Shared via mypy Playground

main.py

"""
Functions for *walking* the DOM.

!!! note

    For most purposes you would be better off using [query][textual.dom.DOMNode.query], which uses these functions internally.
"""

from __future__ import annotations

from collections import deque
from typing import TYPE_CHECKING, Iterable, Iterator, TypeVar, overload

class DOMNode:
    pass

WalkType = TypeVar("WalkType", bound=DOMNode)


if TYPE_CHECKING:

    @overload
    def walk_depth_first(
        root: DOMNode,
        *,
        with_root: bool = True,
    ) -> Iterable[DOMNode]: ...

    @overload
    def walk_depth_first(
        root: WalkType,
        filter_type: type[WalkType],
        *,
        with_root: bool = True,
    ) -> Iterable[WalkType]: ...


def walk_depth_first(
    root: DOMNode,
    filter_type: type[WalkType] | None = None,
    *,
    with_root: bool = True,
) -> Iterable[DOMNode] | Iterable[WalkType]:
    return []


if TYPE_CHECKING:

    @overload
    def walk_breadth_first(
        root: DOMNode,
        *,
        with_root: bool = True,
    ) -> Iterable[DOMNode]: ...

    @overload
    def walk_breadth_first(
        root: WalkType,
        filter_type: type[WalkType],
        *,
        with_root: bool = True,
    ) -> Iterable[WalkType]: ...


def walk_breadth_first(
    root: DOMNode,
    filter_type: type[WalkType] | None = None,
    *,
    with_root: bool = True,
) -> Iterable[DOMNode] | Iterable[WalkType]:
    return []