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authorS. Solomon Darnell2025-03-28 21:52:21 -0500
committerS. Solomon Darnell2025-03-28 21:52:21 -0500
commit4a52a71956a8d46fcb7294ac71734504bb09bcc2 (patch)
treeee3dc5af3b6313e921cd920906356f5d4febc4ed /.venv/lib/python3.12/site-packages/pip/_vendor/rich/style.py
parentcc961e04ba734dd72309fb548a2f97d67d578813 (diff)
downloadgn-ai-master.tar.gz
two version of R2R are here HEAD master
Diffstat (limited to '.venv/lib/python3.12/site-packages/pip/_vendor/rich/style.py')
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+import sys
+from functools import lru_cache
+from marshal import dumps, loads
+from random import randint
+from typing import Any, Dict, Iterable, List, Optional, Type, Union, cast
+
+from . import errors
+from .color import Color, ColorParseError, ColorSystem, blend_rgb
+from .repr import Result, rich_repr
+from .terminal_theme import DEFAULT_TERMINAL_THEME, TerminalTheme
+
+# Style instances and style definitions are often interchangeable
+StyleType = Union[str, "Style"]
+
+
+class _Bit:
+    """A descriptor to get/set a style attribute bit."""
+
+    __slots__ = ["bit"]
+
+    def __init__(self, bit_no: int) -> None:
+        self.bit = 1 << bit_no
+
+    def __get__(self, obj: "Style", objtype: Type["Style"]) -> Optional[bool]:
+        if obj._set_attributes & self.bit:
+            return obj._attributes & self.bit != 0
+        return None
+
+
+@rich_repr
+class Style:
+    """A terminal style.
+
+    A terminal style consists of a color (`color`), a background color (`bgcolor`), and a number of attributes, such
+    as bold, italic etc. The attributes have 3 states: they can either be on
+    (``True``), off (``False``), or not set (``None``).
+
+    Args:
+        color (Union[Color, str], optional): Color of terminal text. Defaults to None.
+        bgcolor (Union[Color, str], optional): Color of terminal background. Defaults to None.
+        bold (bool, optional): Enable bold text. Defaults to None.
+        dim (bool, optional): Enable dim text. Defaults to None.
+        italic (bool, optional): Enable italic text. Defaults to None.
+        underline (bool, optional): Enable underlined text. Defaults to None.
+        blink (bool, optional): Enabled blinking text. Defaults to None.
+        blink2 (bool, optional): Enable fast blinking text. Defaults to None.
+        reverse (bool, optional): Enabled reverse text. Defaults to None.
+        conceal (bool, optional): Enable concealed text. Defaults to None.
+        strike (bool, optional): Enable strikethrough text. Defaults to None.
+        underline2 (bool, optional): Enable doubly underlined text. Defaults to None.
+        frame (bool, optional): Enable framed text. Defaults to None.
+        encircle (bool, optional): Enable encircled text. Defaults to None.
+        overline (bool, optional): Enable overlined text. Defaults to None.
+        link (str, link): Link URL. Defaults to None.
+
+    """
+
+    _color: Optional[Color]
+    _bgcolor: Optional[Color]
+    _attributes: int
+    _set_attributes: int
+    _hash: Optional[int]
+    _null: bool
+    _meta: Optional[bytes]
+
+    __slots__ = [
+        "_color",
+        "_bgcolor",
+        "_attributes",
+        "_set_attributes",
+        "_link",
+        "_link_id",
+        "_ansi",
+        "_style_definition",
+        "_hash",
+        "_null",
+        "_meta",
+    ]
+
+    # maps bits on to SGR parameter
+    _style_map = {
+        0: "1",
+        1: "2",
+        2: "3",
+        3: "4",
+        4: "5",
+        5: "6",
+        6: "7",
+        7: "8",
+        8: "9",
+        9: "21",
+        10: "51",
+        11: "52",
+        12: "53",
+    }
+
+    STYLE_ATTRIBUTES = {
+        "dim": "dim",
+        "d": "dim",
+        "bold": "bold",
+        "b": "bold",
+        "italic": "italic",
+        "i": "italic",
+        "underline": "underline",
+        "u": "underline",
+        "blink": "blink",
+        "blink2": "blink2",
+        "reverse": "reverse",
+        "r": "reverse",
+        "conceal": "conceal",
+        "c": "conceal",
+        "strike": "strike",
+        "s": "strike",
+        "underline2": "underline2",
+        "uu": "underline2",
+        "frame": "frame",
+        "encircle": "encircle",
+        "overline": "overline",
+        "o": "overline",
+    }
+
+    def __init__(
+        self,
+        *,
+        color: Optional[Union[Color, str]] = None,
+        bgcolor: Optional[Union[Color, str]] = None,
+        bold: Optional[bool] = None,
+        dim: Optional[bool] = None,
+        italic: Optional[bool] = None,
+        underline: Optional[bool] = None,
+        blink: Optional[bool] = None,
+        blink2: Optional[bool] = None,
+        reverse: Optional[bool] = None,
+        conceal: Optional[bool] = None,
+        strike: Optional[bool] = None,
+        underline2: Optional[bool] = None,
+        frame: Optional[bool] = None,
+        encircle: Optional[bool] = None,
+        overline: Optional[bool] = None,
+        link: Optional[str] = None,
+        meta: Optional[Dict[str, Any]] = None,
+    ):
+        self._ansi: Optional[str] = None
+        self._style_definition: Optional[str] = None
+
+        def _make_color(color: Union[Color, str]) -> Color:
+            return color if isinstance(color, Color) else Color.parse(color)
+
+        self._color = None if color is None else _make_color(color)
+        self._bgcolor = None if bgcolor is None else _make_color(bgcolor)
+        self._set_attributes = sum(
+            (
+                bold is not None,
+                dim is not None and 2,
+                italic is not None and 4,
+                underline is not None and 8,
+                blink is not None and 16,
+                blink2 is not None and 32,
+                reverse is not None and 64,
+                conceal is not None and 128,
+                strike is not None and 256,
+                underline2 is not None and 512,
+                frame is not None and 1024,
+                encircle is not None and 2048,
+                overline is not None and 4096,
+            )
+        )
+        self._attributes = (
+            sum(
+                (
+                    bold and 1 or 0,
+                    dim and 2 or 0,
+                    italic and 4 or 0,
+                    underline and 8 or 0,
+                    blink and 16 or 0,
+                    blink2 and 32 or 0,
+                    reverse and 64 or 0,
+                    conceal and 128 or 0,
+                    strike and 256 or 0,
+                    underline2 and 512 or 0,
+                    frame and 1024 or 0,
+                    encircle and 2048 or 0,
+                    overline and 4096 or 0,
+                )
+            )
+            if self._set_attributes
+            else 0
+        )
+
+        self._link = link
+        self._meta = None if meta is None else dumps(meta)
+        self._link_id = (
+            f"{randint(0, 999999)}{hash(self._meta)}" if (link or meta) else ""
+        )
+        self._hash: Optional[int] = None
+        self._null = not (self._set_attributes or color or bgcolor or link or meta)
+
+    @classmethod
+    def null(cls) -> "Style":
+        """Create an 'null' style, equivalent to Style(), but more performant."""
+        return NULL_STYLE
+
+    @classmethod
+    def from_color(
+        cls, color: Optional[Color] = None, bgcolor: Optional[Color] = None
+    ) -> "Style":
+        """Create a new style with colors and no attributes.
+
+        Returns:
+            color (Optional[Color]): A (foreground) color, or None for no color. Defaults to None.
+            bgcolor (Optional[Color]): A (background) color, or None for no color. Defaults to None.
+        """
+        style: Style = cls.__new__(Style)
+        style._ansi = None
+        style._style_definition = None
+        style._color = color
+        style._bgcolor = bgcolor
+        style._set_attributes = 0
+        style._attributes = 0
+        style._link = None
+        style._link_id = ""
+        style._meta = None
+        style._null = not (color or bgcolor)
+        style._hash = None
+        return style
+
+    @classmethod
+    def from_meta(cls, meta: Optional[Dict[str, Any]]) -> "Style":
+        """Create a new style with meta data.
+
+        Returns:
+            meta (Optional[Dict[str, Any]]): A dictionary of meta data. Defaults to None.
+        """
+        style: Style = cls.__new__(Style)
+        style._ansi = None
+        style._style_definition = None
+        style._color = None
+        style._bgcolor = None
+        style._set_attributes = 0
+        style._attributes = 0
+        style._link = None
+        style._meta = dumps(meta)
+        style._link_id = f"{randint(0, 999999)}{hash(style._meta)}"
+        style._hash = None
+        style._null = not (meta)
+        return style
+
+    @classmethod
+    def on(cls, meta: Optional[Dict[str, Any]] = None, **handlers: Any) -> "Style":
+        """Create a blank style with meta information.
+
+        Example:
+            style = Style.on(click=self.on_click)
+
+        Args:
+            meta (Optional[Dict[str, Any]], optional): An optional dict of meta information.
+            **handlers (Any): Keyword arguments are translated in to handlers.
+
+        Returns:
+            Style: A Style with meta information attached.
+        """
+        meta = {} if meta is None else meta
+        meta.update({f"@{key}": value for key, value in handlers.items()})
+        return cls.from_meta(meta)
+
+    bold = _Bit(0)
+    dim = _Bit(1)
+    italic = _Bit(2)
+    underline = _Bit(3)
+    blink = _Bit(4)
+    blink2 = _Bit(5)
+    reverse = _Bit(6)
+    conceal = _Bit(7)
+    strike = _Bit(8)
+    underline2 = _Bit(9)
+    frame = _Bit(10)
+    encircle = _Bit(11)
+    overline = _Bit(12)
+
+    @property
+    def link_id(self) -> str:
+        """Get a link id, used in ansi code for links."""
+        return self._link_id
+
+    def __str__(self) -> str:
+        """Re-generate style definition from attributes."""
+        if self._style_definition is None:
+            attributes: List[str] = []
+            append = attributes.append
+            bits = self._set_attributes
+            if bits & 0b0000000001111:
+                if bits & 1:
+                    append("bold" if self.bold else "not bold")
+                if bits & (1 << 1):
+                    append("dim" if self.dim else "not dim")
+                if bits & (1 << 2):
+                    append("italic" if self.italic else "not italic")
+                if bits & (1 << 3):
+                    append("underline" if self.underline else "not underline")
+            if bits & 0b0000111110000:
+                if bits & (1 << 4):
+                    append("blink" if self.blink else "not blink")
+                if bits & (1 << 5):
+                    append("blink2" if self.blink2 else "not blink2")
+                if bits & (1 << 6):
+                    append("reverse" if self.reverse else "not reverse")
+                if bits & (1 << 7):
+                    append("conceal" if self.conceal else "not conceal")
+                if bits & (1 << 8):
+                    append("strike" if self.strike else "not strike")
+            if bits & 0b1111000000000:
+                if bits & (1 << 9):
+                    append("underline2" if self.underline2 else "not underline2")
+                if bits & (1 << 10):
+                    append("frame" if self.frame else "not frame")
+                if bits & (1 << 11):
+                    append("encircle" if self.encircle else "not encircle")
+                if bits & (1 << 12):
+                    append("overline" if self.overline else "not overline")
+            if self._color is not None:
+                append(self._color.name)
+            if self._bgcolor is not None:
+                append("on")
+                append(self._bgcolor.name)
+            if self._link:
+                append("link")
+                append(self._link)
+            self._style_definition = " ".join(attributes) or "none"
+        return self._style_definition
+
+    def __bool__(self) -> bool:
+        """A Style is false if it has no attributes, colors, or links."""
+        return not self._null
+
+    def _make_ansi_codes(self, color_system: ColorSystem) -> str:
+        """Generate ANSI codes for this style.
+
+        Args:
+            color_system (ColorSystem): Color system.
+
+        Returns:
+            str: String containing codes.
+        """
+
+        if self._ansi is None:
+            sgr: List[str] = []
+            append = sgr.append
+            _style_map = self._style_map
+            attributes = self._attributes & self._set_attributes
+            if attributes:
+                if attributes & 1:
+                    append(_style_map[0])
+                if attributes & 2:
+                    append(_style_map[1])
+                if attributes & 4:
+                    append(_style_map[2])
+                if attributes & 8:
+                    append(_style_map[3])
+                if attributes & 0b0000111110000:
+                    for bit in range(4, 9):
+                        if attributes & (1 << bit):
+                            append(_style_map[bit])
+                if attributes & 0b1111000000000:
+                    for bit in range(9, 13):
+                        if attributes & (1 << bit):
+                            append(_style_map[bit])
+            if self._color is not None:
+                sgr.extend(self._color.downgrade(color_system).get_ansi_codes())
+            if self._bgcolor is not None:
+                sgr.extend(
+                    self._bgcolor.downgrade(color_system).get_ansi_codes(
+                        foreground=False
+                    )
+                )
+            self._ansi = ";".join(sgr)
+        return self._ansi
+
+    @classmethod
+    @lru_cache(maxsize=1024)
+    def normalize(cls, style: str) -> str:
+        """Normalize a style definition so that styles with the same effect have the same string
+        representation.
+
+        Args:
+            style (str): A style definition.
+
+        Returns:
+            str: Normal form of style definition.
+        """
+        try:
+            return str(cls.parse(style))
+        except errors.StyleSyntaxError:
+            return style.strip().lower()
+
+    @classmethod
+    def pick_first(cls, *values: Optional[StyleType]) -> StyleType:
+        """Pick first non-None style."""
+        for value in values:
+            if value is not None:
+                return value
+        raise ValueError("expected at least one non-None style")
+
+    def __rich_repr__(self) -> Result:
+        yield "color", self.color, None
+        yield "bgcolor", self.bgcolor, None
+        yield "bold", self.bold, None,
+        yield "dim", self.dim, None,
+        yield "italic", self.italic, None
+        yield "underline", self.underline, None,
+        yield "blink", self.blink, None
+        yield "blink2", self.blink2, None
+        yield "reverse", self.reverse, None
+        yield "conceal", self.conceal, None
+        yield "strike", self.strike, None
+        yield "underline2", self.underline2, None
+        yield "frame", self.frame, None
+        yield "encircle", self.encircle, None
+        yield "link", self.link, None
+        if self._meta:
+            yield "meta", self.meta
+
+    def __eq__(self, other: Any) -> bool:
+        if not isinstance(other, Style):
+            return NotImplemented
+        return self.__hash__() == other.__hash__()
+
+    def __ne__(self, other: Any) -> bool:
+        if not isinstance(other, Style):
+            return NotImplemented
+        return self.__hash__() != other.__hash__()
+
+    def __hash__(self) -> int:
+        if self._hash is not None:
+            return self._hash
+        self._hash = hash(
+            (
+                self._color,
+                self._bgcolor,
+                self._attributes,
+                self._set_attributes,
+                self._link,
+                self._meta,
+            )
+        )
+        return self._hash
+
+    @property
+    def color(self) -> Optional[Color]:
+        """The foreground color or None if it is not set."""
+        return self._color
+
+    @property
+    def bgcolor(self) -> Optional[Color]:
+        """The background color or None if it is not set."""
+        return self._bgcolor
+
+    @property
+    def link(self) -> Optional[str]:
+        """Link text, if set."""
+        return self._link
+
+    @property
+    def transparent_background(self) -> bool:
+        """Check if the style specified a transparent background."""
+        return self.bgcolor is None or self.bgcolor.is_default
+
+    @property
+    def background_style(self) -> "Style":
+        """A Style with background only."""
+        return Style(bgcolor=self.bgcolor)
+
+    @property
+    def meta(self) -> Dict[str, Any]:
+        """Get meta information (can not be changed after construction)."""
+        return {} if self._meta is None else cast(Dict[str, Any], loads(self._meta))
+
+    @property
+    def without_color(self) -> "Style":
+        """Get a copy of the style with color removed."""
+        if self._null:
+            return NULL_STYLE
+        style: Style = self.__new__(Style)
+        style._ansi = None
+        style._style_definition = None
+        style._color = None
+        style._bgcolor = None
+        style._attributes = self._attributes
+        style._set_attributes = self._set_attributes
+        style._link = self._link
+        style._link_id = f"{randint(0, 999999)}" if self._link else ""
+        style._null = False
+        style._meta = None
+        style._hash = None
+        return style
+
+    @classmethod
+    @lru_cache(maxsize=4096)
+    def parse(cls, style_definition: str) -> "Style":
+        """Parse a style definition.
+
+        Args:
+            style_definition (str): A string containing a style.
+
+        Raises:
+            errors.StyleSyntaxError: If the style definition syntax is invalid.
+
+        Returns:
+            `Style`: A Style instance.
+        """
+        if style_definition.strip() == "none" or not style_definition:
+            return cls.null()
+
+        STYLE_ATTRIBUTES = cls.STYLE_ATTRIBUTES
+        color: Optional[str] = None
+        bgcolor: Optional[str] = None
+        attributes: Dict[str, Optional[Any]] = {}
+        link: Optional[str] = None
+
+        words = iter(style_definition.split())
+        for original_word in words:
+            word = original_word.lower()
+            if word == "on":
+                word = next(words, "")
+                if not word:
+                    raise errors.StyleSyntaxError("color expected after 'on'")
+                try:
+                    Color.parse(word) is None
+                except ColorParseError as error:
+                    raise errors.StyleSyntaxError(
+                        f"unable to parse {word!r} as background color; {error}"
+                    ) from None
+                bgcolor = word
+
+            elif word == "not":
+                word = next(words, "")
+                attribute = STYLE_ATTRIBUTES.get(word)
+                if attribute is None:
+                    raise errors.StyleSyntaxError(
+                        f"expected style attribute after 'not', found {word!r}"
+                    )
+                attributes[attribute] = False
+
+            elif word == "link":
+                word = next(words, "")
+                if not word:
+                    raise errors.StyleSyntaxError("URL expected after 'link'")
+                link = word
+
+            elif word in STYLE_ATTRIBUTES:
+                attributes[STYLE_ATTRIBUTES[word]] = True
+
+            else:
+                try:
+                    Color.parse(word)
+                except ColorParseError as error:
+                    raise errors.StyleSyntaxError(
+                        f"unable to parse {word!r} as color; {error}"
+                    ) from None
+                color = word
+        style = Style(color=color, bgcolor=bgcolor, link=link, **attributes)
+        return style
+
+    @lru_cache(maxsize=1024)
+    def get_html_style(self, theme: Optional[TerminalTheme] = None) -> str:
+        """Get a CSS style rule."""
+        theme = theme or DEFAULT_TERMINAL_THEME
+        css: List[str] = []
+        append = css.append
+
+        color = self.color
+        bgcolor = self.bgcolor
+        if self.reverse:
+            color, bgcolor = bgcolor, color
+        if self.dim:
+            foreground_color = (
+                theme.foreground_color if color is None else color.get_truecolor(theme)
+            )
+            color = Color.from_triplet(
+                blend_rgb(foreground_color, theme.background_color, 0.5)
+            )
+        if color is not None:
+            theme_color = color.get_truecolor(theme)
+            append(f"color: {theme_color.hex}")
+            append(f"text-decoration-color: {theme_color.hex}")
+        if bgcolor is not None:
+            theme_color = bgcolor.get_truecolor(theme, foreground=False)
+            append(f"background-color: {theme_color.hex}")
+        if self.bold:
+            append("font-weight: bold")
+        if self.italic:
+            append("font-style: italic")
+        if self.underline:
+            append("text-decoration: underline")
+        if self.strike:
+            append("text-decoration: line-through")
+        if self.overline:
+            append("text-decoration: overline")
+        return "; ".join(css)
+
+    @classmethod
+    def combine(cls, styles: Iterable["Style"]) -> "Style":
+        """Combine styles and get result.
+
+        Args:
+            styles (Iterable[Style]): Styles to combine.
+
+        Returns:
+            Style: A new style instance.
+        """
+        iter_styles = iter(styles)
+        return sum(iter_styles, next(iter_styles))
+
+    @classmethod
+    def chain(cls, *styles: "Style") -> "Style":
+        """Combine styles from positional argument in to a single style.
+
+        Args:
+            *styles (Iterable[Style]): Styles to combine.
+
+        Returns:
+            Style: A new style instance.
+        """
+        iter_styles = iter(styles)
+        return sum(iter_styles, next(iter_styles))
+
+    def copy(self) -> "Style":
+        """Get a copy of this style.
+
+        Returns:
+            Style: A new Style instance with identical attributes.
+        """
+        if self._null:
+            return NULL_STYLE
+        style: Style = self.__new__(Style)
+        style._ansi = self._ansi
+        style._style_definition = self._style_definition
+        style._color = self._color
+        style._bgcolor = self._bgcolor
+        style._attributes = self._attributes
+        style._set_attributes = self._set_attributes
+        style._link = self._link
+        style._link_id = f"{randint(0, 999999)}" if self._link else ""
+        style._hash = self._hash
+        style._null = False
+        style._meta = self._meta
+        return style
+
+    @lru_cache(maxsize=128)
+    def clear_meta_and_links(self) -> "Style":
+        """Get a copy of this style with link and meta information removed.
+
+        Returns:
+            Style: New style object.
+        """
+        if self._null:
+            return NULL_STYLE
+        style: Style = self.__new__(Style)
+        style._ansi = self._ansi
+        style._style_definition = self._style_definition
+        style._color = self._color
+        style._bgcolor = self._bgcolor
+        style._attributes = self._attributes
+        style._set_attributes = self._set_attributes
+        style._link = None
+        style._link_id = ""
+        style._hash = None
+        style._null = False
+        style._meta = None
+        return style
+
+    def update_link(self, link: Optional[str] = None) -> "Style":
+        """Get a copy with a different value for link.
+
+        Args:
+            link (str, optional): New value for link. Defaults to None.
+
+        Returns:
+            Style: A new Style instance.
+        """
+        style: Style = self.__new__(Style)
+        style._ansi = self._ansi
+        style._style_definition = self._style_definition
+        style._color = self._color
+        style._bgcolor = self._bgcolor
+        style._attributes = self._attributes
+        style._set_attributes = self._set_attributes
+        style._link = link
+        style._link_id = f"{randint(0, 999999)}" if link else ""
+        style._hash = None
+        style._null = False
+        style._meta = self._meta
+        return style
+
+    def render(
+        self,
+        text: str = "",
+        *,
+        color_system: Optional[ColorSystem] = ColorSystem.TRUECOLOR,
+        legacy_windows: bool = False,
+    ) -> str:
+        """Render the ANSI codes for the style.
+
+        Args:
+            text (str, optional): A string to style. Defaults to "".
+            color_system (Optional[ColorSystem], optional): Color system to render to. Defaults to ColorSystem.TRUECOLOR.
+
+        Returns:
+            str: A string containing ANSI style codes.
+        """
+        if not text or color_system is None:
+            return text
+        attrs = self._ansi or self._make_ansi_codes(color_system)
+        rendered = f"\x1b[{attrs}m{text}\x1b[0m" if attrs else text
+        if self._link and not legacy_windows:
+            rendered = (
+                f"\x1b]8;id={self._link_id};{self._link}\x1b\\{rendered}\x1b]8;;\x1b\\"
+            )
+        return rendered
+
+    def test(self, text: Optional[str] = None) -> None:
+        """Write text with style directly to terminal.
+
+        This method is for testing purposes only.
+
+        Args:
+            text (Optional[str], optional): Text to style or None for style name.
+
+        """
+        text = text or str(self)
+        sys.stdout.write(f"{self.render(text)}\n")
+
+    @lru_cache(maxsize=1024)
+    def _add(self, style: Optional["Style"]) -> "Style":
+        if style is None or style._null:
+            return self
+        if self._null:
+            return style
+        new_style: Style = self.__new__(Style)
+        new_style._ansi = None
+        new_style._style_definition = None
+        new_style._color = style._color or self._color
+        new_style._bgcolor = style._bgcolor or self._bgcolor
+        new_style._attributes = (self._attributes & ~style._set_attributes) | (
+            style._attributes & style._set_attributes
+        )
+        new_style._set_attributes = self._set_attributes | style._set_attributes
+        new_style._link = style._link or self._link
+        new_style._link_id = style._link_id or self._link_id
+        new_style._null = style._null
+        if self._meta and style._meta:
+            new_style._meta = dumps({**self.meta, **style.meta})
+        else:
+            new_style._meta = self._meta or style._meta
+        new_style._hash = None
+        return new_style
+
+    def __add__(self, style: Optional["Style"]) -> "Style":
+        combined_style = self._add(style)
+        return combined_style.copy() if combined_style.link else combined_style
+
+
+NULL_STYLE = Style()
+
+
+class StyleStack:
+    """A stack of styles."""
+
+    __slots__ = ["_stack"]
+
+    def __init__(self, default_style: "Style") -> None:
+        self._stack: List[Style] = [default_style]
+
+    def __repr__(self) -> str:
+        return f"<stylestack {self._stack!r}>"
+
+    @property
+    def current(self) -> Style:
+        """Get the Style at the top of the stack."""
+        return self._stack[-1]
+
+    def push(self, style: Style) -> None:
+        """Push a new style on to the stack.
+
+        Args:
+            style (Style): New style to combine with current style.
+        """
+        self._stack.append(self._stack[-1] + style)
+
+    def pop(self) -> Style:
+        """Pop last style and discard.
+
+        Returns:
+            Style: New current style (also available as stack.current)
+        """
+        self._stack.pop()
+        return self._stack[-1]