import urllib.parse


class PackageIndex:
    """Represents a Package Index and provides easier access to endpoints"""

    __slots__ = ["url", "netloc", "simple_url", "pypi_url", "file_storage_domain"]

    def __init__(self, url: str, file_storage_domain: str) -> None:
        super().__init__()
        self.url = url
        self.netloc = urllib.parse.urlsplit(url).netloc
        self.simple_url = self._url_for_path("simple")
        self.pypi_url = self._url_for_path("pypi")

        # This is part of a temporary hack used to block installs of PyPI
        # packages which depend on external urls only necessary until PyPI can
        # block such packages themselves
        self.file_storage_domain = file_storage_domain

    def _url_for_path(self, path: str) -> str:
        return urllib.parse.urljoin(self.url, path)


PyPI = PackageIndex("https://pypi.org/", file_storage_domain="files.pythonhosted.org")
TestPyPI = PackageIndex(
    "https://test.pypi.org/", file_storage_domain="test-files.pythonhosted.org"
)

"""
requests.exceptions
~~~~~~~~~~~~~~~~~~~

This module contains the set of Requests' exceptions.
"""
from pip._vendor.urllib3.exceptions import HTTPError as BaseHTTPError

from .compat import JSONDecodeError as CompatJSONDecodeError


class RequestException(IOError):
    """There was an ambiguous exception that occurred while handling your
    request.
    """

    def __init__(self, *args, **kwargs):
        """Initialize RequestException with `request` and `response` objects."""
        response = kwargs.pop("response", None)
        self.response = response
        self.request = kwargs.pop("request", None)
        if response is not None and not self.request and hasattr(response, "request"):
            self.request = self.response.request
        super().__init__(*args, **kwargs)


class InvalidJSONError(RequestException):
    """A JSON error occurred."""


class JSONDecodeError(InvalidJSONError, CompatJSONDecodeError):
    """Couldn't decode the text into json"""

    def __init__(self, *args, **kwargs):
        """
        Construct the JSONDecodeError instance first with all
        args. Then use it's args to construct the IOError so that
        the json specific args aren't used as IOError specific args
        and the error message from JSONDecodeError is preserved.
        """
        CompatJSONDecodeError.__init__(self, *args)
        InvalidJSONError.__init__(self, *self.args, **kwargs)

    def __reduce__(self):
        """
        The __reduce__ method called when pickling the object must
        be the one from the JSONDecodeError (be it json/simplejson)
        as it expects all the arguments for instantiation, not just
        one like the IOError, and the MRO would by default call the
        __reduce__ method from the IOError due to the inheritance order.
        """
        return CompatJSONDecodeError.__reduce__(self)


class HTTPError(RequestException):
    """An HTTP error occurred."""


class ConnectionError(RequestException):
    """A Connection error occurred."""


class ProxyError(ConnectionError):
    """A proxy error occurred."""


class SSLError(ConnectionError):
    """An SSL error occurred."""


class Timeout(RequestException):
    """The request timed out.

    Catching this error will catch both
    :exc:`~requests.exceptions.ConnectTimeout` and
    :exc:`~requests.exceptions.ReadTimeout` errors.
    """


class ConnectTimeout(ConnectionError, Timeout):
    """The request timed out while trying to connect to the remote server.

    Requests that produced this error are safe to retry.
    """


class ReadTimeout(Timeout):
    """The server did not send any data in the allotted amount of time."""


class URLRequired(RequestException):
    """A valid URL is required to make a request."""


class TooManyRedirects(RequestException):
    """Too many redirects."""


class MissingSchema(RequestException, ValueError):
    """The URL scheme (e.g. http or https) is missing."""


class InvalidSchema(RequestException, ValueError):
    """The URL scheme provided is either invalid or unsupported."""


class InvalidURL(RequestException, ValueError):
    """The URL provided was somehow invalid."""


class InvalidHeader(RequestException, ValueError):
    """The header value provided was somehow invalid."""


class InvalidProxyURL(InvalidURL):
    """The proxy URL provided is invalid."""


class ChunkedEncodingError(RequestException):
    """The server declared chunked encoding but sent an invalid chunk."""


class ContentDecodingError(RequestException, BaseHTTPError):
    """Failed to decode response content."""


class StreamConsumedError(RequestException, TypeError):
    """The content for this response was already consumed."""


class RetryError(RequestException):
    """Custom retries logic failed"""


class UnrewindableBodyError(RequestException):
    """Requests encountered an error when trying to rewind a body."""


# Warnings


class RequestsWarning(Warning):
    """Base warning for Requests."""


class FileModeWarning(RequestsWarning, DeprecationWarning):
    """A file was opened in text mode, but Requests determined its binary length."""


class RequestsDependencyWarning(RequestsWarning):
    """An imported dependency doesn't match the expected version range."""

import collections
import logging
from dataclasses import dataclass
from typing import Generator, List, Optional, Sequence, Tuple

from pip._internal.utils.logging import indent_log

from .req_file import parse_requirements
from .req_install import InstallRequirement
from .req_set import RequirementSet

__all__ = [
    "RequirementSet",
    "InstallRequirement",
    "parse_requirements",
    "install_given_reqs",
]

logger = logging.getLogger(__name__)


@dataclass(frozen=True)
class InstallationResult:
    name: str


def _validate_requirements(
    requirements: List[InstallRequirement],
) -> Generator[Tuple[str, InstallRequirement], None, None]:
    for req in requirements:
        assert req.name, f"invalid to-be-installed requirement: {req}"
        yield req.name, req


def install_given_reqs(
    requirements: List[InstallRequirement],
    global_options: Sequence[str],
    root: Optional[str],
    home: Optional[str],
    prefix: Optional[str],
    warn_script_location: bool,
    use_user_site: bool,
    pycompile: bool,
) -> List[InstallationResult]:
    """
    Install everything in the given list.

    (to be called after having downloaded and unpacked the packages)
    """
    to_install = collections.OrderedDict(_validate_requirements(requirements))

    if to_install:
        logger.info(
            "Installing collected packages: %s",
            ", ".join(to_install.keys()),
        )

    installed = []

    with indent_log():
        for req_name, requirement in to_install.items():
            if requirement.should_reinstall:
                logger.info("Attempting uninstall: %s", req_name)
                with indent_log():
                    uninstalled_pathset = requirement.uninstall(auto_confirm=True)
            else:
                uninstalled_pathset = None

            try:
                requirement.install(
                    global_options,
                    root=root,
                    home=home,
                    prefix=prefix,
                    warn_script_location=warn_script_location,
                    use_user_site=use_user_site,
                    pycompile=pycompile,
                )
            except Exception:
                # if install did not succeed, rollback previous uninstall
                if uninstalled_pathset and not requirement.install_succeeded:
                    uninstalled_pathset.rollback()
                raise
            else:
                if uninstalled_pathset and requirement.install_succeeded:
                    uninstalled_pathset.commit()

            installed.append(InstallationResult(req_name))

    return installed

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

__title__ = "packaging"
__summary__ = "Core utilities for Python packages"
__uri__ = "https://github.com/pypa/packaging"

__version__ = "24.1"

__author__ = "Donald Stufft and individual contributors"
__email__ = "donald@stufft.io"

__license__ = "BSD-2-Clause or Apache-2.0"
__copyright__ = "2014 %s" % __author__

from typing import Iterable, Tuple, TypeVar

T = TypeVar("T")


def loop_first(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
    """Iterate and generate a tuple with a flag for first value."""
    iter_values = iter(values)
    try:
        value = next(iter_values)
    except StopIteration:
        return
    yield True, value
    for value in iter_values:
        yield False, value


def loop_last(values: Iterable[T]) -> Iterable[Tuple[bool, T]]:
    """Iterate and generate a tuple with a flag for last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    for value in iter_values:
        yield False, previous_value
        previous_value = value
    yield True, previous_value


def loop_first_last(values: Iterable[T]) -> Iterable[Tuple[bool, bool, T]]:
    """Iterate and generate a tuple with a flag for first and last value."""
    iter_values = iter(values)
    try:
        previous_value = next(iter_values)
    except StopIteration:
        return
    first = True
    for value in iter_values:
        yield first, False, previous_value
        first = False
        previous_value = value
    yield first, True, previous_value

import logging
import mimetypes
import os
from collections import defaultdict
from typing import Callable, Dict, Iterable, List, Optional, Tuple

from pip._vendor.packaging.utils import (
    InvalidSdistFilename,
    InvalidWheelFilename,
    canonicalize_name,
    parse_sdist_filename,
    parse_wheel_filename,
)

from pip._internal.models.candidate import InstallationCandidate
from pip._internal.models.link import Link
from pip._internal.utils.urls import path_to_url, url_to_path
from pip._internal.vcs import is_url

logger = logging.getLogger(__name__)

FoundCandidates = Iterable[InstallationCandidate]
FoundLinks = Iterable[Link]
CandidatesFromPage = Callable[[Link], Iterable[InstallationCandidate]]
PageValidator = Callable[[Link], bool]


class LinkSource:
    @property
    def link(self) -> Optional[Link]:
        """Returns the underlying link, if there's one."""
        raise NotImplementedError()

    def page_candidates(self) -> FoundCandidates:
        """Candidates found by parsing an archive listing HTML file."""
        raise NotImplementedError()

    def file_links(self) -> FoundLinks:
        """Links found by specifying archives directly."""
        raise NotImplementedError()


def _is_html_file(file_url: str) -> bool:
    return mimetypes.guess_type(file_url, strict=False)[0] == "text/html"


class _FlatDirectoryToUrls:
    """Scans directory and caches results"""

    def __init__(self, path: str) -> None:
        self._path = path
        self._page_candidates: List[str] = []
        self._project_name_to_urls: Dict[str, List[str]] = defaultdict(list)
        self._scanned_directory = False

    def _scan_directory(self) -> None:
        """Scans directory once and populates both page_candidates
        and project_name_to_urls at the same time
        """
        for entry in os.scandir(self._path):
            url = path_to_url(entry.path)
            if _is_html_file(url):
                self._page_candidates.append(url)
                continue

            # File must have a valid wheel or sdist name,
            # otherwise not worth considering as a package
            try:
                project_filename = parse_wheel_filename(entry.name)[0]
            except InvalidWheelFilename:
                try:
                    project_filename = parse_sdist_filename(entry.name)[0]
                except InvalidSdistFilename:
                    continue

            self._project_name_to_urls[project_filename].append(url)
        self._scanned_directory = True

    @property
    def page_candidates(self) -> List[str]:
        if not self._scanned_directory:
            self._scan_directory()

        return self._page_candidates

    @property
    def project_name_to_urls(self) -> Dict[str, List[str]]:
        if not self._scanned_directory:
            self._scan_directory()

        return self._project_name_to_urls


class _FlatDirectorySource(LinkSource):
    """Link source specified by ``--find-links=<path-to-dir>``.

    This looks the content of the directory, and returns:

    * ``page_candidates``: Links listed on each HTML file in the directory.
    * ``file_candidates``: Archives in the directory.
    """

    _paths_to_urls: Dict[str, _FlatDirectoryToUrls] = {}

    def __init__(
        self,
        candidates_from_page: CandidatesFromPage,
        path: str,
        project_name: str,
    ) -> None:
        self._candidates_from_page = candidates_from_page
        self._project_name = canonicalize_name(project_name)

        # Get existing instance of _FlatDirectoryToUrls if it exists
        if path in self._paths_to_urls:
            self._path_to_urls = self._paths_to_urls[path]
        else:
            self._path_to_urls = _FlatDirectoryToUrls(path=path)
            self._paths_to_urls[path] = self._path_to_urls

    @property
    def link(self) -> Optional[Link]:
        return None

    def page_candidates(self) -> FoundCandidates:
        for url in self._path_to_urls.page_candidates:
            yield from self._candidates_from_page(Link(url))

    def file_links(self) -> FoundLinks:
        for url in self._path_to_urls.project_name_to_urls[self._project_name]:
            yield Link(url)


class _LocalFileSource(LinkSource):
    """``--find-links=<path-or-url>`` or ``--[extra-]index-url=<path-or-url>``.

    If a URL is supplied, it must be a ``file:`` URL. If a path is supplied to
    the option, it is converted to a URL first. This returns:

    * ``page_candidates``: Links listed on an HTML file.
    * ``file_candidates``: The non-HTML file.
    """

    def __init__(
        self,
        candidates_from_page: CandidatesFromPage,
        link: Link,
    ) -> None:
        self._candidates_from_page = candidates_from_page
        self._link = link

    @property
    def link(self) -> Optional[Link]:
        return self._link

    def page_candidates(self) -> FoundCandidates:
        if not _is_html_file(self._link.url):
            return
        yield from self._candidates_from_page(self._link)

    def file_links(self) -> FoundLinks:
        if _is_html_file(self._link.url):
            return
        yield self._link


class _RemoteFileSource(LinkSource):
    """``--find-links=<url>`` or ``--[extra-]index-url=<url>``.

    This returns:

    * ``page_candidates``: Links listed on an HTML file.
    * ``file_candidates``: The non-HTML file.
    """

    def __init__(
        self,
        candidates_from_page: CandidatesFromPage,
        page_validator: PageValidator,
        link: Link,
    ) -> None:
        self._candidates_from_page = candidates_from_page
        self._page_validator = page_validator
        self._link = link

    @property
    def link(self) -> Optional[Link]:
        return self._link

    def page_candidates(self) -> FoundCandidates:
        if not self._page_validator(self._link):
            return
        yield from self._candidates_from_page(self._link)

    def file_links(self) -> FoundLinks:
        yield self._link


class _IndexDirectorySource(LinkSource):
    """``--[extra-]index-url=<path-to-directory>``.

    This is treated like a remote URL; ``candidates_from_page`` contains logic
    for this by appending ``index.html`` to the link.
    """

    def __init__(
        self,
        candidates_from_page: CandidatesFromPage,
        link: Link,
    ) -> None:
        self._candidates_from_page = candidates_from_page
        self._link = link

    @property
    def link(self) -> Optional[Link]:
        return self._link

    def page_candidates(self) -> FoundCandidates:
        yield from self._candidates_from_page(self._link)

    def file_links(self) -> FoundLinks:
        return ()


def build_source(
    location: str,
    *,
    candidates_from_page: CandidatesFromPage,
    page_validator: PageValidator,
    expand_dir: bool,
    cache_link_parsing: bool,
    project_name: str,
) -> Tuple[Optional[str], Optional[LinkSource]]:
    path: Optional[str] = None
    url: Optional[str] = None
    if os.path.exists(location):  # Is a local path.
        url = path_to_url(location)
        path = location
    elif location.startswith("file:"):  # A file: URL.
        url = location
        path = url_to_path(location)
    elif is_url(location):
        url = location

    if url is None:
        msg = (
            "Location '%s' is ignored: "
            "it is either a non-existing path or lacks a specific scheme."
        )
        logger.warning(msg, location)
        return (None, None)

    if path is None:
        source: LinkSource = _RemoteFileSource(
            candidates_from_page=candidates_from_page,
            page_validator=page_validator,
            link=Link(url, cache_link_parsing=cache_link_parsing),
        )
        return (url, source)

    if os.path.isdir(path):
        if expand_dir:
            source = _FlatDirectorySource(
                candidates_from_page=candidates_from_page,
                path=path,
                project_name=project_name,
            )
        else:
            source = _IndexDirectorySource(
                candidates_from_page=candidates_from_page,
                link=Link(url, cache_link_parsing=cache_link_parsing),
            )
        return (url, source)
    elif os.path.isfile(path):
        source = _LocalFileSource(
            candidates_from_page=candidates_from_page,
            link=Link(url, cache_link_parsing=cache_link_parsing),
        )
        return (url, source)
    logger.warning(
        "Location '%s' is ignored: it is neither a file nor a directory.",
        location,
    )
    return (url, None)

CONSOLE_HTML_FORMAT = """\
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<style>
{stylesheet}
body {{
    color: {foreground};
    background-color: {background};
}}
</style>
</head>
<body>
    <pre style="font-family:Menlo,'DejaVu Sans Mono',consolas,'Courier New',monospace"><code style="font-family:inherit">{code}</code></pre>
</body>
</html>
"""

CONSOLE_SVG_FORMAT = """\
<svg class="rich-terminal" viewBox="0 0 {width} {height}" xmlns="http://www.w3.org/2000/svg">
    <!-- Generated with Rich https://www.textualize.io -->
    <style>

    @font-face {{
        font-family: "Fira Code";
        src: local("FiraCode-Regular"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Regular.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Regular.woff") format("woff");
        font-style: normal;
        font-weight: 400;
    }}
    @font-face {{
        font-family: "Fira Code";
        src: local("FiraCode-Bold"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff2/FiraCode-Bold.woff2") format("woff2"),
                url("https://cdnjs.cloudflare.com/ajax/libs/firacode/6.2.0/woff/FiraCode-Bold.woff") format("woff");
        font-style: bold;
        font-weight: 700;
    }}

    .{unique_id}-matrix {{
        font-family: Fira Code, monospace;
        font-size: {char_height}px;
        line-height: {line_height}px;
        font-variant-east-asian: full-width;
    }}

    .{unique_id}-title {{
        font-size: 18px;
        font-weight: bold;
        font-family: arial;
    }}

    {styles}
    </style>

    <defs>
    <clipPath id="{unique_id}-clip-terminal">
      <rect x="0" y="0" width="{terminal_width}" height="{terminal_height}" />
    </clipPath>
    {lines}
    </defs>

    {chrome}
    <g transform="translate({terminal_x}, {terminal_y})" clip-path="url(#{unique_id}-clip-terminal)">
    {backgrounds}
    <g class="{unique_id}-matrix">
    {matrix}
    </g>
    </g>
</svg>
"""

_SVG_FONT_FAMILY = "Rich Fira Code"
_SVG_CLASSES_PREFIX = "rich-svg"

"""
    pygments.token
    ~~~~~~~~~~~~~~

    Basic token types and the standard tokens.

    :copyright: Copyright 2006-2024 by the Pygments team, see AUTHORS.
    :license: BSD, see LICENSE for details.
"""


class _TokenType(tuple):
    parent = None

    def split(self):
        buf = []
        node = self
        while node is not None:
            buf.append(node)
            node = node.parent
        buf.reverse()
        return buf

    def __init__(self, *args):
        # no need to call super.__init__
        self.subtypes = set()

    def __contains__(self, val):
        return self is val or (
            type(val) is self.__class__ and
            val[:len(self)] == self
        )

    def __getattr__(self, val):
        if not val or not val[0].isupper():
            return tuple.__getattribute__(self, val)
        new = _TokenType(self + (val,))
        setattr(self, val, new)
        self.subtypes.add(new)
        new.parent = self
        return new

    def __repr__(self):
        return 'Token' + (self and '.' or '') + '.'.join(self)

    def __copy__(self):
        # These instances are supposed to be singletons
        return self

    def __deepcopy__(self, memo):
        # These instances are supposed to be singletons
        return self


Token = _TokenType()

# Special token types
Text = Token.Text
Whitespace = Text.Whitespace
Escape = Token.Escape
Error = Token.Error
# Text that doesn't belong to this lexer (e.g. HTML in PHP)
Other = Token.Other

# Common token types for source code
Keyword = Token.Keyword
Name = Token.Name
Literal = Token.Literal
String = Literal.String
Number = Literal.Number
Punctuation = Token.Punctuation
Operator = Token.Operator
Comment = Token.Comment

# Generic types for non-source code
Generic = Token.Generic

# String and some others are not direct children of Token.
# alias them:
Token.Token = Token
Token.String = String
Token.Number = Number


def is_token_subtype(ttype, other):
    """
    Return True if ``ttype`` is a subtype of ``other``.

    exists for backwards compatibility. use ``ttype in other`` now.
    """
    return ttype in other


def string_to_tokentype(s):
    """
    Convert a string into a token type::

        >>> string_to_token('String.Double')
        Token.Literal.String.Double
        >>> string_to_token('Token.Literal.Number')
        Token.Literal.Number
        >>> string_to_token('')
        Token

    Tokens that are already tokens are returned unchanged:

        >>> string_to_token(String)
        Token.Literal.String
    """
    if isinstance(s, _TokenType):
        return s
    if not s:
        return Token
    node = Token
    for item in s.split('.'):
        node = getattr(node, item)
    return node


# Map standard token types to short names, used in CSS class naming.
# If you add a new item, please be sure to run this file to perform
# a consistency check for duplicate values.
STANDARD_TYPES = {
    Token:                         '',

    Text:                          '',
    Whitespace:                    'w',
    Escape:                        'esc',
    Error:                         'err',
    Other:                         'x',

    Keyword:                       'k',
    Keyword.Constant:              'kc',
    Keyword.Declaration:           'kd',
    Keyword.Namespace:             'kn',
    Keyword.Pseudo:                'kp',
    Keyword.Reserved:              'kr',
    Keyword.Type:                  'kt',

    Name:                          'n',
    Name.Attribute:                'na',
    Name.Builtin:                  'nb',
    Name.Builtin.Pseudo:           'bp',
    Name.Class:                    'nc',
    Name.Constant:                 'no',
    Name.Decorator:                'nd',
    Name.Entity:                   'ni',
    Name.Exception:                'ne',
    Name.Function:                 'nf',
    Name.Function.Magic:           'fm',
    Name.Property:                 'py',
    Name.Label:                    'nl',
    Name.Namespace:                'nn',
    Name.Other:                    'nx',
    Name.Tag:                      'nt',
    Name.Variable:                 'nv',
    Name.Variable.Class:           'vc',
    Name.Variable.Global:          'vg',
    Name.Variable.Instance:        'vi',
    Name.Variable.Magic:           'vm',

    Literal:                       'l',
    Literal.Date:                  'ld',

    String:                        's',
    String.Affix:                  'sa',
    String.Backtick:               'sb',
    String.Char:                   'sc',
    String.Delimiter:              'dl',
    String.Doc:                    'sd',
    String.Double:                 's2',
    String.Escape:                 'se',
    String.Heredoc:                'sh',
    String.Interpol:               'si',
    String.Other:                  'sx',
    String.Regex:                  'sr',
    String.Single:                 's1',
    String.Symbol:                 'ss',

    Number:                        'm',
    Number.Bin:                    'mb',
    Number.Float:                  'mf',
    Number.Hex:                    'mh',
    Number.Integer:                'mi',
    Number.Integer.Long:           'il',
    Number.Oct:                    'mo',

    Operator:                      'o',
    Operator.Word:                 'ow',

    Punctuation:                   'p',
    Punctuation.Marker:            'pm',

    Comment:                       'c',
    Comment.Hashbang:              'ch',
    Comment.Multiline:             'cm',
    Comment.Preproc:               'cp',
    Comment.PreprocFile:           'cpf',
    Comment.Single:                'c1',
    Comment.Special:               'cs',

    Generic:                       'g',
    Generic.Deleted:               'gd',
    Generic.Emph:                  'ge',
    Generic.Error:                 'gr',
    Generic.Heading:               'gh',
    Generic.Inserted:              'gi',
    Generic.Output:                'go',
    Generic.Prompt:                'gp',
    Generic.Strong:                'gs',
    Generic.Subheading:            'gu',
    Generic.EmphStrong:            'ges',
    Generic.Traceback:             'gt',
}

# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.
"""
.. testsetup::

    from pip._vendor.packaging.specifiers import Specifier, SpecifierSet, InvalidSpecifier
    from pip._vendor.packaging.version import Version
"""

from __future__ import annotations

import abc
import itertools
import re
from typing import Callable, Iterable, Iterator, TypeVar, Union

from .utils import canonicalize_version
from .version import Version

UnparsedVersion = Union[Version, str]
UnparsedVersionVar = TypeVar("UnparsedVersionVar", bound=UnparsedVersion)
CallableOperator = Callable[[Version, str], bool]


def _coerce_version(version: UnparsedVersion) -> Version:
    if not isinstance(version, Version):
        version = Version(version)
    return version


class InvalidSpecifier(ValueError):
    """
    Raised when attempting to create a :class:`Specifier` with a specifier
    string that is invalid.

    >>> Specifier("lolwat")
    Traceback (most recent call last):
        ...
    packaging.specifiers.InvalidSpecifier: Invalid specifier: 'lolwat'
    """


class BaseSpecifier(metaclass=abc.ABCMeta):
    @abc.abstractmethod
    def __str__(self) -> str:
        """
        Returns the str representation of this Specifier-like object. This
        should be representative of the Specifier itself.
        """

    @abc.abstractmethod
    def __hash__(self) -> int:
        """
        Returns a hash value for this Specifier-like object.
        """

    @abc.abstractmethod
    def __eq__(self, other: object) -> bool:
        """
        Returns a boolean representing whether or not the two Specifier-like
        objects are equal.

        :param other: The other object to check against.
        """

    @property
    @abc.abstractmethod
    def prereleases(self) -> bool | None:
        """Whether or not pre-releases as a whole are allowed.

        This can be set to either ``True`` or ``False`` to explicitly enable or disable
        prereleases or it can be set to ``None`` (the default) to use default semantics.
        """

    @prereleases.setter
    def prereleases(self, value: bool) -> None:
        """Setter for :attr:`prereleases`.

        :param value: The value to set.
        """

    @abc.abstractmethod
    def contains(self, item: str, prereleases: bool | None = None) -> bool:
        """
        Determines if the given item is contained within this specifier.
        """

    @abc.abstractmethod
    def filter(
        self, iterable: Iterable[UnparsedVersionVar], prereleases: bool | None = None
    ) -> Iterator[UnparsedVersionVar]:
        """
        Takes an iterable of items and filters them so that only items which
        are contained within this specifier are allowed in it.
        """


class Specifier(BaseSpecifier):
    """This class abstracts handling of version specifiers.

    .. tip::

        It is generally not required to instantiate this manually. You should instead
        prefer to work with :class:`SpecifierSet` instead, which can parse
        comma-separated version specifiers (which is what package metadata contains).
    """

    _operator_regex_str = r"""
        (?P<operator>(~=|==|!=|<=|>=|<|>|===))
        """
    _version_regex_str = r"""
        (?P<version>
            (?:
                # The identity operators allow for an escape hatch that will
                # do an exact string match of the version you wish to install.
                # This will not be parsed by PEP 440 and we cannot determine
                # any semantic meaning from it. This operator is discouraged
                # but included entirely as an escape hatch.
                (?<====)  # Only match for the identity operator
                \s*
                [^\s;)]*  # The arbitrary version can be just about anything,
                          # we match everything except for whitespace, a
                          # semi-colon for marker support, and a closing paren
                          # since versions can be enclosed in them.
            )
            |
            (?:
                # The (non)equality operators allow for wild card and local
                # versions to be specified so we have to define these two
                # operators separately to enable that.
                (?<===|!=)            # Only match for equals and not equals

                \s*
                v?
                (?:[0-9]+!)?          # epoch
                [0-9]+(?:\.[0-9]+)*   # release

                # You cannot use a wild card and a pre-release, post-release, a dev or
                # local version together so group them with a | and make them optional.
                (?:
                    \.\*  # Wild card syntax of .*
                    |
                    (?:                                  # pre release
                        [-_\.]?
                        (alpha|beta|preview|pre|a|b|c|rc)
                        [-_\.]?
                        [0-9]*
                    )?
                    (?:                                  # post release
                        (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
                    )?
                    (?:[-_\.]?dev[-_\.]?[0-9]*)?         # dev release
                    (?:\+[a-z0-9]+(?:[-_\.][a-z0-9]+)*)? # local
                )?
            )
            |
            (?:
                # The compatible operator requires at least two digits in the
                # release segment.
                (?<=~=)               # Only match for the compatible operator

                \s*
                v?
                (?:[0-9]+!)?          # epoch
                [0-9]+(?:\.[0-9]+)+   # release  (We have a + instead of a *)
                (?:                   # pre release
                    [-_\.]?
                    (alpha|beta|preview|pre|a|b|c|rc)
                    [-_\.]?
                    [0-9]*
                )?
                (?:                                   # post release
                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
                )?
                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
            )
            |
            (?:
                # All other operators only allow a sub set of what the
                # (non)equality operators do. Specifically they do not allow
                # local versions to be specified nor do they allow the prefix
                # matching wild cards.
                (?<!==|!=|~=)         # We have special cases for these
                                      # operators so we want to make sure they
                                      # don't match here.

                \s*
                v?
                (?:[0-9]+!)?          # epoch
                [0-9]+(?:\.[0-9]+)*   # release
                (?:                   # pre release
                    [-_\.]?
                    (alpha|beta|preview|pre|a|b|c|rc)
                    [-_\.]?
                    [0-9]*
                )?
                (?:                                   # post release
                    (?:-[0-9]+)|(?:[-_\.]?(post|rev|r)[-_\.]?[0-9]*)
                )?
                (?:[-_\.]?dev[-_\.]?[0-9]*)?          # dev release
            )
        )
        """

    _regex = re.compile(
        r"^\s*" + _operator_regex_str + _version_regex_str + r"\s*$",
        re.VERBOSE | re.IGNORECASE,
    )

    _operators = {
        "~=": "compatible",
        "==": "equal",
        "!=": "not_equal",
        "<=": "less_than_equal",
        ">=": "greater_than_equal",
        "<": "less_than",
        ">": "greater_than",
        "===": "arbitrary",
    }

    def __init__(self, spec: str = "", prereleases: bool | None = None) -> None:
        """Initialize a Specifier instance.

        :param spec:
            The string representation of a specifier which will be parsed and
            normalized before use.
        :param prereleases:
            This tells the specifier if it should accept prerelease versions if
            applicable or not. The default of ``None`` will autodetect it from the
            given specifiers.
        :raises InvalidSpecifier:
            If the given specifier is invalid (i.e. bad syntax).
        """
        match = self._regex.search(spec)
        if not match:
            raise InvalidSpecifier(f"Invalid specifier: '{spec}'")

        self._spec: tuple[str, str] = (
            match.group("operator").strip(),
            match.group("version").strip(),
        )

        # Store whether or not this Specifier should accept prereleases
        self._prereleases = prereleases

    # https://github.com/python/mypy/pull/13475#pullrequestreview-1079784515
    @property  # type: ignore[override]
    def prereleases(self) -> bool:
        # If there is an explicit prereleases set for this, then we'll just
        # blindly use that.
        if self._prereleases is not None:
            return self._prereleases

        # Look at all of our specifiers and determine if they are inclusive
        # operators, and if they are if they are including an explicit
        # prerelease.
        operator, version = self._spec
        if operator in ["==", ">=", "<=", "~=", "==="]:
            # The == specifier can include a trailing .*, if it does we
            # want to remove before parsing.
            if operator == "==" and version.endswith(".*"):
                version = version[:-2]

            # Parse the version, and if it is a pre-release than this
            # specifier allows pre-releases.
            if Version(version).is_prerelease:
                return True

        return False

    @prereleases.setter
    def prereleases(self, value: bool) -> None:
        self._prereleases = value

    @property
    def operator(self) -> str:
        """The operator of this specifier.

        >>> Specifier("==1.2.3").operator
        '=='
        """
        return self._spec[0]

    @property
    def version(self) -> str:
        """The version of this specifier.

        >>> Specifier("==1.2.3").version
        '1.2.3'
        """
        return self._spec[1]

    def __repr__(self) -> str:
        """A representation of the Specifier that shows all internal state.

        >>> Specifier('>=1.0.0')
        <Specifier('>=1.0.0')>
        >>> Specifier('>=1.0.0', prereleases=False)
        <Specifier('>=1.0.0', prereleases=False)>
        >>> Specifier('>=1.0.0', prereleases=True)
        <Specifier('>=1.0.0', prereleases=True)>
        """
        pre = (
            f", prereleases={self.prereleases!r}"
            if self._prereleases is not None
            else ""
        )

        return f"<{self.__class__.__name__}({str(self)!r}{pre})>"

    def __str__(self) -> str:
        """A string representation of the Specifier that can be round-tripped.

        >>> str(Specifier('>=1.0.0'))
        '>=1.0.0'
        >>> str(Specifier('>=1.0.0', prereleases=False))
        '>=1.0.0'
        """
        return "{}{}".format(*self._spec)

    @property
    def _canonical_spec(self) -> tuple[str, str]:
        canonical_version = canonicalize_version(
            self._spec[1],
            strip_trailing_zero=(self._spec[0] != "~="),
        )
        return self._spec[0], canonical_version

    def __hash__(self) -> int:
        return hash(self._canonical_spec)

    def __eq__(self, other: object) -> bool:
        """Whether or not the two Specifier-like objects are equal.

        :param other: The other object to check against.

        The value of :attr:`prereleases` is ignored.

        >>> Specifier("==1.2.3") == Specifier("== 1.2.3.0")
        True
        >>> (Specifier("==1.2.3", prereleases=False) ==
        ...  Specifier("==1.2.3", prereleases=True))
        True
        >>> Specifier("==1.2.3") == "==1.2.3"
        True
        >>> Specifier("==1.2.3") == Specifier("==1.2.4")
        False
        >>> Specifier("==1.2.3") == Specifier("~=1.2.3")
        False
        """
        if isinstance(other, str):
            try:
                other = self.__class__(str(other))
            except InvalidSpecifier:
                return NotImplemented
        elif not isinstance(other, self.__class__):
            return NotImplemented

        return self._canonical_spec == other._canonical_spec

    def _get_operator(self, op: str) -> CallableOperator:
        operator_callable: CallableOperator = getattr(
            self, f"_compare_{self._operators[op]}"
        )
        return operator_callable

    def _compare_compatible(self, prospective: Version, spec: str) -> bool:
        # Compatible releases have an equivalent combination of >= and ==. That
        # is that ~=2.2 is equivalent to >=2.2,==2.*. This allows us to
        # implement this in terms of the other specifiers instead of
        # implementing it ourselves. The only thing we need to do is construct
        # the other specifiers.

        # We want everything but the last item in the version, but we want to
        # ignore suffix segments.
        prefix = _version_join(
            list(itertools.takewhile(_is_not_suffix, _version_split(spec)))[:-1]
        )

        # Add the prefix notation to the end of our string
        prefix += ".*"

        return self._get_operator(">=")(prospective, spec) and self._get_operator("==")(
            prospective, prefix
        )

    def _compare_equal(self, prospective: Version, spec: str) -> bool:
        # We need special logic to handle prefix matching
        if spec.endswith(".*"):
            # In the case of prefix matching we want to ignore local segment.
            normalized_prospective = canonicalize_version(
                prospective.public, strip_trailing_zero=False
            )
            # Get the normalized version string ignoring the trailing .*
            normalized_spec = canonicalize_version(spec[:-2], strip_trailing_zero=False)
            # Split the spec out by bangs and dots, and pretend that there is
            # an implicit dot in between a release segment and a pre-release segment.
            split_spec = _version_split(normalized_spec)

            # Split the prospective version out by bangs and dots, and pretend
            # that there is an implicit dot in between a release segment and
            # a pre-release segment.
            split_prospective = _version_split(normalized_prospective)

            # 0-pad the prospective version before shortening it to get the correct
            # shortened version.
            padded_prospective, _ = _pad_version(split_prospective, split_spec)

            # Shorten the prospective version to be the same length as the spec
            # so that we can determine if the specifier is a prefix of the
            # prospective version or not.
            shortened_prospective = padded_prospective[: len(split_spec)]

            return shortened_prospective == split_spec
        else:
            # Convert our spec string into a Version
            spec_version = Version(spec)

            # If the specifier does not have a local segment, then we want to
            # act as if the prospective version also does not have a local
            # segment.
            if not spec_version.local:
                prospective = Version(prospective.public)

            return prospective == spec_version

    def _compare_not_equal(self, prospective: Version, spec: str) -> bool:
        return not self._compare_equal(prospective, spec)

    def _compare_less_than_equal(self, prospective: Version, spec: str) -> bool:
        # NB: Local version identifiers are NOT permitted in the version
        # specifier, so local version labels can be universally removed from
        # the prospective version.
        return Version(prospective.public) <= Version(spec)

    def _compare_greater_than_equal(self, prospective: Version, spec: str) -> bool:
        # NB: Local version identifiers are NOT permitted in the version
        # specifier, so local version labels can be universally removed from
        # the prospective version.
        return Version(prospective.public) >= Version(spec)

    def _compare_less_than(self, prospective: Version, spec_str: str) -> bool:
        # Convert our spec to a Version instance, since we'll want to work with
        # it as a version.
        spec = Version(spec_str)

        # Check to see if the prospective version is less than the spec
        # version. If it's not we can short circuit and just return False now
        # instead of doing extra unneeded work.
        if not prospective < spec:
            return False

        # This special case is here so that, unless the specifier itself
        # includes is a pre-release version, that we do not accept pre-release
        # versions for the version mentioned in the specifier (e.g. <3.1 should
        # not match 3.1.dev0, but should match 3.0.dev0).
        if not spec.is_prerelease and prospective.is_prerelease:
            if Version(prospective.base_version) == Version(spec.base_version):
                return False

        # If we've gotten to here, it means that prospective version is both
        # less than the spec version *and* it's not a pre-release of the same
        # version in the spec.
        return True

    def _compare_greater_than(self, prospective: Version, spec_str: str) -> bool:
        # Convert our spec to a Version instance, since we'll want to work with
        # it as a version.
        spec = Version(spec_str)

        # Check to see if the prospective version is greater than the spec
        # version. If it's not we can short circuit and just return False now
        # instead of doing extra unneeded work.
        if not prospective > spec:
            return False

        # This special case is here so that, unless the specifier itself
        # includes is a post-release version, that we do not accept
        # post-release versions for the version mentioned in the specifier
        # (e.g. >3.1 should not match 3.0.post0, but should match 3.2.post0).
        if not spec.is_postrelease and prospective.is_postrelease:
            if Version(prospective.base_version) == Version(spec.base_version):
                return False

        # Ensure that we do not allow a local version of the version mentioned
        # in the specifier, which is technically greater than, to match.
        if prospective.local is not None:
            if Version(prospective.base_version) == Version(spec.base_version):
                return False

        # If we've gotten to here, it means that prospective version is both
        # greater than the spec version *and* it's not a pre-release of the
        # same version in the spec.
        return True

    def _compare_arbitrary(self, prospective: Version, spec: str) -> bool:
        return str(prospective).lower() == str(spec).lower()

    def __contains__(self, item: str | Version) -> bool:
        """Return whether or not the item is contained in this specifier.

        :param item: The item to check for.

        This is used for the ``in`` operator and behaves the same as
        :meth:`contains` with no ``prereleases`` argument passed.

        >>> "1.2.3" in Specifier(">=1.2.3")
        True
        >>> Version("1.2.3") in Specifier(">=1.2.3")
        True
        >>> "1.0.0" in Specifier(">=1.2.3")
        False
        >>> "1.3.0a1" in Specifier(">=1.2.3")
        False
        >>> "1.3.0a1" in Specifier(">=1.2.3", prereleases=True)
        True
        """
        return self.contains(item)

    def contains(self, item: UnparsedVersion, prereleases: bool | None = None) -> bool:
        """Return whether or not the item is contained in this specifier.

        :param item:
            The item to check for, which can be a version string or a
            :class:`Version` instance.
        :param prereleases:
            Whether or not to match prereleases with this Specifier. If set to
            ``None`` (the default), it uses :attr:`prereleases` to determine
            whether or not prereleases are allowed.

        >>> Specifier(">=1.2.3").contains("1.2.3")
        True
        >>> Specifier(">=1.2.3").contains(Version("1.2.3"))
        True
        >>> Specifier(">=1.2.3").contains("1.0.0")
        False
        >>> Specifier(">=1.2.3").contains("1.3.0a1")
        False
        >>> Specifier(">=1.2.3", prereleases=True).contains("1.3.0a1")
        True
        >>> Specifier(">=1.2.3").contains("1.3.0a1", prereleases=True)
        True
        """

        # Determine if prereleases are to be allowed or not.
        if prereleases is None:
            prereleases = self.prereleases

        # Normalize item to a Version, this allows us to have a shortcut for
        # "2.0" in Specifier(">=2")
        normalized_item = _coerce_version(item)

        # Determine if we should be supporting prereleases in this specifier
        # or not, if we do not support prereleases than we can short circuit
        # logic if this version is a prereleases.
        if normalized_item.is_prerelease and not prereleases:
            return False

        # Actually do the comparison to determine if this item is contained
        # within this Specifier or not.
        operator_callable: CallableOperator = self._get_operator(self.operator)
        return operator_callable(normalized_item, self.version)

    def filter(
        self, iterable: Iterable[UnparsedVersionVar], prereleases: bool | None = None
    ) -> Iterator[UnparsedVersionVar]:
        """Filter items in the given iterable, that match the specifier.

        :param iterable:
            An iterable that can contain version strings and :class:`Version` instances.
            The items in the iterable will be filtered according to the specifier.
        :param prereleases:
            Whether or not to allow prereleases in the returned iterator. If set to
            ``None`` (the default), it will be intelligently decide whether to allow
            prereleases or not (based on the :attr:`prereleases` attribute, and
            whether the only versions matching are prereleases).

        This method is smarter than just ``filter(Specifier().contains, [...])``
        because it implements the rule from :pep:`440` that a prerelease item
        SHOULD be accepted if no other versions match the given specifier.

        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.3", "1.5a1"]))
        ['1.3']
        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.2.3", "1.3", Version("1.4")]))
        ['1.2.3', '1.3', <Version('1.4')>]
        >>> list(Specifier(">=1.2.3").filter(["1.2", "1.5a1"]))
        ['1.5a1']
        >>> list(Specifier(">=1.2.3").filter(["1.3", "1.5a1"], prereleases=True))
        ['1.3', '1.5a1']
        >>> list(Specifier(">=1.2.3", prereleases=True).filter(["1.3", "1.5a1"]))
        ['1.3', '1.5a1']
        """

        yielded = False
        found_prereleases = []

        kw = {"prereleases": prereleases if prereleases is not None else True}

        # Attempt to iterate over all the values in the iterable and if any of
        # them match, yield them.
        for version in iterable:
            parsed_version = _coerce_version(version)

            if self.contains(parsed_version, **kw):
                # If our version is a prerelease, and we were not set to allow
                # prereleases, then we'll store it for later in case nothing
                # else matches this specifier.
                if parsed_version.is_prerelease and not (
                    prereleases or self.prereleases
                ):
                    found_prereleases.append(version)
                # Either this is not a prerelease, or we should have been
                # accepting prereleases from the beginning.
                else:
                    yielded = True
                    yield version

        # Now that we've iterated over everything, determine if we've yielded
        # any values, and if we have not and we have any prereleases stored up
        # then we will go ahead and yield the prereleases.
        if not yielded and found_prereleases:
            for version in found_prereleases:
                yield version


_prefix_regex = re.compile(r"^([0-9]+)((?:a|b|c|rc)[0-9]+)$")


def _version_split(version: str) -> list[str]:
    """Split version into components.

    The split components are intended for version comparison. The logic does
    not attempt to retain the original version string, so joining the
    components back with :func:`_version_join` may not produce the original
    version string.
    """
    result: list[str] = []

    epoch, _, rest = version.rpartition("!")
    result.append(epoch or "0")

    for item in rest.split("."):
        match = _prefix_regex.search(item)
        if match:
            result.extend(match.groups())
        else:
            result.append(item)
    return result


def _version_join(components: list[str]) -> str:
    """Join split version components into a version string.

    This function assumes the input came from :func:`_version_split`, where the
    first component must be the epoch (either empty or numeric), and all other
    components numeric.
    """
    epoch, *rest = components
    return f"{epoch}!{'.'.join(rest)}"


def _is_not_suffix(segment: str) -> bool:
    return not any(
        segment.startswith(prefix) for prefix in ("dev", "a", "b", "rc", "post")
    )


def _pad_version(left: list[str], right: list[str]) -> tuple[list[str], list[str]]:
    left_split, right_split = [], []

    # Get the release segment of our versions
    left_split.append(list(itertools.takewhile(lambda x: x.isdigit(), left)))
    right_split.append(list(itertools.takewhile(lambda x: x.isdigit(), right)))

    # Get the rest of our versions
    left_split.append(left[len(left_split[0]) :])
    right_split.append(right[len(right_split[0]) :])

    # Insert our padding
    left_split.insert(1, ["0"] * max(0, len(right_split[0]) - len(left_split[0])))
    right_split.insert(1, ["0"] * max(0, len(left_split[0]) - len(right_split[0])))

    return (
        list(itertools.chain.from_iterable(left_split)),
        list(itertools.chain.from_iterable(right_split)),
    )


class SpecifierSet(BaseSpecifier):
    """This class abstracts handling of a set of version specifiers.

    It can be passed a single specifier (``>=3.0``), a comma-separated list of
    specifiers (``>=3.0,!=3.1``), or no specifier at all.
    """

    def __init__(self, specifiers: str = "", prereleases: bool | None = None) -> None:
        """Initialize a SpecifierSet instance.

        :param specifiers:
            The string representation of a specifier or a comma-separated list of
            specifiers which will be parsed and normalized before use.
        :param prereleases:
            This tells the SpecifierSet if it should accept prerelease versions if
            applicable or not. The default of ``None`` will autodetect it from the
            given specifiers.

        :raises InvalidSpecifier:
            If the given ``specifiers`` are not parseable than this exception will be
            raised.
        """

        # Split on `,` to break each individual specifier into it's own item, and
        # strip each item to remove leading/trailing whitespace.
        split_specifiers = [s.strip() for s in specifiers.split(",") if s.strip()]

        # Make each individual specifier a Specifier and save in a frozen set for later.
        self._specs = frozenset(map(Specifier, split_specifiers))

        # Store our prereleases value so we can use it later to determine if
        # we accept prereleases or not.
        self._prereleases = prereleases

    @property
    def prereleases(self) -> bool | None:
        # If we have been given an explicit prerelease modifier, then we'll
        # pass that through here.
        if self._prereleases is not None:
            return self._prereleases

        # If we don't have any specifiers, and we don't have a forced value,
        # then we'll just return None since we don't know if this should have
        # pre-releases or not.
        if not self._specs:
            return None

        # Otherwise we'll see if any of the given specifiers accept
        # prereleases, if any of them do we'll return True, otherwise False.
        return any(s.prereleases for s in self._specs)

    @prereleases.setter
    def prereleases(self, value: bool) -> None:
        self._prereleases = value

    def __repr__(self) -> str:
        """A representation of the specifier set that shows all internal state.

        Note that the ordering of the individual specifiers within the set may not
        match the input string.

        >>> SpecifierSet('>=1.0.0,!=2.0.0')
        <SpecifierSet('!=2.0.0,>=1.0.0')>
        >>> SpecifierSet('>=1.0.0,!=2.0.0', prereleases=False)
        <SpecifierSet('!=2.0.0,>=1.0.0', prereleases=False)>
        >>> SpecifierSet('>=1.0.0,!=2.0.0', prereleases=True)
        <SpecifierSet('!=2.0.0,>=1.0.0', prereleases=True)>
        """
        pre = (
            f", prereleases={self.prereleases!r}"
            if self._prereleases is not None
            else ""
        )

        return f"<SpecifierSet({str(self)!r}{pre})>"

    def __str__(self) -> str:
        """A string representation of the specifier set that can be round-tripped.

        Note that the ordering of the individual specifiers within the set may not
        match the input string.

        >>> str(SpecifierSet(">=1.0.0,!=1.0.1"))
        '!=1.0.1,>=1.0.0'
        >>> str(SpecifierSet(">=1.0.0,!=1.0.1", prereleases=False))
        '!=1.0.1,>=1.0.0'
        """
        return ",".join(sorted(str(s) for s in self._specs))

    def __hash__(self) -> int:
        return hash(self._specs)

    def __and__(self, other: SpecifierSet | str) -> SpecifierSet:
        """Return a SpecifierSet which is a combination of the two sets.

        :param other: The other object to combine with.

        >>> SpecifierSet(">=1.0.0,!=1.0.1") & '<=2.0.0,!=2.0.1'
        <SpecifierSet('!=1.0.1,!=2.0.1,<=2.0.0,>=1.0.0')>
        >>> SpecifierSet(">=1.0.0,!=1.0.1") & SpecifierSet('<=2.0.0,!=2.0.1')
        <SpecifierSet('!=1.0.1,!=2.0.1,<=2.0.0,>=1.0.0')>
        """
        if isinstance(other, str):
            other = SpecifierSet(other)
        elif not isinstance(other, SpecifierSet):
            return NotImplemented

        specifier = SpecifierSet()
        specifier._specs = frozenset(self._specs | other._specs)

        if self._prereleases is None and other._prereleases is not None:
            specifier._prereleases = other._prereleases
        elif self._prereleases is not None and other._prereleases is None:
            specifier._prereleases = self._prereleases
        elif self._prereleases == other._prereleases:
            specifier._prereleases = self._prereleases
        else:
            raise ValueError(
                "Cannot combine SpecifierSets with True and False prerelease "
                "overrides."
            )

        return specifier

    def __eq__(self, other: object) -> bool:
        """Whether or not the two SpecifierSet-like objects are equal.

        :param other: The other object to check against.

        The value of :attr:`prereleases` is ignored.

        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0,!=1.0.1")
        True
        >>> (SpecifierSet(">=1.0.0,!=1.0.1", prereleases=False) ==
        ...  SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True))
        True
        >>> SpecifierSet(">=1.0.0,!=1.0.1") == ">=1.0.0,!=1.0.1"
        True
        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0")
        False
        >>> SpecifierSet(">=1.0.0,!=1.0.1") == SpecifierSet(">=1.0.0,!=1.0.2")
        False
        """
        if isinstance(other, (str, Specifier)):
            other = SpecifierSet(str(other))
        elif not isinstance(other, SpecifierSet):
            return NotImplemented

        return self._specs == other._specs

    def __len__(self) -> int:
        """Returns the number of specifiers in this specifier set."""
        return len(self._specs)

    def __iter__(self) -> Iterator[Specifier]:
        """
        Returns an iterator over all the underlying :class:`Specifier` instances
        in this specifier set.

        >>> sorted(SpecifierSet(">=1.0.0,!=1.0.1"), key=str)
        [<Specifier('!=1.0.1')>, <Specifier('>=1.0.0')>]
        """
        return iter(self._specs)

    def __contains__(self, item: UnparsedVersion) -> bool:
        """Return whether or not the item is contained in this specifier.

        :param item: The item to check for.

        This is used for the ``in`` operator and behaves the same as
        :meth:`contains` with no ``prereleases`` argument passed.

        >>> "1.2.3" in SpecifierSet(">=1.0.0,!=1.0.1")
        True
        >>> Version("1.2.3") in SpecifierSet(">=1.0.0,!=1.0.1")
        True
        >>> "1.0.1" in SpecifierSet(">=1.0.0,!=1.0.1")
        False
        >>> "1.3.0a1" in SpecifierSet(">=1.0.0,!=1.0.1")
        False
        >>> "1.3.0a1" in SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True)
        True
        """
        return self.contains(item)

    def contains(
        self,
        item: UnparsedVersion,
        prereleases: bool | None = None,
        installed: bool | None = None,
    ) -> bool:
        """Return whether or not the item is contained in this SpecifierSet.

        :param item:
            The item to check for, which can be a version string or a
            :class:`Version` instance.
        :param prereleases:
            Whether or not to match prereleases with this SpecifierSet. If set to
            ``None`` (the default), it uses :attr:`prereleases` to determine
            whether or not prereleases are allowed.

        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.2.3")
        True
        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains(Version("1.2.3"))
        True
        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.0.1")
        False
        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.3.0a1")
        False
        >>> SpecifierSet(">=1.0.0,!=1.0.1", prereleases=True).contains("1.3.0a1")
        True
        >>> SpecifierSet(">=1.0.0,!=1.0.1").contains("1.3.0a1", prereleases=True)
        True
        """
        # Ensure that our item is a Version instance.
        if not isinstance(item, Version):
            item = Version(item)

        # Determine if we're forcing a prerelease or not, if we're not forcing
        # one for this particular filter call, then we'll use whatever the
        # SpecifierSet thinks for whether or not we should support prereleases.
        if prereleases is None:
            prereleases = self.prereleases

        # We can determine if we're going to allow pre-releases by looking to
        # see if any of the underlying items supports them. If none of them do
        # and this item is a pre-release then we do not allow it and we can
        # short circuit that here.
        # Note: This means that 1.0.dev1 would not be contained in something
        #       like >=1.0.devabc however it would be in >=1.0.debabc,>0.0.dev0
        if not prereleases and item.is_prerelease:
            return False

        if installed and item.is_prerelease:
            item = Version(item.base_version)

        # We simply dispatch to the underlying specs here to make sure that the
        # given version is contained within all of them.
        # Note: This use of all() here means that an empty set of specifiers
        #       will always return True, this is an explicit design decision.
        return all(s.contains(item, prereleases=prereleases) for s in self._specs)

    def filter(
        self, iterable: Iterable[UnparsedVersionVar], prereleases: bool | None = None
    ) -> Iterator[UnparsedVersionVar]:
        """Filter items in the given iterable, that match the specifiers in this set.

        :param iterable:
            An iterable that can contain version strings and :class:`Version` instances.
            The items in the iterable will be filtered according to the specifier.
        :param prereleases:
            Whether or not to allow prereleases in the returned iterator. If set to
            ``None`` (the default), it will be intelligently decide whether to allow
            prereleases or not (based on the :attr:`prereleases` attribute, and
            whether the only versions matching are prereleases).

        This method is smarter than just ``filter(SpecifierSet(...).contains, [...])``
        because it implements the rule from :pep:`440` that a prerelease item
        SHOULD be accepted if no other versions match the given specifier.

        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.3", "1.5a1"]))
        ['1.3']
        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.3", Version("1.4")]))
        ['1.3', <Version('1.4')>]
        >>> list(SpecifierSet(">=1.2.3").filter(["1.2", "1.5a1"]))
        []
        >>> list(SpecifierSet(">=1.2.3").filter(["1.3", "1.5a1"], prereleases=True))
        ['1.3', '1.5a1']
        >>> list(SpecifierSet(">=1.2.3", prereleases=True).filter(["1.3", "1.5a1"]))
        ['1.3', '1.5a1']

        An "empty" SpecifierSet will filter items based on the presence of prerelease
        versions in the set.

        >>> list(SpecifierSet("").filter(["1.3", "1.5a1"]))
        ['1.3']
        >>> list(SpecifierSet("").filter(["1.5a1"]))
        ['1.5a1']
        >>> list(SpecifierSet("", prereleases=True).filter(["1.3", "1.5a1"]))
        ['1.3', '1.5a1']
        >>> list(SpecifierSet("").filter(["1.3", "1.5a1"], prereleases=True))
        ['1.3', '1.5a1']
        """
        # Determine if we're forcing a prerelease or not, if we're not forcing
        # one for this particular filter call, then we'll use whatever the
        # SpecifierSet thinks for whether or not we should support prereleases.
        if prereleases is None:
            prereleases = self.prereleases

        # If we have any specifiers, then we want to wrap our iterable in the
        # filter method for each one, this will act as a logical AND amongst
        # each specifier.
        if self._specs:
            for spec in self._specs:
                iterable = spec.filter(iterable, prereleases=bool(prereleases))
            return iter(iterable)
        # If we do not have any specifiers, then we need to have a rough filter
        # which will filter out any pre-releases, unless there are no final
        # releases.
        else:
            filtered: list[UnparsedVersionVar] = []
            found_prereleases: list[UnparsedVersionVar] = []

            for item in iterable:
                parsed_version = _coerce_version(item)

                # Store any item which is a pre-release for later unless we've
                # already found a final version or we are accepting prereleases
                if parsed_version.is_prerelease and not prereleases:
                    if not filtered:
                        found_prereleases.append(item)
                else:
                    filtered.append(item)

            # If we've found no items except for pre-releases, then we'll go
            # ahead and use the pre-releases
            if not filtered and found_prereleases and prereleases is None:
                return iter(found_prereleases)

            return iter(filtered)