Skip to content

Breadth First

Module: terminaltexteffects.utils.spanningtree.algo.breadthfirst

Breadth-First algorithm implementation.

Classes: BreadthFirst: Breadth-First spanning algorithm.

BreadthFirst

Bases: SpanningTreeGenerator

Breadth-First algorithm.

Uses the breadth-first algorithm to explore a graph.

Attributes:

Name Type Description
explored_last_step list[EffectCharacter]

Characters explored in the last step.
char_explore_order list[EffectCharacter]

Characters in the order they were explored.
complete bool

Whether the algorithm is complete.
Source code in terminaltexteffects/utils/spanningtree/algo/breadthfirst.py 
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
class BreadthFirst(SpanningTreeGenerator):
    """Breadth-First algorithm.

    Uses the breadth-first algorithm to explore a graph.

    Attributes:
        explored_last_step (list[EffectCharacter]): Characters explored in the last step.
        char_explore_order (list[EffectCharacter]): Characters in the order they were explored.
        complete (bool): Whether the algorithm is complete.

    """

    def __init__(
        self,
        terminal: Terminal,
        starting_char: EffectCharacter | None = None,
        *,
        limit_to_text_boundary: bool = False,
    ) -> None:
        """Initialize the algorithm.

        Args:
            terminal (Terminal): TTE Terminal.
            starting_char (EffectCharacter | None, optional): Starting EffectCharacter. Defaults to None.
            limit_to_text_boundary (bool, optional): If True, the starting character, if not provided, will
                be chosen within the text boundary. This should be True of the spanning tree was generated
                with limit_to_text_boundary=True.

        Raises:
            ValueError: Unable to find a starting character.

        """
        super().__init__(terminal)
        self._limit_to_text_boundary = limit_to_text_boundary
        self.starting_char = starting_char or terminal.get_character_by_input_coord(
            terminal.canvas.random_coord(within_text_boundary=limit_to_text_boundary),
        )
        if starting_char is None:
            msg = "Unable to find a starting character."
            raise ValueError(msg)
        self._frontier = [starting_char]
        self._explored: dict[EffectCharacter, EffectCharacter] = {starting_char: starting_char}
        self.explored_last_step: list[EffectCharacter] = []
        self.char_explore_order: list[EffectCharacter] = []
        self.complete = False

    def step(self) -> None:
        """Perform a single step of the algorithm."""
        self.explored_last_step.clear()
        if not self._frontier:
            self.complete = True
            return
        new_edges = []
        while self._frontier:
            position = self._frontier.pop(0)
            new_edges.extend(
                [
                    neighbor
                    for neighbor in position.links
                    if neighbor not in self._explored and neighbor not in self._frontier
                ],
            )
            for character in new_edges:
                self._explored[character] = position
                self.explored_last_step.append(character)
                self.char_explore_order.append(character)
        self._frontier.extend(new_edges)

__init__(terminal, starting_char=None, *, limit_to_text_boundary=False)

Initialize the algorithm.

Parameters:

Name Type Description Default
terminal Terminal

TTE Terminal.

 required
starting_char EffectCharacter | None

Starting EffectCharacter. Defaults to None.

 None
limit_to_text_boundary bool

If True, the starting character, if not provided, will be chosen within the text boundary. This should be True of the spanning tree was generated with limit_to_text_boundary=True.

 False

Raises:

Type Description
ValueError

Unable to find a starting character.
Source code in terminaltexteffects/utils/spanningtree/algo/breadthfirst.py 
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
def __init__(
    self,
    terminal: Terminal,
    starting_char: EffectCharacter | None = None,
    *,
    limit_to_text_boundary: bool = False,
) -> None:
    """Initialize the algorithm.

    Args:
        terminal (Terminal): TTE Terminal.
        starting_char (EffectCharacter | None, optional): Starting EffectCharacter. Defaults to None.
        limit_to_text_boundary (bool, optional): If True, the starting character, if not provided, will
            be chosen within the text boundary. This should be True of the spanning tree was generated
            with limit_to_text_boundary=True.

    Raises:
        ValueError: Unable to find a starting character.

    """
    super().__init__(terminal)
    self._limit_to_text_boundary = limit_to_text_boundary
    self.starting_char = starting_char or terminal.get_character_by_input_coord(
        terminal.canvas.random_coord(within_text_boundary=limit_to_text_boundary),
    )
    if starting_char is None:
        msg = "Unable to find a starting character."
        raise ValueError(msg)
    self._frontier = [starting_char]
    self._explored: dict[EffectCharacter, EffectCharacter] = {starting_char: starting_char}
    self.explored_last_step: list[EffectCharacter] = []
    self.char_explore_order: list[EffectCharacter] = []
    self.complete = False

step()

Perform a single step of the algorithm.

Source code in terminaltexteffects/utils/spanningtree/algo/breadthfirst.py 
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
def step(self) -> None:
    """Perform a single step of the algorithm."""
    self.explored_last_step.clear()
    if not self._frontier:
        self.complete = True
        return
    new_edges = []
    while self._frontier:
        position = self._frontier.pop(0)
        new_edges.extend(
            [
                neighbor
                for neighbor in position.links
                if neighbor not in self._explored and neighbor not in self._frontier
            ],
        )
        for character in new_edges:
            self._explored[character] = position
            self.explored_last_step.append(character)
            self.char_explore_order.append(character)
    self._frontier.extend(new_edges)