AsciiCanvas Class — langchain Architecture

Source Code

libs/core/langchain_core/runnables/graph_ascii.py lines 57–190

class AsciiCanvas:
    """Class for drawing in ASCII."""

    TIMEOUT = 10

    def __init__(self, cols: int, lines: int) -> None:
        """Create an ASCII canvas.

        Args:
            cols: number of columns in the canvas. Should be `> 1`.
            lines: number of lines in the canvas. Should be `> 1`.

        Raises:
            ValueError: if canvas dimensions are invalid.
        """
        if cols <= 1 or lines <= 1:
            msg = "Canvas dimensions should be > 1"
            raise ValueError(msg)

        self.cols = cols
        self.lines = lines

        self.canvas = [[" "] * cols for line in range(lines)]

    def draw(self) -> str:
        """Draws ASCII canvas on the screen.

        Returns:
            The ASCII canvas string.
        """
        lines = map("".join, self.canvas)
        return os.linesep.join(lines)

    def point(self, x: int, y: int, char: str) -> None:
        """Create a point on ASCII canvas.

        Args:
            x: x coordinate. Should be `>= 0` and `<` number of columns in
                the canvas.
            y: y coordinate. Should be `>= 0` an `<` number of lines in the
                canvas.
            char: character to place in the specified point on the
                canvas.

        Raises:
            ValueError: if char is not a single character or if
                coordinates are out of bounds.
        """
        if len(char) != 1:
            msg = "char should be a single character"
            raise ValueError(msg)
        if x >= self.cols or x < 0:
            msg = "x should be >= 0 and < number of columns"
            raise ValueError(msg)
        if y >= self.lines or y < 0:
            msg = "y should be >= 0 and < number of lines"
            raise ValueError(msg)

        self.canvas[y][x] = char

    def line(self, x0: int, y0: int, x1: int, y1: int, char: str) -> None:
        """Create a line on ASCII canvas.

        Args:
            x0: x coordinate where the line should start.
            y0: y coordinate where the line should start.
            x1: x coordinate where the line should end.
            y1: y coordinate where the line should end.
            char: character to draw the line with.
        """
        if x0 > x1:
            x1, x0 = x0, x1
            y1, y0 = y0, y1

        dx = x1 - x0
        dy = y1 - y0

        if dx == 0 and dy == 0:
            self.point(x0, y0, char)
        elif abs(dx) >= abs(dy):
            for x in range(x0, x1 + 1):