third_party/jinja2/utils.py - cobalt - Git at Google

 import enum
 import json
 import os
 import re
 import typing as t
 from collections import abc
 from collections import deque
 from random import choice
 from random import randrange
 from threading import Lock
 from types import CodeType
 from urllib.parse import quote_from_bytes

 import markupsafe

 if t.TYPE_CHECKING:
     import typing_extensions as te

 F = t.TypeVar("F", bound=t.Callable[..., t.Any])

 # special singleton representing missing values for the runtime
 missing: t.Any = type("MissingType", (), {"__repr__": lambda x: "missing"})()

 internal_code: t.MutableSet[CodeType] = set()

 concat = "".join


 def pass_context(f: F) -> F:
     """Pass the :class:`~jinja2.runtime.Context` as the first argument
     to the decorated function when called while rendering a template.

     Can be used on functions, filters, and tests.

     If only ``Context.eval_context`` is needed, use
     :func:`pass_eval_context`. If only ``Context.environment`` is
     needed, use :func:`pass_environment`.

     .. versionadded:: 3.0.0
         Replaces ``contextfunction`` and ``contextfilter``.
     """
     f.jinja_pass_arg = _PassArg.context  # type: ignore
     return f


 def pass_eval_context(f: F) -> F:
     """Pass the :class:`~jinja2.nodes.EvalContext` as the first argument
     to the decorated function when called while rendering a template.
     See :ref:`eval-context`.

     Can be used on functions, filters, and tests.

     If only ``EvalContext.environment`` is needed, use
     :func:`pass_environment`.

     .. versionadded:: 3.0.0
         Replaces ``evalcontextfunction`` and ``evalcontextfilter``.
     """
     f.jinja_pass_arg = _PassArg.eval_context  # type: ignore
     return f


 def pass_environment(f: F) -> F:
     """Pass the :class:`~jinja2.Environment` as the first argument to
     the decorated function when called while rendering a template.

     Can be used on functions, filters, and tests.

     .. versionadded:: 3.0.0
         Replaces ``environmentfunction`` and ``environmentfilter``.
     """
     f.jinja_pass_arg = _PassArg.environment  # type: ignore
     return f


 class _PassArg(enum.Enum):
     context = enum.auto()
     eval_context = enum.auto()
     environment = enum.auto()

     @classmethod
     def from_obj(cls, obj: F) -> t.Optional["_PassArg"]:
         if hasattr(obj, "jinja_pass_arg"):
             return obj.jinja_pass_arg  # type: ignore

         return None


 def internalcode(f: F) -> F:
     """Marks the function as internally used"""
     internal_code.add(f.__code__)
     return f


 def is_undefined(obj: t.Any) -> bool:
     """Check if the object passed is undefined.  This does nothing more than
     performing an instance check against :class:`Undefined` but looks nicer.
     This can be used for custom filters or tests that want to react to
     undefined variables.  For example a custom default filter can look like
     this::

         def default(var, default=''):
             if is_undefined(var):
                 return default
             return var
     """
     from .runtime import Undefined

     return isinstance(obj, Undefined)


 def consume(iterable: t.Iterable[t.Any]) -> None:
     """Consumes an iterable without doing anything with it."""
     for _ in iterable:
         pass


 def clear_caches() -> None:
     """Jinja keeps internal caches for environments and lexers.  These are
     used so that Jinja doesn't have to recreate environments and lexers all
     the time.  Normally you don't have to care about that but if you are
     measuring memory consumption you may want to clean the caches.
     """
     from .environment import get_spontaneous_environment
     from .lexer import _lexer_cache

     get_spontaneous_environment.cache_clear()
     _lexer_cache.clear()


 def import_string(import_name: str, silent: bool = False) -> t.Any:
     """Imports an object based on a string.  This is useful if you want to
     use import paths as endpoints or something similar.  An import path can
     be specified either in dotted notation (``xml.sax.saxutils.escape``)
     or with a colon as object delimiter (``xml.sax.saxutils:escape``).

     If the `silent` is True the return value will be `None` if the import
     fails.

     :return: imported object
     """
     try:
         if ":" in import_name:
             module, obj = import_name.split(":", 1)
         elif "." in import_name:
             module, _, obj = import_name.rpartition(".")
         else:
             return __import__(import_name)
         return getattr(__import__(module, None, None, [obj]), obj)
     except (ImportError, AttributeError):
         if not silent:
             raise


 def open_if_exists(filename: str, mode: str = "rb") -> t.Optional[t.IO]:
     """Returns a file descriptor for the filename if that file exists,
     otherwise ``None``.
     """
     if not os.path.isfile(filename):
         return None

     return open(filename, mode)


 def object_type_repr(obj: t.Any) -> str:
     """Returns the name of the object's type.  For some recognized
     singletons the name of the object is returned instead. (For
     example for `None` and `Ellipsis`).
     """
     if obj is None:
         return "None"
     elif obj is Ellipsis:
         return "Ellipsis"

     cls = type(obj)

     if cls.__module__ == "builtins":
         return f"{cls.__name__} object"

     return f"{cls.__module__}.{cls.__name__} object"


 def pformat(obj: t.Any) -> str:
     """Format an object using :func:`pprint.pformat`."""
     from pprint import pformat  # type: ignore

     return pformat(obj)


 _http_re = re.compile(
     r"""
     ^
     (
         (https?://|www\.)  # scheme or www
         (([\w%-]+\.)+)?  # subdomain
         (
             [a-z]{2,63}  # basic tld
         |
             xn--[\w%]{2,59}  # idna tld
         )
     |
         ([\w%-]{2,63}\.)+  # basic domain
         (com|net|int|edu|gov|org|info|mil)  # basic tld
     |
         (https?://)  # scheme
         (
             (([\d]{1,3})(\.[\d]{1,3}){3})  # IPv4
         |
             (\[([\da-f]{0,4}:){2}([\da-f]{0,4}:?){1,6}])  # IPv6
         )
     )
     (?::[\d]{1,5})?  # port
     (?:[/?#]\S*)?  # path, query, and fragment
     $
     """,
     re.IGNORECASE | re.VERBOSE,
 )
 _email_re = re.compile(r"^\S+@\w[\w.-]*\.\w+$")


 def urlize(
     text: str,
     trim_url_limit: t.Optional[int] = None,
     rel: t.Optional[str] = None,
     target: t.Optional[str] = None,
     extra_schemes: t.Optional[t.Iterable[str]] = None,
 ) -> str:
     """Convert URLs in text into clickable links.

     This may not recognize links in some situations. Usually, a more
     comprehensive formatter, such as a Markdown library, is a better
     choice.

     Works on ``http://``, ``https://``, ``www.``, ``mailto:``, and email
     addresses. Links with trailing punctuation (periods, commas, closing
     parentheses) and leading punctuation (opening parentheses) are
     recognized excluding the punctuation. Email addresses that include
     header fields are not recognized (for example,
     ``mailto:address@example.com?cc=copy@example.com``).

     :param text: Original text containing URLs to link.
     :param trim_url_limit: Shorten displayed URL values to this length.
     :param target: Add the ``target`` attribute to links.
     :param rel: Add the ``rel`` attribute to links.
     :param extra_schemes: Recognize URLs that start with these schemes
         in addition to the default behavior.

     .. versionchanged:: 3.0
         The ``extra_schemes`` parameter was added.

     .. versionchanged:: 3.0
         Generate ``https://`` links for URLs without a scheme.

     .. versionchanged:: 3.0
         The parsing rules were updated. Recognize email addresses with
         or without the ``mailto:`` scheme. Validate IP addresses. Ignore
         parentheses and brackets in more cases.
     """
     if trim_url_limit is not None:

         def trim_url(x: str) -> str:
             if len(x) > trim_url_limit:  # type: ignore
                 return f"{x[:trim_url_limit]}..."

             return x

     else:

         def trim_url(x: str) -> str:
             return x

     words = re.split(r"(\s+)", str(markupsafe.escape(text)))
     rel_attr = f' rel="{markupsafe.escape(rel)}"' if rel else ""
     target_attr = f' target="{markupsafe.escape(target)}"' if target else ""

     for i, word in enumerate(words):
         head, middle, tail = "", word, ""
         match = re.match(r"^([(<]|&lt;)+", middle)

         if match:
             head = match.group()
             middle = middle[match.end() :]

         # Unlike lead, which is anchored to the start of the string,
         # need to check that the string ends with any of the characters
         # before trying to match all of them, to avoid backtracking.
         if middle.endswith((")", ">", ".", ",", "\n", "&gt;")):
             match = re.search(r"([)>.,\n]|&gt;)+$", middle)

             if match:
                 tail = match.group()
                 middle = middle[: match.start()]

         # Prefer balancing parentheses in URLs instead of ignoring a
         # trailing character.
         for start_char, end_char in ("(", ")"), ("<", ">"), ("&lt;", "&gt;"):
             start_count = middle.count(start_char)

             if start_count <= middle.count(end_char):
                 # Balanced, or lighter on the left
                 continue

             # Move as many as possible from the tail to balance
             for _ in range(min(start_count, tail.count(end_char))):
                 end_index = tail.index(end_char) + len(end_char)
                 # Move anything in the tail before the end char too
                 middle += tail[:end_index]
                 tail = tail[end_index:]

         if _http_re.match(middle):
             if middle.startswith("https://") or middle.startswith("http://"):
                 middle = (
                     f'<a href="{middle}"{rel_attr}{target_attr}>{trim_url(middle)}</a>'
                 )
             else:
                 middle = (
                     f'<a href="https://{middle}"{rel_attr}{target_attr}>'
                     f"{trim_url(middle)}</a>"
                 )

         elif middle.startswith("mailto:") and _email_re.match(middle[7:]):
             middle = f'<a href="{middle}">{middle[7:]}</a>'

         elif (
             "@" in middle
             and not middle.startswith("www.")
             and ":" not in middle
             and _email_re.match(middle)
         ):
             middle = f'<a href="mailto:{middle}">{middle}</a>'

         elif extra_schemes is not None:
             for scheme in extra_schemes:
                 if middle != scheme and middle.startswith(scheme):
                     middle = f'<a href="{middle}"{rel_attr}{target_attr}>{middle}</a>'

         words[i] = f"{head}{middle}{tail}"

     return "".join(words)


 def generate_lorem_ipsum(
     n: int = 5, html: bool = True, min: int = 20, max: int = 100
 ) -> str:
     """Generate some lorem ipsum for the template."""
     from .constants import LOREM_IPSUM_WORDS

     words = LOREM_IPSUM_WORDS.split()
     result = []

     for _ in range(n):
         next_capitalized = True
         last_comma = last_fullstop = 0
         word = None
         last = None
         p = []

         # each paragraph contains out of 20 to 100 words.
         for idx, _ in enumerate(range(randrange(min, max))):
             while True:
                 word = choice(words)
                 if word != last:
                     last = word
                     break
             if next_capitalized:
                 word = word.capitalize()
                 next_capitalized = False
             # add commas
             if idx - randrange(3, 8) > last_comma:
                 last_comma = idx
                 last_fullstop += 2
                 word += ","
             # add end of sentences
             if idx - randrange(10, 20) > last_fullstop:
                 last_comma = last_fullstop = idx
                 word += "."
                 next_capitalized = True
             p.append(word)

         # ensure that the paragraph ends with a dot.
         p_str = " ".join(p)

         if p_str.endswith(","):
             p_str = p_str[:-1] + "."
         elif not p_str.endswith("."):
             p_str += "."

         result.append(p_str)

     if not html:
         return "\n\n".join(result)
     return markupsafe.Markup(
         "\n".join(f"<p>{markupsafe.escape(x)}</p>" for x in result)
     )


 def url_quote(obj: t.Any, charset: str = "utf-8", for_qs: bool = False) -> str:
     """Quote a string for use in a URL using the given charset.

     :param obj: String or bytes to quote. Other types are converted to
         string then encoded to bytes using the given charset.
     :param charset: Encode text to bytes using this charset.
     :param for_qs: Quote "/" and use "+" for spaces.
     """
     if not isinstance(obj, bytes):
         if not isinstance(obj, str):
             obj = str(obj)

         obj = obj.encode(charset)

     safe = b"" if for_qs else b"/"
     rv = quote_from_bytes(obj, safe)

     if for_qs:
         rv = rv.replace("%20", "+")

     return rv


 @abc.MutableMapping.register
 class LRUCache:
     """A simple LRU Cache implementation."""

     # this is fast for small capacities (something below 1000) but doesn't
     # scale.  But as long as it's only used as storage for templates this
     # won't do any harm.

     def __init__(self, capacity: int) -> None:
         self.capacity = capacity
         self._mapping: t.Dict[t.Any, t.Any] = {}
         self._queue: "te.Deque[t.Any]" = deque()
         self._postinit()

     def _postinit(self) -> None:
         # alias all queue methods for faster lookup
         self._popleft = self._queue.popleft
         self._pop = self._queue.pop
         self._remove = self._queue.remove
         self._wlock = Lock()
         self._append = self._queue.append

     def __getstate__(self) -> t.Mapping[str, t.Any]:
         return {
             "capacity": self.capacity,
             "_mapping": self._mapping,
             "_queue": self._queue,
         }

     def __setstate__(self, d: t.Mapping[str, t.Any]) -> None:
         self.__dict__.update(d)
         self._postinit()

     def __getnewargs__(self) -> t.Tuple:
         return (self.capacity,)

     def copy(self) -> "LRUCache":
         """Return a shallow copy of the instance."""
         rv = self.__class__(self.capacity)
         rv._mapping.update(self._mapping)
         rv._queue.extend(self._queue)
         return rv

     def get(self, key: t.Any, default: t.Any = None) -> t.Any:
         """Return an item from the cache dict or `default`"""
         try:
             return self[key]
         except KeyError:
             return default

     def setdefault(self, key: t.Any, default: t.Any = None) -> t.Any:
         """Set `default` if the key is not in the cache otherwise
         leave unchanged. Return the value of this key.
         """
         try:
             return self[key]
         except KeyError:
             self[key] = default
             return default

     def clear(self) -> None:
         """Clear the cache."""
         with self._wlock:
             self._mapping.clear()
             self._queue.clear()

     def __contains__(self, key: t.Any) -> bool:
         """Check if a key exists in this cache."""
         return key in self._mapping

     def __len__(self) -> int:
         """Return the current size of the cache."""
         return len(self._mapping)

     def __repr__(self) -> str:
         return f"<{type(self).__name__} {self._mapping!r}>"

     def __getitem__(self, key: t.Any) -> t.Any:
         """Get an item from the cache. Moves the item up so that it has the
         highest priority then.

         Raise a `KeyError` if it does not exist.
         """
         with self._wlock:
             rv = self._mapping[key]

             if self._queue[-1] != key:
                 try:
                     self._remove(key)
                 except ValueError:
                     # if something removed the key from the container
                     # when we read, ignore the ValueError that we would
                     # get otherwise.
                     pass

                 self._append(key)

             return rv

     def __setitem__(self, key: t.Any, value: t.Any) -> None:
         """Sets the value for an item. Moves the item up so that it
         has the highest priority then.
         """
         with self._wlock:
             if key in self._mapping:
                 self._remove(key)
             elif len(self._mapping) == self.capacity:
                 del self._mapping[self._popleft()]

             self._append(key)
             self._mapping[key] = value

     def __delitem__(self, key: t.Any) -> None:
         """Remove an item from the cache dict.
         Raise a `KeyError` if it does not exist.
         """
         with self._wlock:
             del self._mapping[key]

             try:
                 self._remove(key)
             except ValueError:
                 pass

     def items(self) -> t.Iterable[t.Tuple[t.Any, t.Any]]:
         """Return a list of items."""
         result = [(key, self._mapping[key]) for key in list(self._queue)]
         result.reverse()
         return result

     def values(self) -> t.Iterable[t.Any]:
         """Return a list of all values."""
         return [x[1] for x in self.items()]

     def keys(self) -> t.Iterable[t.Any]:
         """Return a list of all keys ordered by most recent usage."""
         return list(self)

     def __iter__(self) -> t.Iterator[t.Any]:
         return reversed(tuple(self._queue))

     def __reversed__(self) -> t.Iterator[t.Any]:
         """Iterate over the keys in the cache dict, oldest items
         coming first.
         """
         return iter(tuple(self._queue))

     __copy__ = copy


 def select_autoescape(
     enabled_extensions: t.Collection[str] = ("html", "htm", "xml"),
     disabled_extensions: t.Collection[str] = (),
     default_for_string: bool = True,
     default: bool = False,
 ) -> t.Callable[[t.Optional[str]], bool]:
     """Intelligently sets the initial value of autoescaping based on the
     filename of the template.  This is the recommended way to configure
     autoescaping if you do not want to write a custom function yourself.

     If you want to enable it for all templates created from strings or
     for all templates with `.html` and `.xml` extensions::

         from jinja2 import Environment, select_autoescape
         env = Environment(autoescape=select_autoescape(
             enabled_extensions=('html', 'xml'),
             default_for_string=True,
         ))

     Example configuration to turn it on at all times except if the template
     ends with `.txt`::

         from jinja2 import Environment, select_autoescape
         env = Environment(autoescape=select_autoescape(
             disabled_extensions=('txt',),
             default_for_string=True,
             default=True,
         ))

     The `enabled_extensions` is an iterable of all the extensions that
     autoescaping should be enabled for.  Likewise `disabled_extensions` is
     a list of all templates it should be disabled for.  If a template is
     loaded from a string then the default from `default_for_string` is used.
     If nothing matches then the initial value of autoescaping is set to the
     value of `default`.

     For security reasons this function operates case insensitive.

     .. versionadded:: 2.9
     """
     enabled_patterns = tuple(f".{x.lstrip('.').lower()}" for x in enabled_extensions)
     disabled_patterns = tuple(f".{x.lstrip('.').lower()}" for x in disabled_extensions)

     def autoescape(template_name: t.Optional[str]) -> bool:
         if template_name is None:
             return default_for_string
         template_name = template_name.lower()
         if template_name.endswith(enabled_patterns):
             return True
         if template_name.endswith(disabled_patterns):
             return False
         return default

     return autoescape


 def htmlsafe_json_dumps(
     obj: t.Any, dumps: t.Optional[t.Callable[..., str]] = None, **kwargs: t.Any
 ) -> markupsafe.Markup:
     """Serialize an object to a string of JSON with :func:`json.dumps`,
     then replace HTML-unsafe characters with Unicode escapes and mark
     the result safe with :class:`~markupsafe.Markup`.

     This is available in templates as the ``|tojson`` filter.

     The following characters are escaped: ``<``, ``>``, ``&``, ``'``.

     The returned string is safe to render in HTML documents and
     ``<script>`` tags. The exception is in HTML attributes that are
     double quoted; either use single quotes or the ``|forceescape``
     filter.

     :param obj: The object to serialize to JSON.
     :param dumps: The ``dumps`` function to use. Defaults to
         ``env.policies["json.dumps_function"]``, which defaults to
         :func:`json.dumps`.
     :param kwargs: Extra arguments to pass to ``dumps``. Merged onto
         ``env.policies["json.dumps_kwargs"]``.

     .. versionchanged:: 3.0
         The ``dumper`` parameter is renamed to ``dumps``.

     .. versionadded:: 2.9
     """
     if dumps is None:
         dumps = json.dumps

     return markupsafe.Markup(
         dumps(obj, **kwargs)
         .replace("<", "\\u003c")
         .replace(">", "\\u003e")
         .replace("&", "\\u0026")
         .replace("'", "\\u0027")
     )


 class Cycler:
     """Cycle through values by yield them one at a time, then restarting
     once the end is reached. Available as ``cycler`` in templates.

     Similar to ``loop.cycle``, but can be used outside loops or across
     multiple loops. For example, render a list of folders and files in a
     list, alternating giving them "odd" and "even" classes.

     .. code-block:: html+jinja

         {% set row_class = cycler("odd", "even") %}
         <ul class="browser">
         {% for folder in folders %}
           <li class="folder {{ row_class.next() }}">{{ folder }}
         {% endfor %}
         {% for file in files %}
           <li class="file {{ row_class.next() }}">{{ file }}
         {% endfor %}
         </ul>

     :param items: Each positional argument will be yielded in the order
         given for each cycle.

     .. versionadded:: 2.1
     """

     def __init__(self, *items: t.Any) -> None:
         if not items:
             raise RuntimeError("at least one item has to be provided")
         self.items = items
         self.pos = 0

     def reset(self) -> None:
         """Resets the current item to the first item."""
         self.pos = 0

     @property
     def current(self) -> t.Any:
         """Return the current item. Equivalent to the item that will be
         returned next time :meth:`next` is called.
         """
         return self.items[self.pos]

     def next(self) -> t.Any:
         """Return the current item, then advance :attr:`current` to the
         next item.
         """
         rv = self.current
         self.pos = (self.pos + 1) % len(self.items)
         return rv

     __next__ = next


 class Joiner:
     """A joining helper for templates."""

     def __init__(self, sep: str = ", ") -> None:
         self.sep = sep
         self.used = False

     def __call__(self) -> str:
         if not self.used:
             self.used = True
             return ""
         return self.sep


 class Namespace:
     """A namespace object that can hold arbitrary attributes.  It may be
     initialized from a dictionary or with keyword arguments."""

     def __init__(*args: t.Any, **kwargs: t.Any) -> None:  # noqa: B902
         self, args = args[0], args[1:]
         self.__attrs = dict(*args, **kwargs)

     def __getattribute__(self, name: str) -> t.Any:
         # __class__ is needed for the awaitable check in async mode
         if name in {"_Namespace__attrs", "__class__"}:
             return object.__getattribute__(self, name)
         try:
             return self.__attrs[name]
         except KeyError:
             raise AttributeError(name) from None

     def __setitem__(self, name: str, value: t.Any) -> None:
         self.__attrs[name] = value

     def __repr__(self) -> str:
         return f"<Namespace {self.__attrs!r}>"
	import enum
	import json
	import os
	import re
	import typing as t
	from collections import abc
	from collections import deque
	from random import choice
	from random import randrange
	from threading import Lock
	from types import CodeType
	from urllib.parse import quote_from_bytes

	import markupsafe

	if t.TYPE_CHECKING:
	import typing_extensions as te

	F = t.TypeVar("F", bound=t.Callable[..., t.Any])

	# special singleton representing missing values for the runtime
	missing: t.Any = type("MissingType", (), {"__repr__": lambda x: "missing"})()

	internal_code: t.MutableSet[CodeType] = set()

	concat = "".join


	def pass_context(f: F) -> F:
	"""Pass the :class:`~jinja2.runtime.Context` as the first argument
	to the decorated function when called while rendering a template.

	Can be used on functions, filters, and tests.

	If only ``Context.eval_context`` is needed, use
	:func:`pass_eval_context`. If only ``Context.environment`` is
	needed, use :func:`pass_environment`.

	.. versionadded:: 3.0.0
	Replaces ``contextfunction`` and ``contextfilter``.
	"""
	f.jinja_pass_arg = _PassArg.context # type: ignore
	return f


	def pass_eval_context(f: F) -> F:
	"""Pass the :class:`~jinja2.nodes.EvalContext` as the first argument
	to the decorated function when called while rendering a template.
	See :ref:`eval-context`.

	Can be used on functions, filters, and tests.

	If only ``EvalContext.environment`` is needed, use
	:func:`pass_environment`.

	.. versionadded:: 3.0.0
	Replaces ``evalcontextfunction`` and ``evalcontextfilter``.
	"""
	f.jinja_pass_arg = _PassArg.eval_context # type: ignore
	return f


	def pass_environment(f: F) -> F:
	"""Pass the :class:`~jinja2.Environment` as the first argument to
	the decorated function when called while rendering a template.

	Can be used on functions, filters, and tests.

	.. versionadded:: 3.0.0
	Replaces ``environmentfunction`` and ``environmentfilter``.
	"""
	f.jinja_pass_arg = _PassArg.environment # type: ignore
	return f


	class _PassArg(enum.Enum):
	context = enum.auto()
	eval_context = enum.auto()
	environment = enum.auto()

	@classmethod
	def from_obj(cls, obj: F) -> t.Optional["_PassArg"]:
	if hasattr(obj, "jinja_pass_arg"):
	return obj.jinja_pass_arg # type: ignore

	return None


	def internalcode(f: F) -> F:
	"""Marks the function as internally used"""
	internal_code.add(f.__code__)
	return f


	def is_undefined(obj: t.Any) -> bool:
	"""Check if the object passed is undefined. This does nothing more than
	performing an instance check against :class:`Undefined` but looks nicer.
	This can be used for custom filters or tests that want to react to
	undefined variables. For example a custom default filter can look like
	this::

	def default(var, default=''):
	if is_undefined(var):
	return default
	return var
	"""
	from .runtime import Undefined

	return isinstance(obj, Undefined)


	def consume(iterable: t.Iterable[t.Any]) -> None:
	"""Consumes an iterable without doing anything with it."""
	for _ in iterable:
	pass


	def clear_caches() -> None:
	"""Jinja keeps internal caches for environments and lexers. These are
	used so that Jinja doesn't have to recreate environments and lexers all
	the time. Normally you don't have to care about that but if you are
	measuring memory consumption you may want to clean the caches.
	"""
	from .environment import get_spontaneous_environment
	from .lexer import _lexer_cache

	get_spontaneous_environment.cache_clear()
	_lexer_cache.clear()


	def import_string(import_name: str, silent: bool = False) -> t.Any:
	"""Imports an object based on a string. This is useful if you want to
	use import paths as endpoints or something similar. An import path can
	be specified either in dotted notation (``xml.sax.saxutils.escape``)
	or with a colon as object delimiter (``xml.sax.saxutils:escape``).

	If the `silent` is True the return value will be `None` if the import
	fails.

	:return: imported object
	"""
	try:
	if ":" in import_name:
	module, obj = import_name.split(":", 1)
	elif "." in import_name:
	module, _, obj = import_name.rpartition(".")
	else:
	return __import__(import_name)
	return getattr(__import__(module, None, None, [obj]), obj)
	except (ImportError, AttributeError):
	if not silent:
	raise


	def open_if_exists(filename: str, mode: str = "rb") -> t.Optional[t.IO]:
	"""Returns a file descriptor for the filename if that file exists,
	otherwise ``None``.
	"""
	if not os.path.isfile(filename):
	return None

	return open(filename, mode)


	def object_type_repr(obj: t.Any) -> str:
	"""Returns the name of the object's type. For some recognized
	singletons the name of the object is returned instead. (For
	example for `None` and `Ellipsis`).
	"""
	if obj is None:
	return "None"
	elif obj is Ellipsis:
	return "Ellipsis"

	cls = type(obj)

	if cls.__module__ == "builtins":
	return f"{cls.__name__} object"

	return f"{cls.__module__}.{cls.__name__} object"


	def pformat(obj: t.Any) -> str:
	"""Format an object using :func:`pprint.pformat`."""
	from pprint import pformat # type: ignore

	return pformat(obj)


	_http_re = re.compile(
	r"""
	^
	(
	(https?://\|www\.) # scheme or www
	(([\w%-]+\.)+)? # subdomain
	(
	[a-z]{2,63} # basic tld
	\|
	xn--[\w%]{2,59} # idna tld
	)
	\|
	([\w%-]{2,63}\.)+ # basic domain
	(com\|net\|int\|edu\|gov\|org\|info\|mil) # basic tld
	\|
	(https?://) # scheme
	(
	(([\d]{1,3})(\.[\d]{1,3}){3}) # IPv4
	\|
	(\[([\da-f]{0,4}:){2}([\da-f]{0,4}:?){1,6}]) # IPv6
	)
	)
	(?::[\d]{1,5})? # port
	(?:[/?#]\S*)? # path, query, and fragment
	$
	""",
	re.IGNORECASE \| re.VERBOSE,
	)
	_email_re = re.compile(r"^\S+@\w[\w.-]*\.\w+$")


	def urlize(
	text: str,
	trim_url_limit: t.Optional[int] = None,
	rel: t.Optional[str] = None,
	target: t.Optional[str] = None,
	extra_schemes: t.Optional[t.Iterable[str]] = None,
	) -> str:
	"""Convert URLs in text into clickable links.

	This may not recognize links in some situations. Usually, a more
	comprehensive formatter, such as a Markdown library, is a better
	choice.

	Works on ``http://``, ``https://``, ``www.``, ``mailto:``, and email
	addresses. Links with trailing punctuation (periods, commas, closing
	parentheses) and leading punctuation (opening parentheses) are
	recognized excluding the punctuation. Email addresses that include
	header fields are not recognized (for example,
	``mailto:address@example.com?cc=copy@example.com``).

	:param text: Original text containing URLs to link.
	:param trim_url_limit: Shorten displayed URL values to this length.
	:param target: Add the ``target`` attribute to links.
	:param rel: Add the ``rel`` attribute to links.
	:param extra_schemes: Recognize URLs that start with these schemes
	in addition to the default behavior.

	.. versionchanged:: 3.0
	The ``extra_schemes`` parameter was added.

	.. versionchanged:: 3.0
	Generate ``https://`` links for URLs without a scheme.

	.. versionchanged:: 3.0
	The parsing rules were updated. Recognize email addresses with
	or without the ``mailto:`` scheme. Validate IP addresses. Ignore
	parentheses and brackets in more cases.
	"""
	if trim_url_limit is not None:

	def trim_url(x: str) -> str:
	if len(x) > trim_url_limit: # type: ignore
	return f"{x[:trim_url_limit]}..."

	return x

	else:

	def trim_url(x: str) -> str:
	return x

	words = re.split(r"(\s+)", str(markupsafe.escape(text)))
	rel_attr = f' rel="{markupsafe.escape(rel)}"' if rel else ""
	target_attr = f' target="{markupsafe.escape(target)}"' if target else ""

	for i, word in enumerate(words):
	head, middle, tail = "", word, ""
	match = re.match(r"^([(<]\|<)+", middle)

	if match:
	head = match.group()
	middle = middle[match.end() :]

	# Unlike lead, which is anchored to the start of the string,
	# need to check that the string ends with any of the characters
	# before trying to match all of them, to avoid backtracking.
	if middle.endswith((")", ">", ".", ",", "\n", ">")):
	match = re.search(r"([)>.,\n]\|>)+$", middle)

	if match:
	tail = match.group()
	middle = middle[: match.start()]

	# Prefer balancing parentheses in URLs instead of ignoring a
	# trailing character.
	for start_char, end_char in ("(", ")"), ("<", ">"), ("<", ">"):
	start_count = middle.count(start_char)

	if start_count <= middle.count(end_char):
	# Balanced, or lighter on the left
	continue

	# Move as many as possible from the tail to balance
	for _ in range(min(start_count, tail.count(end_char))):
	end_index = tail.index(end_char) + len(end_char)
	# Move anything in the tail before the end char too
	middle += tail[:end_index]
	tail = tail[end_index:]

	if _http_re.match(middle):
	if middle.startswith("https://") or middle.startswith("http://"):
	middle = (
	f'<a href="{middle}"{rel_attr}{target_attr}>{trim_url(middle)}</a>'
	)
	else:
	middle = (
	f'<a href="https://{middle}"{rel_attr}{target_attr}>'
	f"{trim_url(middle)}</a>"
	)

	elif middle.startswith("mailto:") and _email_re.match(middle[7:]):
	middle = f'<a href="{middle}">{middle[7:]}</a>'

	elif (
	"@" in middle
	and not middle.startswith("www.")
	and ":" not in middle
	and _email_re.match(middle)
	):
	middle = f'<a href="mailto:{middle}">{middle}</a>'

	elif extra_schemes is not None:
	for scheme in extra_schemes:
	if middle != scheme and middle.startswith(scheme):
	middle = f'<a href="{middle}"{rel_attr}{target_attr}>{middle}</a>'

	words[i] = f"{head}{middle}{tail}"

	return "".join(words)


	def generate_lorem_ipsum(
	n: int = 5, html: bool = True, min: int = 20, max: int = 100
	) -> str:
	"""Generate some lorem ipsum for the template."""
	from .constants import LOREM_IPSUM_WORDS

	words = LOREM_IPSUM_WORDS.split()
	result = []

	for _ in range(n):
	next_capitalized = True
	last_comma = last_fullstop = 0
	word = None
	last = None
	p = []

	# each paragraph contains out of 20 to 100 words.
	for idx, _ in enumerate(range(randrange(min, max))):
	while True:
	word = choice(words)
	if word != last:
	last = word
	break
	if next_capitalized:
	word = word.capitalize()
	next_capitalized = False
	# add commas
	if idx - randrange(3, 8) > last_comma:
	last_comma = idx
	last_fullstop += 2
	word += ","
	# add end of sentences
	if idx - randrange(10, 20) > last_fullstop:
	last_comma = last_fullstop = idx
	word += "."
	next_capitalized = True
	p.append(word)

	# ensure that the paragraph ends with a dot.
	p_str = " ".join(p)

	if p_str.endswith(","):
	p_str = p_str[:-1] + "."
	elif not p_str.endswith("."):
	p_str += "."

	result.append(p_str)

	if not html:
	return "\n\n".join(result)
	return markupsafe.Markup(
	"\n".join(f"<p>{markupsafe.escape(x)}</p>" for x in result)
	)


	def url_quote(obj: t.Any, charset: str = "utf-8", for_qs: bool = False) -> str:
	"""Quote a string for use in a URL using the given charset.

	:param obj: String or bytes to quote. Other types are converted to
	string then encoded to bytes using the given charset.
	:param charset: Encode text to bytes using this charset.
	:param for_qs: Quote "/" and use "+" for spaces.
	"""
	if not isinstance(obj, bytes):
	if not isinstance(obj, str):
	obj = str(obj)

	obj = obj.encode(charset)

	safe = b"" if for_qs else b"/"
	rv = quote_from_bytes(obj, safe)

	if for_qs:
	rv = rv.replace("%20", "+")

	return rv


	@abc.MutableMapping.register
	class LRUCache:
	"""A simple LRU Cache implementation."""

	# this is fast for small capacities (something below 1000) but doesn't
	# scale. But as long as it's only used as storage for templates this
	# won't do any harm.

	def __init__(self, capacity: int) -> None:
	self.capacity = capacity
	self._mapping: t.Dict[t.Any, t.Any] = {}
	self._queue: "te.Deque[t.Any]" = deque()
	self._postinit()

	def _postinit(self) -> None:
	# alias all queue methods for faster lookup
	self._popleft = self._queue.popleft
	self._pop = self._queue.pop
	self._remove = self._queue.remove
	self._wlock = Lock()
	self._append = self._queue.append

	def __getstate__(self) -> t.Mapping[str, t.Any]:
	return {
	"capacity": self.capacity,
	"_mapping": self._mapping,
	"_queue": self._queue,
	}

	def __setstate__(self, d: t.Mapping[str, t.Any]) -> None:
	self.__dict__.update(d)
	self._postinit()

	def __getnewargs__(self) -> t.Tuple:
	return (self.capacity,)

	def copy(self) -> "LRUCache":
	"""Return a shallow copy of the instance."""
	rv = self.__class__(self.capacity)
	rv._mapping.update(self._mapping)
	rv._queue.extend(self._queue)
	return rv

	def get(self, key: t.Any, default: t.Any = None) -> t.Any:
	"""Return an item from the cache dict or `default`"""
	try:
	return self[key]
	except KeyError:
	return default

	def setdefault(self, key: t.Any, default: t.Any = None) -> t.Any:
	"""Set `default` if the key is not in the cache otherwise
	leave unchanged. Return the value of this key.
	"""
	try:
	return self[key]
	except KeyError:
	self[key] = default
	return default

	def clear(self) -> None:
	"""Clear the cache."""
	with self._wlock:
	self._mapping.clear()
	self._queue.clear()

	def __contains__(self, key: t.Any) -> bool:
	"""Check if a key exists in this cache."""
	return key in self._mapping

	def __len__(self) -> int:
	"""Return the current size of the cache."""
	return len(self._mapping)

	def __repr__(self) -> str:
	return f"<{type(self).__name__} {self._mapping!r}>"

	def __getitem__(self, key: t.Any) -> t.Any:
	"""Get an item from the cache. Moves the item up so that it has the
	highest priority then.

	Raise a `KeyError` if it does not exist.
	"""
	with self._wlock:
	rv = self._mapping[key]

	if self._queue[-1] != key:
	try:
	self._remove(key)
	except ValueError:
	# if something removed the key from the container
	# when we read, ignore the ValueError that we would
	# get otherwise.
	pass

	self._append(key)

	return rv

	def __setitem__(self, key: t.Any, value: t.Any) -> None:
	"""Sets the value for an item. Moves the item up so that it
	has the highest priority then.
	"""
	with self._wlock:
	if key in self._mapping:
	self._remove(key)
	elif len(self._mapping) == self.capacity:
	del self._mapping[self._popleft()]

	self._append(key)
	self._mapping[key] = value

	def __delitem__(self, key: t.Any) -> None:
	"""Remove an item from the cache dict.
	Raise a `KeyError` if it does not exist.
	"""
	with self._wlock:
	del self._mapping[key]

	try:
	self._remove(key)
	except ValueError:
	pass

	def items(self) -> t.Iterable[t.Tuple[t.Any, t.Any]]:
	"""Return a list of items."""
	result = [(key, self._mapping[key]) for key in list(self._queue)]
	result.reverse()
	return result

	def values(self) -> t.Iterable[t.Any]:
	"""Return a list of all values."""
	return [x[1] for x in self.items()]

	def keys(self) -> t.Iterable[t.Any]:
	"""Return a list of all keys ordered by most recent usage."""
	return list(self)

	def __iter__(self) -> t.Iterator[t.Any]:
	return reversed(tuple(self._queue))

	def __reversed__(self) -> t.Iterator[t.Any]:
	"""Iterate over the keys in the cache dict, oldest items
	coming first.
	"""
	return iter(tuple(self._queue))

	__copy__ = copy


	def select_autoescape(
	enabled_extensions: t.Collection[str] = ("html", "htm", "xml"),
	disabled_extensions: t.Collection[str] = (),
	default_for_string: bool = True,
	default: bool = False,
	) -> t.Callable[[t.Optional[str]], bool]:
	"""Intelligently sets the initial value of autoescaping based on the
	filename of the template. This is the recommended way to configure
	autoescaping if you do not want to write a custom function yourself.

	If you want to enable it for all templates created from strings or
	for all templates with `.html` and `.xml` extensions::

	from jinja2 import Environment, select_autoescape
	env = Environment(autoescape=select_autoescape(
	enabled_extensions=('html', 'xml'),
	default_for_string=True,
	))

	Example configuration to turn it on at all times except if the template
	ends with `.txt`::

	from jinja2 import Environment, select_autoescape
	env = Environment(autoescape=select_autoescape(
	disabled_extensions=('txt',),
	default_for_string=True,
	default=True,
	))

	The `enabled_extensions` is an iterable of all the extensions that
	autoescaping should be enabled for. Likewise `disabled_extensions` is
	a list of all templates it should be disabled for. If a template is
	loaded from a string then the default from `default_for_string` is used.
	If nothing matches then the initial value of autoescaping is set to the
	value of `default`.

	For security reasons this function operates case insensitive.

	.. versionadded:: 2.9
	"""
	enabled_patterns = tuple(f".{x.lstrip('.').lower()}" for x in enabled_extensions)
	disabled_patterns = tuple(f".{x.lstrip('.').lower()}" for x in disabled_extensions)

	def autoescape(template_name: t.Optional[str]) -> bool:
	if template_name is None:
	return default_for_string
	template_name = template_name.lower()
	if template_name.endswith(enabled_patterns):
	return True
	if template_name.endswith(disabled_patterns):
	return False
	return default

	return autoescape


	def htmlsafe_json_dumps(
	obj: t.Any, dumps: t.Optional[t.Callable[..., str]] = None, **kwargs: t.Any
	) -> markupsafe.Markup:
	"""Serialize an object to a string of JSON with :func:`json.dumps`,
	then replace HTML-unsafe characters with Unicode escapes and mark
	the result safe with :class:`~markupsafe.Markup`.

	This is available in templates as the ``\|tojson`` filter.

	The following characters are escaped: ``<``, ``>``, ``&``, ``'``.

	The returned string is safe to render in HTML documents and
	``<script>`` tags. The exception is in HTML attributes that are
	double quoted; either use single quotes or the ``\|forceescape``
	filter.

	:param obj: The object to serialize to JSON.
	:param dumps: The ``dumps`` function to use. Defaults to
	``env.policies["json.dumps_function"]``, which defaults to
	:func:`json.dumps`.
	:param kwargs: Extra arguments to pass to ``dumps``. Merged onto
	``env.policies["json.dumps_kwargs"]``.

	.. versionchanged:: 3.0
	The ``dumper`` parameter is renamed to ``dumps``.

	.. versionadded:: 2.9
	"""
	if dumps is None:
	dumps = json.dumps

	return markupsafe.Markup(
	dumps(obj, **kwargs)
	.replace("<", "\\u003c")
	.replace(">", "\\u003e")
	.replace("&", "\\u0026")
	.replace("'", "\\u0027")
	)


	class Cycler:
	"""Cycle through values by yield them one at a time, then restarting
	once the end is reached. Available as ``cycler`` in templates.

	Similar to ``loop.cycle``, but can be used outside loops or across
	multiple loops. For example, render a list of folders and files in a
	list, alternating giving them "odd" and "even" classes.

	.. code-block:: html+jinja

	{% set row_class = cycler("odd", "even") %}
	<ul class="browser">
	{% for folder in folders %}
	<li class="folder {{ row_class.next() }}">{{ folder }}
	{% endfor %}
	{% for file in files %}
	<li class="file {{ row_class.next() }}">{{ file }}
	{% endfor %}
	</ul>

	:param items: Each positional argument will be yielded in the order
	given for each cycle.

	.. versionadded:: 2.1
	"""

	def __init__(self, *items: t.Any) -> None:
	if not items:
	raise RuntimeError("at least one item has to be provided")
	self.items = items
	self.pos = 0

	def reset(self) -> None:
	"""Resets the current item to the first item."""
	self.pos = 0

	@property
	def current(self) -> t.Any:
	"""Return the current item. Equivalent to the item that will be
	returned next time :meth:`next` is called.
	"""
	return self.items[self.pos]

	def next(self) -> t.Any:
	"""Return the current item, then advance :attr:`current` to the
	next item.
	"""
	rv = self.current
	self.pos = (self.pos + 1) % len(self.items)
	return rv

	__next__ = next


	class Joiner:
	"""A joining helper for templates."""

	def __init__(self, sep: str = ", ") -> None:
	self.sep = sep
	self.used = False

	def __call__(self) -> str:
	if not self.used:
	self.used = True
	return ""
	return self.sep


	class Namespace:
	"""A namespace object that can hold arbitrary attributes. It may be
	initialized from a dictionary or with keyword arguments."""

	def __init__(args: t.Any, *kwargs: t.Any) -> None: # noqa: B902
	self, args = args[0], args[1:]
	self.__attrs = dict(args, *kwargs)

	def __getattribute__(self, name: str) -> t.Any:
	# __class__ is needed for the awaitable check in async mode
	if name in {"_Namespace__attrs", "__class__"}:
	return object.__getattribute__(self, name)
	try:
	return self.__attrs[name]
	except KeyError:
	raise AttributeError(name) from None

	def __setitem__(self, name: str, value: t.Any) -> None:
	self.__attrs[name] = value

	def __repr__(self) -> str:
	return f"<Namespace {self.__attrs!r}>"