be inserted.
+
+If you want the auto suggestions to be asynchronous (in a background thread),
+because they take too much time, and could potentially block the event loop,
+then wrap the :class:`.AutoSuggest` instance into a
+:class:`.ThreadedAutoSuggest`.
+"""
+from abc import ABCMeta, abstractmethod
+from typing import TYPE_CHECKING, Callable, Optional, Union
+
+from prompt_toolkit.eventloop import run_in_executor_with_context
+
+from .document import Document
+from .filters import Filter, to_filter
+
+if TYPE_CHECKING:
+    from .buffer import Buffer
+
+__all__ = [
+    "Suggestion",
+    "AutoSuggest",
+    "ThreadedAutoSuggest",
+    "DummyAutoSuggest",
+    "AutoSuggestFromHistory",
+    "ConditionalAutoSuggest",
+    "DynamicAutoSuggest",
+]
+
+
+class Suggestion:
+    """
+    Suggestion returned by an auto-suggest algorithm.
+
+    :param text: The suggestion text.
+    """
+
+    def __init__(self, text: str) -> None:
+        self.text = text
+
+    def __repr__(self) -> str:
+        return "Suggestion(%s)" % self.text
+
+
+class AutoSuggest(metaclass=ABCMeta):
+    """
+    Base class for auto suggestion implementations.
+    """
+
+    @abstractmethod
+    def get_suggestion(
+        self, buffer: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        """
+        Return `None` or a :class:`.Suggestion` instance.
+
+        We receive both :class:`~prompt_toolkit.buffer.Buffer` and
+        :class:`~prompt_toolkit.document.Document`. The reason is that auto
+        suggestions are retrieved asynchronously. (Like completions.) The
+        buffer text could be changed in the meantime, but ``document`` contains
+        the buffer document like it was at the start of the auto suggestion
+        call. So, from here, don't access ``buffer.text``, but use
+        ``document.text`` instead.
+
+        :param buffer: The :class:`~prompt_toolkit.buffer.Buffer` instance.
+        :param document: The :class:`~prompt_toolkit.document.Document` instance.
+        """
+
+    async def get_suggestion_async(
+        self, buff: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        """
+        Return a :class:`.Future` which is set when the suggestions are ready.
+        This function can be overloaded in order to provide an asynchronous
+        implementation.
+        """
+        return self.get_suggestion(buff, document)
+
+
+class ThreadedAutoSuggest(AutoSuggest):
+    """
+    Wrapper that runs auto suggestions in a thread.
+    (Use this to prevent the user interface from becoming unresponsive if the
+    generation of suggestions takes too much time.)
+    """
+
+    def __init__(self, auto_suggest: AutoSuggest) -> None:
+        self.auto_suggest = auto_suggest
+
+    def get_suggestion(
+        self, buff: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        return self.auto_suggest.get_suggestion(buff, document)
+
+    async def get_suggestion_async(
+        self, buff: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        """
+        Run the `get_suggestion` function in a thread.
+        """
+
+        def run_get_suggestion_thread() -> Optional[Suggestion]:
+            return self.get_suggestion(buff, document)
+
+        return await run_in_executor_with_context(run_get_suggestion_thread)
+
+
+class DummyAutoSuggest(AutoSuggest):
+    """
+    AutoSuggest class that doesn't return any suggestion.
+    """
+
+    def get_suggestion(
+        self, buffer: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        return None  # No suggestion
+
+
+class AutoSuggestFromHistory(AutoSuggest):
+    """
+    Give suggestions based on the lines in the history.
+    """
+
+    def get_suggestion(
+        self, buffer: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        history = buffer.history
+
+        # Consider only the last line for the suggestion.
+        text = document.text.rsplit("\n", 1)[-1]
+
+        # Only create a suggestion when this is not an empty line.
+        if text.strip():
+            # Find first matching line in history.
+            for string in reversed(list(history.get_strings())):
+                for line in reversed(string.splitlines()):
+                    if line.startswith(text):
+                        return Suggestion(line[len(text) :])
+
+        return None
+
+
+class ConditionalAutoSuggest(AutoSuggest):
+    """
+    Auto suggest that can be turned on and of according to a certain condition.
+    """
+
+    def __init__(self, auto_suggest: AutoSuggest, filter: Union[bool, Filter]) -> None:
+
+        self.auto_suggest = auto_suggest
+        self.filter = to_filter(filter)
+
+    def get_suggestion(
+        self, buffer: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        if self.filter():
+            return self.auto_suggest.get_suggestion(buffer, document)
+
+        return None
+
+
+class DynamicAutoSuggest(AutoSuggest):
+    """
+    Validator class that can dynamically returns any Validator.
+
+    :param get_validator: Callable that returns a :class:`.Validator` instance.
+    """
+
+    def __init__(self, get_auto_suggest: Callable[[], Optional[AutoSuggest]]) -> None:
+        self.get_auto_suggest = get_auto_suggest
+
+    def get_suggestion(
+        self, buff: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        auto_suggest = self.get_auto_suggest() or DummyAutoSuggest()
+        return auto_suggest.get_suggestion(buff, document)
+
+    async def get_suggestion_async(
+        self, buff: "Buffer", document: Document
+    ) -> Optional[Suggestion]:
+        auto_suggest = self.get_auto_suggest() or DummyAutoSuggest()
+        return await auto_suggest.get_suggestion_async(buff, document)