Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1667 insertions, 0 deletions

diff --git a/third_party/python/Jinja2/jinja2/environment.py b/third_party/python/Jinja2/jinja2/environment.py
new file mode 100644
index 0000000000..ea04e8b443
--- /dev/null
+++ b/third_party/python/Jinja2/jinja2/environment.py
@@ -0,0 +1,1667 @@
+"""Classes for managing templates and their runtime and compile time
+options.
+"""
+import os
+import typing
+import typing as t
+import weakref
+from collections import ChainMap
+from functools import lru_cache
+from functools import partial
+from functools import reduce
+from types import CodeType
+
+from markupsafe import Markup
+
+from . import nodes
+from .compiler import CodeGenerator
+from .compiler import generate
+from .defaults import BLOCK_END_STRING
+from .defaults import BLOCK_START_STRING
+from .defaults import COMMENT_END_STRING
+from .defaults import COMMENT_START_STRING
+from .defaults import DEFAULT_FILTERS
+from .defaults import DEFAULT_NAMESPACE
+from .defaults import DEFAULT_POLICIES
+from .defaults import DEFAULT_TESTS
+from .defaults import KEEP_TRAILING_NEWLINE
+from .defaults import LINE_COMMENT_PREFIX
+from .defaults import LINE_STATEMENT_PREFIX
+from .defaults import LSTRIP_BLOCKS
+from .defaults import NEWLINE_SEQUENCE
+from .defaults import TRIM_BLOCKS
+from .defaults import VARIABLE_END_STRING
+from .defaults import VARIABLE_START_STRING
+from .exceptions import TemplateNotFound
+from .exceptions import TemplateRuntimeError
+from .exceptions import TemplatesNotFound
+from .exceptions import TemplateSyntaxError
+from .exceptions import UndefinedError
+from .lexer import get_lexer
+from .lexer import Lexer
+from .lexer import TokenStream
+from .nodes import EvalContext
+from .parser import Parser
+from .runtime import Context
+from .runtime import new_context
+from .runtime import Undefined
+from .utils import _PassArg
+from .utils import concat
+from .utils import consume
+from .utils import import_string
+from .utils import internalcode
+from .utils import LRUCache
+from .utils import missing
+
+if t.TYPE_CHECKING:
+    import typing_extensions as te
+    from .bccache import BytecodeCache
+    from .ext import Extension
+    from .loaders import BaseLoader
+
+_env_bound = t.TypeVar("_env_bound", bound="Environment")
+
+
+# for direct template usage we have up to ten living environments
+@lru_cache(maxsize=10)
+def get_spontaneous_environment(cls: t.Type[_env_bound], *args: t.Any) -> _env_bound:
+    """Return a new spontaneous environment. A spontaneous environment
+    is used for templates created directly rather than through an
+    existing environment.
+
+    :param cls: Environment class to create.
+    :param args: Positional arguments passed to environment.
+    """
+    env = cls(*args)
+    env.shared = True
+    return env
+
+
+def create_cache(
+    size: int,
+) -> t.Optional[t.MutableMapping[t.Tuple[weakref.ref, str], "Template"]]:
+    """Return the cache class for the given size."""
+    if size == 0:
+        return None
+
+    if size < 0:
+        return {}
+
+    return LRUCache(size)  # type: ignore
+
+
+def copy_cache(
+    cache: t.Optional[t.MutableMapping],
+) -> t.Optional[t.MutableMapping[t.Tuple[weakref.ref, str], "Template"]]:
+    """Create an empty copy of the given cache."""
+    if cache is None:
+        return None
+
+    if type(cache) is dict:
+        return {}
+
+    return LRUCache(cache.capacity)  # type: ignore
+
+
+def load_extensions(
+    environment: "Environment",
+    extensions: t.Sequence[t.Union[str, t.Type["Extension"]]],
+) -> t.Dict[str, "Extension"]:
+    """Load the extensions from the list and bind it to the environment.
+    Returns a dict of instantiated extensions.
+    """
+    result = {}
+
+    for extension in extensions:
+        if isinstance(extension, str):
+            extension = t.cast(t.Type["Extension"], import_string(extension))
+
+        result[extension.identifier] = extension(environment)
+
+    return result
+
+
+def _environment_config_check(environment: "Environment") -> "Environment":
+    """Perform a sanity check on the environment."""
+    assert issubclass(
+        environment.undefined, Undefined
+    ), "'undefined' must be a subclass of 'jinja2.Undefined'."
+    assert (
+        environment.block_start_string
+        != environment.variable_start_string
+        != environment.comment_start_string
+    ), "block, variable and comment start strings must be different."
+    assert environment.newline_sequence in {
+        "\r",
+        "\r\n",
+        "\n",
+    }, "'newline_sequence' must be one of '\\n', '\\r\\n', or '\\r'."
+    return environment
+
+
+class Environment:
+    r"""The core component of Jinja is the `Environment`.  It contains
+    important shared variables like configuration, filters, tests,
+    globals and others.  Instances of this class may be modified if
+    they are not shared and if no template was loaded so far.
+    Modifications on environments after the first template was loaded
+    will lead to surprising effects and undefined behavior.
+
+    Here are the possible initialization parameters:
+
+        `block_start_string`
+            The string marking the beginning of a block.  Defaults to ``'{%'``.
+
+        `block_end_string`
+            The string marking the end of a block.  Defaults to ``'%}'``.
+
+        `variable_start_string`
+            The string marking the beginning of a print statement.
+            Defaults to ``'{{'``.
+
+        `variable_end_string`
+            The string marking the end of a print statement.  Defaults to
+            ``'}}'``.
+
+        `comment_start_string`
+            The string marking the beginning of a comment.  Defaults to ``'{#'``.
+
+        `comment_end_string`
+            The string marking the end of a comment.  Defaults to ``'#}'``.
+
+        `line_statement_prefix`
+            If given and a string, this will be used as prefix for line based
+            statements.  See also :ref:`line-statements`.
+
+        `line_comment_prefix`
+            If given and a string, this will be used as prefix for line based
+            comments.  See also :ref:`line-statements`.
+
+            .. versionadded:: 2.2
+
+        `trim_blocks`
+            If this is set to ``True`` the first newline after a block is
+            removed (block, not variable tag!).  Defaults to `False`.
+
+        `lstrip_blocks`
+            If this is set to ``True`` leading spaces and tabs are stripped
+            from the start of a line to a block.  Defaults to `False`.
+
+        `newline_sequence`
+            The sequence that starts a newline.  Must be one of ``'\r'``,
+            ``'\n'`` or ``'\r\n'``.  The default is ``'\n'`` which is a
+            useful default for Linux and OS X systems as well as web
+            applications.
+
+        `keep_trailing_newline`
+            Preserve the trailing newline when rendering templates.
+            The default is ``False``, which causes a single newline,
+            if present, to be stripped from the end of the template.
+
+            .. versionadded:: 2.7
+
+        `extensions`
+            List of Jinja extensions to use.  This can either be import paths
+            as strings or extension classes.  For more information have a
+            look at :ref:`the extensions documentation <jinja-extensions>`.
+
+        `optimized`
+            should the optimizer be enabled?  Default is ``True``.
+
+        `undefined`
+            :class:`Undefined` or a subclass of it that is used to represent
+            undefined values in the template.
+
+        `finalize`
+            A callable that can be used to process the result of a variable
+            expression before it is output.  For example one can convert
+            ``None`` implicitly into an empty string here.
+
+        `autoescape`
+            If set to ``True`` the XML/HTML autoescaping feature is enabled by
+            default.  For more details about autoescaping see
+            :class:`~markupsafe.Markup`.  As of Jinja 2.4 this can also
+            be a callable that is passed the template name and has to
+            return ``True`` or ``False`` depending on autoescape should be
+            enabled by default.
+
+            .. versionchanged:: 2.4
+               `autoescape` can now be a function
+
+        `loader`
+            The template loader for this environment.
+
+        `cache_size`
+            The size of the cache.  Per default this is ``400`` which means
+            that if more than 400 templates are loaded the loader will clean
+            out the least recently used template.  If the cache size is set to
+            ``0`` templates are recompiled all the time, if the cache size is
+            ``-1`` the cache will not be cleaned.
+
+            .. versionchanged:: 2.8
+               The cache size was increased to 400 from a low 50.
+
+        `auto_reload`
+            Some loaders load templates from locations where the template
+            sources may change (ie: file system or database).  If
+            ``auto_reload`` is set to ``True`` (default) every time a template is
+            requested the loader checks if the source changed and if yes, it
+            will reload the template.  For higher performance it's possible to
+            disable that.
+
+        `bytecode_cache`
+            If set to a bytecode cache object, this object will provide a
+            cache for the internal Jinja bytecode so that templates don't
+            have to be parsed if they were not changed.
+
+            See :ref:`bytecode-cache` for more information.
+
+        `enable_async`
+            If set to true this enables async template execution which
+            allows using async functions and generators.
+    """
+
+    #: if this environment is sandboxed.  Modifying this variable won't make
+    #: the environment sandboxed though.  For a real sandboxed environment
+    #: have a look at jinja2.sandbox.  This flag alone controls the code
+    #: generation by the compiler.
+    sandboxed = False
+
+    #: True if the environment is just an overlay
+    overlayed = False
+
+    #: the environment this environment is linked to if it is an overlay
+    linked_to: t.Optional["Environment"] = None
+
+    #: shared environments have this set to `True`.  A shared environment
+    #: must not be modified
+    shared = False
+
+    #: the class that is used for code generation.  See
+    #: :class:`~jinja2.compiler.CodeGenerator` for more information.
+    code_generator_class: t.Type["CodeGenerator"] = CodeGenerator
+
+    concat = "".join
+
+    #: the context class that is used for templates.  See
+    #: :class:`~jinja2.runtime.Context` for more information.
+    context_class: t.Type[Context] = Context
+
+    template_class: t.Type["Template"]
+
+    def __init__(
+        self,
+        block_start_string: str = BLOCK_START_STRING,
+        block_end_string: str = BLOCK_END_STRING,
+        variable_start_string: str = VARIABLE_START_STRING,
+        variable_end_string: str = VARIABLE_END_STRING,
+        comment_start_string: str = COMMENT_START_STRING,
+        comment_end_string: str = COMMENT_END_STRING,
+        line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX,
+        line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX,
+        trim_blocks: bool = TRIM_BLOCKS,
+        lstrip_blocks: bool = LSTRIP_BLOCKS,
+        newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE,
+        keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE,
+        extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (),
+        optimized: bool = True,
+        undefined: t.Type[Undefined] = Undefined,
+        finalize: t.Optional[t.Callable[..., t.Any]] = None,
+        autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False,
+        loader: t.Optional["BaseLoader"] = None,
+        cache_size: int = 400,
+        auto_reload: bool = True,
+        bytecode_cache: t.Optional["BytecodeCache"] = None,
+        enable_async: bool = False,
+    ):
+        # !!Important notice!!
+        #   The constructor accepts quite a few arguments that should be
+        #   passed by keyword rather than position.  However it's important to
+        #   not change the order of arguments because it's used at least
+        #   internally in those cases:
+        #       -   spontaneous environments (i18n extension and Template)
+        #       -   unittests
+        #   If parameter changes are required only add parameters at the end
+        #   and don't change the arguments (or the defaults!) of the arguments
+        #   existing already.
+
+        # lexer / parser information
+        self.block_start_string = block_start_string
+        self.block_end_string = block_end_string
+        self.variable_start_string = variable_start_string
+        self.variable_end_string = variable_end_string
+        self.comment_start_string = comment_start_string
+        self.comment_end_string = comment_end_string
+        self.line_statement_prefix = line_statement_prefix
+        self.line_comment_prefix = line_comment_prefix
+        self.trim_blocks = trim_blocks
+        self.lstrip_blocks = lstrip_blocks
+        self.newline_sequence = newline_sequence
+        self.keep_trailing_newline = keep_trailing_newline
+
+        # runtime information
+        self.undefined: t.Type[Undefined] = undefined
+        self.optimized = optimized
+        self.finalize = finalize
+        self.autoescape = autoescape
+
+        # defaults
+        self.filters = DEFAULT_FILTERS.copy()
+        self.tests = DEFAULT_TESTS.copy()
+        self.globals = DEFAULT_NAMESPACE.copy()
+
+        # set the loader provided
+        self.loader = loader
+        self.cache = create_cache(cache_size)
+        self.bytecode_cache = bytecode_cache
+        self.auto_reload = auto_reload
+
+        # configurable policies
+        self.policies = DEFAULT_POLICIES.copy()
+
+        # load extensions
+        self.extensions = load_extensions(self, extensions)
+
+        self.is_async = enable_async
+        _environment_config_check(self)
+
+    def add_extension(self, extension: t.Union[str, t.Type["Extension"]]) -> None:
+        """Adds an extension after the environment was created.
+
+        .. versionadded:: 2.5
+        """
+        self.extensions.update(load_extensions(self, [extension]))
+
+    def extend(self, **attributes: t.Any) -> None:
+        """Add the items to the instance of the environment if they do not exist
+        yet.  This is used by :ref:`extensions <writing-extensions>` to register
+        callbacks and configuration values without breaking inheritance.
+        """
+        for key, value in attributes.items():
+            if not hasattr(self, key):
+                setattr(self, key, value)
+
+    def overlay(
+        self,
+        block_start_string: str = missing,
+        block_end_string: str = missing,
+        variable_start_string: str = missing,
+        variable_end_string: str = missing,
+        comment_start_string: str = missing,
+        comment_end_string: str = missing,
+        line_statement_prefix: t.Optional[str] = missing,
+        line_comment_prefix: t.Optional[str] = missing,
+        trim_blocks: bool = missing,
+        lstrip_blocks: bool = missing,
+        newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = missing,
+        keep_trailing_newline: bool = missing,
+        extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = missing,
+        optimized: bool = missing,
+        undefined: t.Type[Undefined] = missing,
+        finalize: t.Optional[t.Callable[..., t.Any]] = missing,
+        autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = missing,
+        loader: t.Optional["BaseLoader"] = missing,
+        cache_size: int = missing,
+        auto_reload: bool = missing,
+        bytecode_cache: t.Optional["BytecodeCache"] = missing,
+        enable_async: bool = False,
+    ) -> "Environment":
+        """Create a new overlay environment that shares all the data with the
+        current environment except for cache and the overridden attributes.
+        Extensions cannot be removed for an overlayed environment.  An overlayed
+        environment automatically gets all the extensions of the environment it
+        is linked to plus optional extra extensions.
+
+        Creating overlays should happen after the initial environment was set
+        up completely.  Not all attributes are truly linked, some are just
+        copied over so modifications on the original environment may not shine
+        through.
+
+        .. versionchanged:: 3.1.2
+            Added the ``newline_sequence``,, ``keep_trailing_newline``,
+            and ``enable_async`` parameters to match ``__init__``.
+        """
+        args = dict(locals())
+        del args["self"], args["cache_size"], args["extensions"], args["enable_async"]
+
+        rv = object.__new__(self.__class__)
+        rv.__dict__.update(self.__dict__)
+        rv.overlayed = True
+        rv.linked_to = self
+
+        for key, value in args.items():
+            if value is not missing:
+                setattr(rv, key, value)
+
+        if cache_size is not missing:
+            rv.cache = create_cache(cache_size)
+        else:
+            rv.cache = copy_cache(self.cache)
+
+        rv.extensions = {}
+        for key, value in self.extensions.items():
+            rv.extensions[key] = value.bind(rv)
+        if extensions is not missing:
+            rv.extensions.update(load_extensions(rv, extensions))
+
+        if enable_async is not missing:
+            rv.is_async = enable_async
+
+        return _environment_config_check(rv)
+
+    @property
+    def lexer(self) -> Lexer:
+        """The lexer for this environment."""
+        return get_lexer(self)
+
+    def iter_extensions(self) -> t.Iterator["Extension"]:
+        """Iterates over the extensions by priority."""
+        return iter(sorted(self.extensions.values(), key=lambda x: x.priority))
+
+    def getitem(
+        self, obj: t.Any, argument: t.Union[str, t.Any]
+    ) -> t.Union[t.Any, Undefined]:
+        """Get an item or attribute of an object but prefer the item."""
+        try:
+            return obj[argument]
+        except (AttributeError, TypeError, LookupError):
+            if isinstance(argument, str):
+                try:
+                    attr = str(argument)
+                except Exception:
+                    pass
+                else:
+                    try:
+                        return getattr(obj, attr)
+                    except AttributeError:
+                        pass
+            return self.undefined(obj=obj, name=argument)
+
+    def getattr(self, obj: t.Any, attribute: str) -> t.Any:
+        """Get an item or attribute of an object but prefer the attribute.
+        Unlike :meth:`getitem` the attribute *must* be a string.
+        """
+        try:
+            return getattr(obj, attribute)
+        except AttributeError:
+            pass
+        try:
+            return obj[attribute]
+        except (TypeError, LookupError, AttributeError):
+            return self.undefined(obj=obj, name=attribute)
+
+    def _filter_test_common(
+        self,
+        name: t.Union[str, Undefined],
+        value: t.Any,
+        args: t.Optional[t.Sequence[t.Any]],
+        kwargs: t.Optional[t.Mapping[str, t.Any]],
+        context: t.Optional[Context],
+        eval_ctx: t.Optional[EvalContext],
+        is_filter: bool,
+    ) -> t.Any:
+        if is_filter:
+            env_map = self.filters
+            type_name = "filter"
+        else:
+            env_map = self.tests
+            type_name = "test"
+
+        func = env_map.get(name)  # type: ignore
+
+        if func is None:
+            msg = f"No {type_name} named {name!r}."
+
+            if isinstance(name, Undefined):
+                try:
+                    name._fail_with_undefined_error()
+                except Exception as e:
+                    msg = f"{msg} ({e}; did you forget to quote the callable name?)"
+
+            raise TemplateRuntimeError(msg)
+
+        args = [value, *(args if args is not None else ())]
+        kwargs = kwargs if kwargs is not None else {}
+        pass_arg = _PassArg.from_obj(func)
+
+        if pass_arg is _PassArg.context:
+            if context is None:
+                raise TemplateRuntimeError(
+                    f"Attempted to invoke a context {type_name} without context."
+                )
+
+            args.insert(0, context)
+        elif pass_arg is _PassArg.eval_context:
+            if eval_ctx is None:
+                if context is not None:
+                    eval_ctx = context.eval_ctx
+                else:
+                    eval_ctx = EvalContext(self)
+
+            args.insert(0, eval_ctx)
+        elif pass_arg is _PassArg.environment:
+            args.insert(0, self)
+
+        return func(*args, **kwargs)
+
+    def call_filter(
+        self,
+        name: str,
+        value: t.Any,
+        args: t.Optional[t.Sequence[t.Any]] = None,
+        kwargs: t.Optional[t.Mapping[str, t.Any]] = None,
+        context: t.Optional[Context] = None,
+        eval_ctx: t.Optional[EvalContext] = None,
+    ) -> t.Any:
+        """Invoke a filter on a value the same way the compiler does.
+
+        This might return a coroutine if the filter is running from an
+        environment in async mode and the filter supports async
+        execution. It's your responsibility to await this if needed.
+
+        .. versionadded:: 2.7
+        """
+        return self._filter_test_common(
+            name, value, args, kwargs, context, eval_ctx, True
+        )
+
+    def call_test(
+        self,
+        name: str,
+        value: t.Any,
+        args: t.Optional[t.Sequence[t.Any]] = None,
+        kwargs: t.Optional[t.Mapping[str, t.Any]] = None,
+        context: t.Optional[Context] = None,
+        eval_ctx: t.Optional[EvalContext] = None,
+    ) -> t.Any:
+        """Invoke a test on a value the same way the compiler does.
+
+        This might return a coroutine if the test is running from an
+        environment in async mode and the test supports async execution.
+        It's your responsibility to await this if needed.
+
+        .. versionchanged:: 3.0
+            Tests support ``@pass_context``, etc. decorators. Added
+            the ``context`` and ``eval_ctx`` parameters.
+
+        .. versionadded:: 2.7
+        """
+        return self._filter_test_common(
+            name, value, args, kwargs, context, eval_ctx, False
+        )
+
+    @internalcode
+    def parse(
+        self,
+        source: str,
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+    ) -> nodes.Template:
+        """Parse the sourcecode and return the abstract syntax tree.  This
+        tree of nodes is used by the compiler to convert the template into
+        executable source- or bytecode.  This is useful for debugging or to
+        extract information from templates.
+
+        If you are :ref:`developing Jinja extensions <writing-extensions>`
+        this gives you a good overview of the node tree generated.
+        """
+        try:
+            return self._parse(source, name, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source)
+
+    def _parse(
+        self, source: str, name: t.Optional[str], filename: t.Optional[str]
+    ) -> nodes.Template:
+        """Internal parsing function used by `parse` and `compile`."""
+        return Parser(self, source, name, filename).parse()
+
+    def lex(
+        self,
+        source: str,
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+    ) -> t.Iterator[t.Tuple[int, str, str]]:
+        """Lex the given sourcecode and return a generator that yields
+        tokens as tuples in the form ``(lineno, token_type, value)``.
+        This can be useful for :ref:`extension development <writing-extensions>`
+        and debugging templates.
+
+        This does not perform preprocessing.  If you want the preprocessing
+        of the extensions to be applied you have to filter source through
+        the :meth:`preprocess` method.
+        """
+        source = str(source)
+        try:
+            return self.lexer.tokeniter(source, name, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source)
+
+    def preprocess(
+        self,
+        source: str,
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+    ) -> str:
+        """Preprocesses the source with all extensions.  This is automatically
+        called for all parsing and compiling methods but *not* for :meth:`lex`
+        because there you usually only want the actual source tokenized.
+        """
+        return reduce(
+            lambda s, e: e.preprocess(s, name, filename),
+            self.iter_extensions(),
+            str(source),
+        )
+
+    def _tokenize(
+        self,
+        source: str,
+        name: t.Optional[str],
+        filename: t.Optional[str] = None,
+        state: t.Optional[str] = None,
+    ) -> TokenStream:
+        """Called by the parser to do the preprocessing and filtering
+        for all the extensions.  Returns a :class:`~jinja2.lexer.TokenStream`.
+        """
+        source = self.preprocess(source, name, filename)
+        stream = self.lexer.tokenize(source, name, filename, state)
+
+        for ext in self.iter_extensions():
+            stream = ext.filter_stream(stream)  # type: ignore
+
+            if not isinstance(stream, TokenStream):
+                stream = TokenStream(stream, name, filename)  # type: ignore
+
+        return stream
+
+    def _generate(
+        self,
+        source: nodes.Template,
+        name: t.Optional[str],
+        filename: t.Optional[str],
+        defer_init: bool = False,
+    ) -> str:
+        """Internal hook that can be overridden to hook a different generate
+        method in.
+
+        .. versionadded:: 2.5
+        """
+        return generate(  # type: ignore
+            source,
+            self,
+            name,
+            filename,
+            defer_init=defer_init,
+            optimized=self.optimized,
+        )
+
+    def _compile(self, source: str, filename: str) -> CodeType:
+        """Internal hook that can be overridden to hook a different compile
+        method in.
+
+        .. versionadded:: 2.5
+        """
+        return compile(source, filename, "exec")  # type: ignore
+
+    @typing.overload
+    def compile(  # type: ignore
+        self,
+        source: t.Union[str, nodes.Template],
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+        raw: "te.Literal[False]" = False,
+        defer_init: bool = False,
+    ) -> CodeType:
+        ...
+
+    @typing.overload
+    def compile(
+        self,
+        source: t.Union[str, nodes.Template],
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+        raw: "te.Literal[True]" = ...,
+        defer_init: bool = False,
+    ) -> str:
+        ...
+
+    @internalcode
+    def compile(
+        self,
+        source: t.Union[str, nodes.Template],
+        name: t.Optional[str] = None,
+        filename: t.Optional[str] = None,
+        raw: bool = False,
+        defer_init: bool = False,
+    ) -> t.Union[str, CodeType]:
+        """Compile a node or template source code.  The `name` parameter is
+        the load name of the template after it was joined using
+        :meth:`join_path` if necessary, not the filename on the file system.
+        the `filename` parameter is the estimated filename of the template on
+        the file system.  If the template came from a database or memory this
+        can be omitted.
+
+        The return value of this method is a python code object.  If the `raw`
+        parameter is `True` the return value will be a string with python
+        code equivalent to the bytecode returned otherwise.  This method is
+        mainly used internally.
+
+        `defer_init` is use internally to aid the module code generator.  This
+        causes the generated code to be able to import without the global
+        environment variable to be set.
+
+        .. versionadded:: 2.4
+           `defer_init` parameter added.
+        """
+        source_hint = None
+        try:
+            if isinstance(source, str):
+                source_hint = source
+                source = self._parse(source, name, filename)
+            source = self._generate(source, name, filename, defer_init=defer_init)
+            if raw:
+                return source
+            if filename is None:
+                filename = "<template>"
+            return self._compile(source, filename)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source_hint)
+
+    def compile_expression(
+        self, source: str, undefined_to_none: bool = True
+    ) -> "TemplateExpression":
+        """A handy helper method that returns a callable that accepts keyword
+        arguments that appear as variables in the expression.  If called it
+        returns the result of the expression.
+
+        This is useful if applications want to use the same rules as Jinja
+        in template "configuration files" or similar situations.
+
+        Example usage:
+
+        >>> env = Environment()
+        >>> expr = env.compile_expression('foo == 42')
+        >>> expr(foo=23)
+        False
+        >>> expr(foo=42)
+        True
+
+        Per default the return value is converted to `None` if the
+        expression returns an undefined value.  This can be changed
+        by setting `undefined_to_none` to `False`.
+
+        >>> env.compile_expression('var')() is None
+        True
+        >>> env.compile_expression('var', undefined_to_none=False)()
+        Undefined
+
+        .. versionadded:: 2.1
+        """
+        parser = Parser(self, source, state="variable")
+        try:
+            expr = parser.parse_expression()
+            if not parser.stream.eos:
+                raise TemplateSyntaxError(
+                    "chunk after expression", parser.stream.current.lineno, None, None
+                )
+            expr.set_environment(self)
+        except TemplateSyntaxError:
+            self.handle_exception(source=source)
+
+        body = [nodes.Assign(nodes.Name("result", "store"), expr, lineno=1)]
+        template = self.from_string(nodes.Template(body, lineno=1))
+        return TemplateExpression(template, undefined_to_none)
+
+    def compile_templates(
+        self,
+        target: t.Union[str, os.PathLike],
+        extensions: t.Optional[t.Collection[str]] = None,
+        filter_func: t.Optional[t.Callable[[str], bool]] = None,
+        zip: t.Optional[str] = "deflated",
+        log_function: t.Optional[t.Callable[[str], None]] = None,
+        ignore_errors: bool = True,
+    ) -> None:
+        """Finds all the templates the loader can find, compiles them
+        and stores them in `target`.  If `zip` is `None`, instead of in a
+        zipfile, the templates will be stored in a directory.
+        By default a deflate zip algorithm is used. To switch to
+        the stored algorithm, `zip` can be set to ``'stored'``.
+
+        `extensions` and `filter_func` are passed to :meth:`list_templates`.
+        Each template returned will be compiled to the target folder or
+        zipfile.
+
+        By default template compilation errors are ignored.  In case a
+        log function is provided, errors are logged.  If you want template
+        syntax errors to abort the compilation you can set `ignore_errors`
+        to `False` and you will get an exception on syntax errors.
+
+        .. versionadded:: 2.4
+        """
+        from .loaders import ModuleLoader
+
+        if log_function is None:
+
+            def log_function(x: str) -> None:
+                pass
+
+        assert log_function is not None
+        assert self.loader is not None, "No loader configured."
+
+        def write_file(filename: str, data: str) -> None:
+            if zip:
+                info = ZipInfo(filename)
+                info.external_attr = 0o755 << 16
+                zip_file.writestr(info, data)
+            else:
+                with open(os.path.join(target, filename), "wb") as f:
+                    f.write(data.encode("utf8"))
+
+        if zip is not None:
+            from zipfile import ZipFile, ZipInfo, ZIP_DEFLATED, ZIP_STORED
+
+            zip_file = ZipFile(
+                target, "w", dict(deflated=ZIP_DEFLATED, stored=ZIP_STORED)[zip]
+            )
+            log_function(f"Compiling into Zip archive {target!r}")
+        else:
+            if not os.path.isdir(target):
+                os.makedirs(target)
+            log_function(f"Compiling into folder {target!r}")
+
+        try:
+            for name in self.list_templates(extensions, filter_func):
+                source, filename, _ = self.loader.get_source(self, name)
+                try:
+                    code = self.compile(source, name, filename, True, True)
+                except TemplateSyntaxError as e:
+                    if not ignore_errors:
+                        raise
+                    log_function(f'Could not compile "{name}": {e}')
+                    continue
+
+                filename = ModuleLoader.get_module_filename(name)
+
+                write_file(filename, code)
+                log_function(f'Compiled "{name}" as {filename}')
+        finally:
+            if zip:
+                zip_file.close()
+
+        log_function("Finished compiling templates")
+
+    def list_templates(
+        self,
+        extensions: t.Optional[t.Collection[str]] = None,
+        filter_func: t.Optional[t.Callable[[str], bool]] = None,
+    ) -> t.List[str]:
+        """Returns a list of templates for this environment.  This requires
+        that the loader supports the loader's
+        :meth:`~BaseLoader.list_templates` method.
+
+        If there are other files in the template folder besides the
+        actual templates, the returned list can be filtered.  There are two
+        ways: either `extensions` is set to a list of file extensions for
+        templates, or a `filter_func` can be provided which is a callable that
+        is passed a template name and should return `True` if it should end up
+        in the result list.
+
+        If the loader does not support that, a :exc:`TypeError` is raised.
+
+        .. versionadded:: 2.4
+        """
+        assert self.loader is not None, "No loader configured."
+        names = self.loader.list_templates()
+
+        if extensions is not None:
+            if filter_func is not None:
+                raise TypeError(
+                    "either extensions or filter_func can be passed, but not both"
+                )
+
+            def filter_func(x: str) -> bool:
+                return "." in x and x.rsplit(".", 1)[1] in extensions  # type: ignore
+
+        if filter_func is not None:
+            names = [name for name in names if filter_func(name)]
+
+        return names
+
+    def handle_exception(self, source: t.Optional[str] = None) -> "te.NoReturn":
+        """Exception handling helper.  This is used internally to either raise
+        rewritten exceptions or return a rendered traceback for the template.
+        """
+        from .debug import rewrite_traceback_stack
+
+        raise rewrite_traceback_stack(source=source)
+
+    def join_path(self, template: str, parent: str) -> str:
+        """Join a template with the parent.  By default all the lookups are
+        relative to the loader root so this method returns the `template`
+        parameter unchanged, but if the paths should be relative to the
+        parent template, this function can be used to calculate the real
+        template name.
+
+        Subclasses may override this method and implement template path
+        joining here.
+        """
+        return template
+
+    @internalcode
+    def _load_template(
+        self, name: str, globals: t.Optional[t.MutableMapping[str, t.Any]]
+    ) -> "Template":
+        if self.loader is None:
+            raise TypeError("no loader for this environment specified")
+        cache_key = (weakref.ref(self.loader), name)
+        if self.cache is not None:
+            template = self.cache.get(cache_key)
+            if template is not None and (
+                not self.auto_reload or template.is_up_to_date
+            ):
+                # template.globals is a ChainMap, modifying it will only
+                # affect the template, not the environment globals.
+                if globals:
+                    template.globals.update(globals)
+
+                return template
+
+        template = self.loader.load(self, name, self.make_globals(globals))
+
+        if self.cache is not None:
+            self.cache[cache_key] = template
+        return template
+
+    @internalcode
+    def get_template(
+        self,
+        name: t.Union[str, "Template"],
+        parent: t.Optional[str] = None,
+        globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
+    ) -> "Template":
+        """Load a template by name with :attr:`loader` and return a
+        :class:`Template`. If the template does not exist a
+        :exc:`TemplateNotFound` exception is raised.
+
+        :param name: Name of the template to load. When loading
+            templates from the filesystem, "/" is used as the path
+            separator, even on Windows.
+        :param parent: The name of the parent template importing this
+            template. :meth:`join_path` can be used to implement name
+            transformations with this.
+        :param globals: Extend the environment :attr:`globals` with
+            these extra variables available for all renders of this
+            template. If the template has already been loaded and
+            cached, its globals are updated with any new items.
+
+        .. versionchanged:: 3.0
+            If a template is loaded from cache, ``globals`` will update
+            the template's globals instead of ignoring the new values.
+
+        .. versionchanged:: 2.4
+            If ``name`` is a :class:`Template` object it is returned
+            unchanged.
+        """
+        if isinstance(name, Template):
+            return name
+        if parent is not None:
+            name = self.join_path(name, parent)
+
+        return self._load_template(name, globals)
+
+    @internalcode
+    def select_template(
+        self,
+        names: t.Iterable[t.Union[str, "Template"]],
+        parent: t.Optional[str] = None,
+        globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
+    ) -> "Template":
+        """Like :meth:`get_template`, but tries loading multiple names.
+        If none of the names can be loaded a :exc:`TemplatesNotFound`
+        exception is raised.
+
+        :param names: List of template names to try loading in order.
+        :param parent: The name of the parent template importing this
+            template. :meth:`join_path` can be used to implement name
+            transformations with this.
+        :param globals: Extend the environment :attr:`globals` with
+            these extra variables available for all renders of this
+            template. If the template has already been loaded and
+            cached, its globals are updated with any new items.
+
+        .. versionchanged:: 3.0
+            If a template is loaded from cache, ``globals`` will update
+            the template's globals instead of ignoring the new values.
+
+        .. versionchanged:: 2.11
+            If ``names`` is :class:`Undefined`, an :exc:`UndefinedError`
+            is raised instead. If no templates were found and ``names``
+            contains :class:`Undefined`, the message is more helpful.
+
+        .. versionchanged:: 2.4
+            If ``names`` contains a :class:`Template` object it is
+            returned unchanged.
+
+        .. versionadded:: 2.3
+        """
+        if isinstance(names, Undefined):
+            names._fail_with_undefined_error()
+
+        if not names:
+            raise TemplatesNotFound(
+                message="Tried to select from an empty list of templates."
+            )
+
+        for name in names:
+            if isinstance(name, Template):
+                return name
+            if parent is not None:
+                name = self.join_path(name, parent)
+            try:
+                return self._load_template(name, globals)
+            except (TemplateNotFound, UndefinedError):
+                pass
+        raise TemplatesNotFound(names)  # type: ignore
+
+    @internalcode
+    def get_or_select_template(
+        self,
+        template_name_or_list: t.Union[
+            str, "Template", t.List[t.Union[str, "Template"]]
+        ],
+        parent: t.Optional[str] = None,
+        globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
+    ) -> "Template":
+        """Use :meth:`select_template` if an iterable of template names
+        is given, or :meth:`get_template` if one name is given.
+
+        .. versionadded:: 2.3
+        """
+        if isinstance(template_name_or_list, (str, Undefined)):
+            return self.get_template(template_name_or_list, parent, globals)
+        elif isinstance(template_name_or_list, Template):
+            return template_name_or_list
+        return self.select_template(template_name_or_list, parent, globals)
+
+    def from_string(
+        self,
+        source: t.Union[str, nodes.Template],
+        globals: t.Optional[t.MutableMapping[str, t.Any]] = None,
+        template_class: t.Optional[t.Type["Template"]] = None,
+    ) -> "Template":
+        """Load a template from a source string without using
+        :attr:`loader`.
+
+        :param source: Jinja source to compile into a template.
+        :param globals: Extend the environment :attr:`globals` with
+            these extra variables available for all renders of this
+            template. If the template has already been loaded and
+            cached, its globals are updated with any new items.
+        :param template_class: Return an instance of this
+            :class:`Template` class.
+        """
+        gs = self.make_globals(globals)
+        cls = template_class or self.template_class
+        return cls.from_code(self, self.compile(source), gs, None)
+
+    def make_globals(
+        self, d: t.Optional[t.MutableMapping[str, t.Any]]
+    ) -> t.MutableMapping[str, t.Any]:
+        """Make the globals map for a template. Any given template
+        globals overlay the environment :attr:`globals`.
+
+        Returns a :class:`collections.ChainMap`. This allows any changes
+        to a template's globals to only affect that template, while
+        changes to the environment's globals are still reflected.
+        However, avoid modifying any globals after a template is loaded.
+
+        :param d: Dict of template-specific globals.
+
+        .. versionchanged:: 3.0
+            Use :class:`collections.ChainMap` to always prevent mutating
+            environment globals.
+        """
+        if d is None:
+            d = {}
+
+        return ChainMap(d, self.globals)
+
+
+class Template:
+    """A compiled template that can be rendered.
+
+    Use the methods on :class:`Environment` to create or load templates.
+    The environment is used to configure how templates are compiled and
+    behave.
+
+    It is also possible to create a template object directly. This is
+    not usually recommended. The constructor takes most of the same
+    arguments as :class:`Environment`. All templates created with the
+    same environment arguments share the same ephemeral ``Environment``
+    instance behind the scenes.
+
+    A template object should be considered immutable. Modifications on
+    the object are not supported.
+    """
+
+    #: Type of environment to create when creating a template directly
+    #: rather than through an existing environment.
+    environment_class: t.Type[Environment] = Environment
+
+    environment: Environment
+    globals: t.MutableMapping[str, t.Any]
+    name: t.Optional[str]
+    filename: t.Optional[str]
+    blocks: t.Dict[str, t.Callable[[Context], t.Iterator[str]]]
+    root_render_func: t.Callable[[Context], t.Iterator[str]]
+    _module: t.Optional["TemplateModule"]
+    _debug_info: str
+    _uptodate: t.Optional[t.Callable[[], bool]]
+
+    def __new__(
+        cls,
+        source: t.Union[str, nodes.Template],
+        block_start_string: str = BLOCK_START_STRING,
+        block_end_string: str = BLOCK_END_STRING,
+        variable_start_string: str = VARIABLE_START_STRING,
+        variable_end_string: str = VARIABLE_END_STRING,
+        comment_start_string: str = COMMENT_START_STRING,
+        comment_end_string: str = COMMENT_END_STRING,
+        line_statement_prefix: t.Optional[str] = LINE_STATEMENT_PREFIX,
+        line_comment_prefix: t.Optional[str] = LINE_COMMENT_PREFIX,
+        trim_blocks: bool = TRIM_BLOCKS,
+        lstrip_blocks: bool = LSTRIP_BLOCKS,
+        newline_sequence: "te.Literal['\\n', '\\r\\n', '\\r']" = NEWLINE_SEQUENCE,
+        keep_trailing_newline: bool = KEEP_TRAILING_NEWLINE,
+        extensions: t.Sequence[t.Union[str, t.Type["Extension"]]] = (),
+        optimized: bool = True,
+        undefined: t.Type[Undefined] = Undefined,
+        finalize: t.Optional[t.Callable[..., t.Any]] = None,
+        autoescape: t.Union[bool, t.Callable[[t.Optional[str]], bool]] = False,
+        enable_async: bool = False,
+    ) -> t.Any:  # it returns a `Template`, but this breaks the sphinx build...
+        env = get_spontaneous_environment(
+            cls.environment_class,  # type: ignore
+            block_start_string,
+            block_end_string,
+            variable_start_string,
+            variable_end_string,
+            comment_start_string,
+            comment_end_string,
+            line_statement_prefix,
+            line_comment_prefix,
+            trim_blocks,
+            lstrip_blocks,
+            newline_sequence,
+            keep_trailing_newline,
+            frozenset(extensions),
+            optimized,
+            undefined,  # type: ignore
+            finalize,
+            autoescape,
+            None,
+            0,
+            False,
+            None,
+            enable_async,
+        )
+        return env.from_string(source, template_class=cls)
+
+    @classmethod
+    def from_code(
+        cls,
+        environment: Environment,
+        code: CodeType,
+        globals: t.MutableMapping[str, t.Any],
+        uptodate: t.Optional[t.Callable[[], bool]] = None,
+    ) -> "Template":
+        """Creates a template object from compiled code and the globals.  This
+        is used by the loaders and environment to create a template object.
+        """
+        namespace = {"environment": environment, "__file__": code.co_filename}
+        exec(code, namespace)
+        rv = cls._from_namespace(environment, namespace, globals)
+        rv._uptodate = uptodate
+        return rv
+
+    @classmethod
+    def from_module_dict(
+        cls,
+        environment: Environment,
+        module_dict: t.MutableMapping[str, t.Any],
+        globals: t.MutableMapping[str, t.Any],
+    ) -> "Template":
+        """Creates a template object from a module.  This is used by the
+        module loader to create a template object.
+
+        .. versionadded:: 2.4
+        """
+        return cls._from_namespace(environment, module_dict, globals)
+
+    @classmethod
+    def _from_namespace(
+        cls,
+        environment: Environment,
+        namespace: t.MutableMapping[str, t.Any],
+        globals: t.MutableMapping[str, t.Any],
+    ) -> "Template":
+        t: "Template" = object.__new__(cls)
+        t.environment = environment
+        t.globals = globals
+        t.name = namespace["name"]
+        t.filename = namespace["__file__"]
+        t.blocks = namespace["blocks"]
+
+        # render function and module
+        t.root_render_func = namespace["root"]  # type: ignore
+        t._module = None
+
+        # debug and loader helpers
+        t._debug_info = namespace["debug_info"]
+        t._uptodate = None
+
+        # store the reference
+        namespace["environment"] = environment
+        namespace["__jinja_template__"] = t
+
+        return t
+
+    def render(self, *args: t.Any, **kwargs: t.Any) -> str:
+        """This method accepts the same arguments as the `dict` constructor:
+        A dict, a dict subclass or some keyword arguments.  If no arguments
+        are given the context will be empty.  These two calls do the same::
+
+            template.render(knights='that say nih')
+            template.render({'knights': 'that say nih'})
+
+        This will return the rendered template as a string.
+        """
+        if self.environment.is_async:
+            import asyncio
+
+            close = False
+
+            try:
+                loop = asyncio.get_running_loop()
+            except RuntimeError:
+                loop = asyncio.new_event_loop()
+                close = True
+
+            try:
+                return loop.run_until_complete(self.render_async(*args, **kwargs))
+            finally:
+                if close:
+                    loop.close()
+
+        ctx = self.new_context(dict(*args, **kwargs))
+
+        try:
+            return self.environment.concat(self.root_render_func(ctx))  # type: ignore
+        except Exception:
+            self.environment.handle_exception()
+
+    async def render_async(self, *args: t.Any, **kwargs: t.Any) -> str:
+        """This works similar to :meth:`render` but returns a coroutine
+        that when awaited returns the entire rendered template string.  This
+        requires the async feature to be enabled.
+
+        Example usage::
+
+            await template.render_async(knights='that say nih; asynchronously')
+        """
+        if not self.environment.is_async:
+            raise RuntimeError(
+                "The environment was not created with async mode enabled."
+            )
+
+        ctx = self.new_context(dict(*args, **kwargs))
+
+        try:
+            return self.environment.concat(  # type: ignore
+                [n async for n in self.root_render_func(ctx)]  # type: ignore
+            )
+        except Exception:
+            return self.environment.handle_exception()
+
+    def stream(self, *args: t.Any, **kwargs: t.Any) -> "TemplateStream":
+        """Works exactly like :meth:`generate` but returns a
+        :class:`TemplateStream`.
+        """
+        return TemplateStream(self.generate(*args, **kwargs))
+
+    def generate(self, *args: t.Any, **kwargs: t.Any) -> t.Iterator[str]:
+        """For very large templates it can be useful to not render the whole
+        template at once but evaluate each statement after another and yield
+        piece for piece.  This method basically does exactly that and returns
+        a generator that yields one item after another as strings.
+
+        It accepts the same arguments as :meth:`render`.
+        """
+        if self.environment.is_async:
+            import asyncio
+
+            async def to_list() -> t.List[str]:
+                return [x async for x in self.generate_async(*args, **kwargs)]
+
+            yield from asyncio.run(to_list())
+            return
+
+        ctx = self.new_context(dict(*args, **kwargs))
+
+        try:
+            yield from self.root_render_func(ctx)  # type: ignore
+        except Exception:
+            yield self.environment.handle_exception()
+
+    async def generate_async(
+        self, *args: t.Any, **kwargs: t.Any
+    ) -> t.AsyncIterator[str]:
+        """An async version of :meth:`generate`.  Works very similarly but
+        returns an async iterator instead.
+        """
+        if not self.environment.is_async:
+            raise RuntimeError(
+                "The environment was not created with async mode enabled."
+            )
+
+        ctx = self.new_context(dict(*args, **kwargs))
+
+        try:
+            async for event in self.root_render_func(ctx):  # type: ignore
+                yield event
+        except Exception:
+            yield self.environment.handle_exception()
+
+    def new_context(
+        self,
+        vars: t.Optional[t.Dict[str, t.Any]] = None,
+        shared: bool = False,
+        locals: t.Optional[t.Mapping[str, t.Any]] = None,
+    ) -> Context:
+        """Create a new :class:`Context` for this template.  The vars
+        provided will be passed to the template.  Per default the globals
+        are added to the context.  If shared is set to `True` the data
+        is passed as is to the context without adding the globals.
+
+        `locals` can be a dict of local variables for internal usage.
+        """
+        return new_context(
+            self.environment, self.name, self.blocks, vars, shared, self.globals, locals
+        )
+
+    def make_module(
+        self,
+        vars: t.Optional[t.Dict[str, t.Any]] = None,
+        shared: bool = False,
+        locals: t.Optional[t.Mapping[str, t.Any]] = None,
+    ) -> "TemplateModule":
+        """This method works like the :attr:`module` attribute when called
+        without arguments but it will evaluate the template on every call
+        rather than caching it.  It's also possible to provide
+        a dict which is then used as context.  The arguments are the same
+        as for the :meth:`new_context` method.
+        """
+        ctx = self.new_context(vars, shared, locals)
+        return TemplateModule(self, ctx)
+
+    async def make_module_async(
+        self,
+        vars: t.Optional[t.Dict[str, t.Any]] = None,
+        shared: bool = False,
+        locals: t.Optional[t.Mapping[str, t.Any]] = None,
+    ) -> "TemplateModule":
+        """As template module creation can invoke template code for
+        asynchronous executions this method must be used instead of the
+        normal :meth:`make_module` one.  Likewise the module attribute
+        becomes unavailable in async mode.
+        """
+        ctx = self.new_context(vars, shared, locals)
+        return TemplateModule(
+            self, ctx, [x async for x in self.root_render_func(ctx)]  # type: ignore
+        )
+
+    @internalcode
+    def _get_default_module(self, ctx: t.Optional[Context] = None) -> "TemplateModule":
+        """If a context is passed in, this means that the template was
+        imported. Imported templates have access to the current
+        template's globals by default, but they can only be accessed via
+        the context during runtime.
+
+        If there are new globals, we need to create a new module because
+        the cached module is already rendered and will not have access
+        to globals from the current context. This new module is not
+        cached because the template can be imported elsewhere, and it
+        should have access to only the current template's globals.
+        """
+        if self.environment.is_async:
+            raise RuntimeError("Module is not available in async mode.")
+
+        if ctx is not None:
+            keys = ctx.globals_keys - self.globals.keys()
+
+            if keys:
+                return self.make_module({k: ctx.parent[k] for k in keys})
+
+        if self._module is None:
+            self._module = self.make_module()
+
+        return self._module
+
+    async def _get_default_module_async(
+        self, ctx: t.Optional[Context] = None
+    ) -> "TemplateModule":
+        if ctx is not None:
+            keys = ctx.globals_keys - self.globals.keys()
+
+            if keys:
+                return await self.make_module_async({k: ctx.parent[k] for k in keys})
+
+        if self._module is None:
+            self._module = await self.make_module_async()
+
+        return self._module
+
+    @property
+    def module(self) -> "TemplateModule":
+        """The template as module.  This is used for imports in the
+        template runtime but is also useful if one wants to access
+        exported template variables from the Python layer:
+
+        >>> t = Template('{% macro foo() %}42{% endmacro %}23')
+        >>> str(t.module)
+        '23'
+        >>> t.module.foo() == u'42'
+        True
+
+        This attribute is not available if async mode is enabled.
+        """
+        return self._get_default_module()
+
+    def get_corresponding_lineno(self, lineno: int) -> int:
+        """Return the source line number of a line number in the
+        generated bytecode as they are not in sync.
+        """
+        for template_line, code_line in reversed(self.debug_info):
+            if code_line <= lineno:
+                return template_line
+        return 1
+
+    @property
+    def is_up_to_date(self) -> bool:
+        """If this variable is `False` there is a newer version available."""
+        if self._uptodate is None:
+            return True
+        return self._uptodate()
+
+    @property
+    def debug_info(self) -> t.List[t.Tuple[int, int]]:
+        """The debug info mapping."""
+        if self._debug_info:
+            return [
+                tuple(map(int, x.split("=")))  # type: ignore
+                for x in self._debug_info.split("&")
+            ]
+
+        return []
+
+    def __repr__(self) -> str:
+        if self.name is None:
+            name = f"memory:{id(self):x}"
+        else:
+            name = repr(self.name)
+        return f"<{type(self).__name__} {name}>"
+
+
+class TemplateModule:
+    """Represents an imported template.  All the exported names of the
+    template are available as attributes on this object.  Additionally
+    converting it into a string renders the contents.
+    """
+
+    def __init__(
+        self,
+        template: Template,
+        context: Context,
+        body_stream: t.Optional[t.Iterable[str]] = None,
+    ) -> None:
+        if body_stream is None:
+            if context.environment.is_async:
+                raise RuntimeError(
+                    "Async mode requires a body stream to be passed to"
+                    " a template module. Use the async methods of the"
+                    " API you are using."
+                )
+
+            body_stream = list(template.root_render_func(context))  # type: ignore
+
+        self._body_stream = body_stream
+        self.__dict__.update(context.get_exported())
+        self.__name__ = template.name
+
+    def __html__(self) -> Markup:
+        return Markup(concat(self._body_stream))
+
+    def __str__(self) -> str:
+        return concat(self._body_stream)
+
+    def __repr__(self) -> str:
+        if self.__name__ is None:
+            name = f"memory:{id(self):x}"
+        else:
+            name = repr(self.__name__)
+        return f"<{type(self).__name__} {name}>"
+
+
+class TemplateExpression:
+    """The :meth:`jinja2.Environment.compile_expression` method returns an
+    instance of this object.  It encapsulates the expression-like access
+    to the template with an expression it wraps.
+    """
+
+    def __init__(self, template: Template, undefined_to_none: bool) -> None:
+        self._template = template
+        self._undefined_to_none = undefined_to_none
+
+    def __call__(self, *args: t.Any, **kwargs: t.Any) -> t.Optional[t.Any]:
+        context = self._template.new_context(dict(*args, **kwargs))
+        consume(self._template.root_render_func(context))  # type: ignore
+        rv = context.vars["result"]
+        if self._undefined_to_none and isinstance(rv, Undefined):
+            rv = None
+        return rv
+
+
+class TemplateStream:
+    """A template stream works pretty much like an ordinary python generator
+    but it can buffer multiple items to reduce the number of total iterations.
+    Per default the output is unbuffered which means that for every unbuffered
+    instruction in the template one string is yielded.
+
+    If buffering is enabled with a buffer size of 5, five items are combined
+    into a new string.  This is mainly useful if you are streaming
+    big templates to a client via WSGI which flushes after each iteration.
+    """
+
+    def __init__(self, gen: t.Iterator[str]) -> None:
+        self._gen = gen
+        self.disable_buffering()
+
+    def dump(
+        self,
+        fp: t.Union[str, t.IO],
+        encoding: t.Optional[str] = None,
+        errors: t.Optional[str] = "strict",
+    ) -> None:
+        """Dump the complete stream into a file or file-like object.
+        Per default strings are written, if you want to encode
+        before writing specify an `encoding`.
+
+        Example usage::
+
+            Template('Hello {{ name }}!').stream(name='foo').dump('hello.html')
+        """
+        close = False
+
+        if isinstance(fp, str):
+            if encoding is None:
+                encoding = "utf-8"
+
+            fp = open(fp, "wb")
+            close = True
+        try:
+            if encoding is not None:
+                iterable = (x.encode(encoding, errors) for x in self)  # type: ignore
+            else:
+                iterable = self  # type: ignore
+
+            if hasattr(fp, "writelines"):
+                fp.writelines(iterable)
+            else:
+                for item in iterable:
+                    fp.write(item)
+        finally:
+            if close:
+                fp.close()
+
+    def disable_buffering(self) -> None:
+        """Disable the output buffering."""
+        self._next = partial(next, self._gen)
+        self.buffered = False
+
+    def _buffered_generator(self, size: int) -> t.Iterator[str]:
+        buf: t.List[str] = []
+        c_size = 0
+        push = buf.append
+
+        while True:
+            try:
+                while c_size < size:
+                    c = next(self._gen)
+                    push(c)
+                    if c:
+                        c_size += 1
+            except StopIteration:
+                if not c_size:
+                    return
+            yield concat(buf)
+            del buf[:]
+            c_size = 0
+
+    def enable_buffering(self, size: int = 5) -> None:
+        """Enable buffering.  Buffer `size` items before yielding them."""
+        if size <= 1:
+            raise ValueError("buffer size too small")
+
+        self.buffered = True
+        self._next = partial(next, self._buffered_generator(size))
+
+    def __iter__(self) -> "TemplateStream":
+        return self
+
+    def __next__(self) -> str:
+        return self._next()  # type: ignore
+
+
+# hook in default template class.  if anyone reads this comment: ignore that
+# it's possible to use custom templates ;-)
+Environment.template_class = Template