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-rw-r--r--src/jinja2/parser.py1032
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diff --git a/src/jinja2/parser.py b/src/jinja2/parser.py
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+++ b/src/jinja2/parser.py
@@ -0,0 +1,1032 @@
+"""Parse tokens from the lexer into nodes for the compiler."""
+import typing
+import typing as t
+
+from . import nodes
+from .exceptions import TemplateAssertionError
+from .exceptions import TemplateSyntaxError
+from .lexer import describe_token
+from .lexer import describe_token_expr
+
+if t.TYPE_CHECKING:
+ import typing_extensions as te
+ from .environment import Environment
+
+_ImportInclude = t.TypeVar("_ImportInclude", nodes.Import, nodes.Include)
+_MacroCall = t.TypeVar("_MacroCall", nodes.Macro, nodes.CallBlock)
+
+_statement_keywords = frozenset(
+ [
+ "for",
+ "if",
+ "block",
+ "extends",
+ "print",
+ "macro",
+ "include",
+ "from",
+ "import",
+ "set",
+ "with",
+ "autoescape",
+ ]
+)
+_compare_operators = frozenset(["eq", "ne", "lt", "lteq", "gt", "gteq"])
+
+_math_nodes: t.Dict[str, t.Type[nodes.Expr]] = {
+ "add": nodes.Add,
+ "sub": nodes.Sub,
+ "mul": nodes.Mul,
+ "div": nodes.Div,
+ "floordiv": nodes.FloorDiv,
+ "mod": nodes.Mod,
+}
+
+
+class Parser:
+ """This is the central parsing class Jinja uses. It's passed to
+ extensions and can be used to parse expressions or statements.
+ """
+
+ def __init__(
+ self,
+ environment: "Environment",
+ source: str,
+ name: t.Optional[str] = None,
+ filename: t.Optional[str] = None,
+ state: t.Optional[str] = None,
+ ) -> None:
+ self.environment = environment
+ self.stream = environment._tokenize(source, name, filename, state)
+ self.name = name
+ self.filename = filename
+ self.closed = False
+ self.extensions: t.Dict[
+ str, t.Callable[["Parser"], t.Union[nodes.Node, t.List[nodes.Node]]]
+ ] = {}
+ for extension in environment.iter_extensions():
+ for tag in extension.tags:
+ self.extensions[tag] = extension.parse
+ self._last_identifier = 0
+ self._tag_stack: t.List[str] = []
+ self._end_token_stack: t.List[t.Tuple[str, ...]] = []
+
+ def fail(
+ self,
+ msg: str,
+ lineno: t.Optional[int] = None,
+ exc: t.Type[TemplateSyntaxError] = TemplateSyntaxError,
+ ) -> "te.NoReturn":
+ """Convenience method that raises `exc` with the message, passed
+ line number or last line number as well as the current name and
+ filename.
+ """
+ if lineno is None:
+ lineno = self.stream.current.lineno
+ raise exc(msg, lineno, self.name, self.filename)
+
+ def _fail_ut_eof(
+ self,
+ name: t.Optional[str],
+ end_token_stack: t.List[t.Tuple[str, ...]],
+ lineno: t.Optional[int],
+ ) -> "te.NoReturn":
+ expected: t.Set[str] = set()
+ for exprs in end_token_stack:
+ expected.update(map(describe_token_expr, exprs))
+ if end_token_stack:
+ currently_looking: t.Optional[str] = " or ".join(
+ map(repr, map(describe_token_expr, end_token_stack[-1]))
+ )
+ else:
+ currently_looking = None
+
+ if name is None:
+ message = ["Unexpected end of template."]
+ else:
+ message = [f"Encountered unknown tag {name!r}."]
+
+ if currently_looking:
+ if name is not None and name in expected:
+ message.append(
+ "You probably made a nesting mistake. Jinja is expecting this tag,"
+ f" but currently looking for {currently_looking}."
+ )
+ else:
+ message.append(
+ f"Jinja was looking for the following tags: {currently_looking}."
+ )
+
+ if self._tag_stack:
+ message.append(
+ "The innermost block that needs to be closed is"
+ f" {self._tag_stack[-1]!r}."
+ )
+
+ self.fail(" ".join(message), lineno)
+
+ def fail_unknown_tag(
+ self, name: str, lineno: t.Optional[int] = None
+ ) -> "te.NoReturn":
+ """Called if the parser encounters an unknown tag. Tries to fail
+ with a human readable error message that could help to identify
+ the problem.
+ """
+ self._fail_ut_eof(name, self._end_token_stack, lineno)
+
+ def fail_eof(
+ self,
+ end_tokens: t.Optional[t.Tuple[str, ...]] = None,
+ lineno: t.Optional[int] = None,
+ ) -> "te.NoReturn":
+ """Like fail_unknown_tag but for end of template situations."""
+ stack = list(self._end_token_stack)
+ if end_tokens is not None:
+ stack.append(end_tokens)
+ self._fail_ut_eof(None, stack, lineno)
+
+ def is_tuple_end(
+ self, extra_end_rules: t.Optional[t.Tuple[str, ...]] = None
+ ) -> bool:
+ """Are we at the end of a tuple?"""
+ if self.stream.current.type in ("variable_end", "block_end", "rparen"):
+ return True
+ elif extra_end_rules is not None:
+ return self.stream.current.test_any(extra_end_rules) # type: ignore
+ return False
+
+ def free_identifier(self, lineno: t.Optional[int] = None) -> nodes.InternalName:
+ """Return a new free identifier as :class:`~jinja2.nodes.InternalName`."""
+ self._last_identifier += 1
+ rv = object.__new__(nodes.InternalName)
+ nodes.Node.__init__(rv, f"fi{self._last_identifier}", lineno=lineno)
+ return rv
+
+ def parse_statement(self) -> t.Union[nodes.Node, t.List[nodes.Node]]:
+ """Parse a single statement."""
+ token = self.stream.current
+ if token.type != "name":
+ self.fail("tag name expected", token.lineno)
+ self._tag_stack.append(token.value)
+ pop_tag = True
+ try:
+ if token.value in _statement_keywords:
+ f = getattr(self, f"parse_{self.stream.current.value}")
+ return f() # type: ignore
+ if token.value == "call":
+ return self.parse_call_block()
+ if token.value == "filter":
+ return self.parse_filter_block()
+ ext = self.extensions.get(token.value)
+ if ext is not None:
+ return ext(self)
+
+ # did not work out, remove the token we pushed by accident
+ # from the stack so that the unknown tag fail function can
+ # produce a proper error message.
+ self._tag_stack.pop()
+ pop_tag = False
+ self.fail_unknown_tag(token.value, token.lineno)
+ finally:
+ if pop_tag:
+ self._tag_stack.pop()
+
+ def parse_statements(
+ self, end_tokens: t.Tuple[str, ...], drop_needle: bool = False
+ ) -> t.List[nodes.Node]:
+ """Parse multiple statements into a list until one of the end tokens
+ is reached. This is used to parse the body of statements as it also
+ parses template data if appropriate. The parser checks first if the
+ current token is a colon and skips it if there is one. Then it checks
+ for the block end and parses until if one of the `end_tokens` is
+ reached. Per default the active token in the stream at the end of
+ the call is the matched end token. If this is not wanted `drop_needle`
+ can be set to `True` and the end token is removed.
+ """
+ # the first token may be a colon for python compatibility
+ self.stream.skip_if("colon")
+
+ # in the future it would be possible to add whole code sections
+ # by adding some sort of end of statement token and parsing those here.
+ self.stream.expect("block_end")
+ result = self.subparse(end_tokens)
+
+ # we reached the end of the template too early, the subparser
+ # does not check for this, so we do that now
+ if self.stream.current.type == "eof":
+ self.fail_eof(end_tokens)
+
+ if drop_needle:
+ next(self.stream)
+ return result
+
+ def parse_set(self) -> t.Union[nodes.Assign, nodes.AssignBlock]:
+ """Parse an assign statement."""
+ lineno = next(self.stream).lineno
+ target = self.parse_assign_target(with_namespace=True)
+ if self.stream.skip_if("assign"):
+ expr = self.parse_tuple()
+ return nodes.Assign(target, expr, lineno=lineno)
+ filter_node = self.parse_filter(None)
+ body = self.parse_statements(("name:endset",), drop_needle=True)
+ return nodes.AssignBlock(target, filter_node, body, lineno=lineno)
+
+ def parse_for(self) -> nodes.For:
+ """Parse a for loop."""
+ lineno = self.stream.expect("name:for").lineno
+ target = self.parse_assign_target(extra_end_rules=("name:in",))
+ self.stream.expect("name:in")
+ iter = self.parse_tuple(
+ with_condexpr=False, extra_end_rules=("name:recursive",)
+ )
+ test = None
+ if self.stream.skip_if("name:if"):
+ test = self.parse_expression()
+ recursive = self.stream.skip_if("name:recursive")
+ body = self.parse_statements(("name:endfor", "name:else"))
+ if next(self.stream).value == "endfor":
+ else_ = []
+ else:
+ else_ = self.parse_statements(("name:endfor",), drop_needle=True)
+ return nodes.For(target, iter, body, else_, test, recursive, lineno=lineno)
+
+ def parse_if(self) -> nodes.If:
+ """Parse an if construct."""
+ node = result = nodes.If(lineno=self.stream.expect("name:if").lineno)
+ while True:
+ node.test = self.parse_tuple(with_condexpr=False)
+ node.body = self.parse_statements(("name:elif", "name:else", "name:endif"))
+ node.elif_ = []
+ node.else_ = []
+ token = next(self.stream)
+ if token.test("name:elif"):
+ node = nodes.If(lineno=self.stream.current.lineno)
+ result.elif_.append(node)
+ continue
+ elif token.test("name:else"):
+ result.else_ = self.parse_statements(("name:endif",), drop_needle=True)
+ break
+ return result
+
+ def parse_with(self) -> nodes.With:
+ node = nodes.With(lineno=next(self.stream).lineno)
+ targets: t.List[nodes.Expr] = []
+ values: t.List[nodes.Expr] = []
+ while self.stream.current.type != "block_end":
+ if targets:
+ self.stream.expect("comma")
+ target = self.parse_assign_target()
+ target.set_ctx("param")
+ targets.append(target)
+ self.stream.expect("assign")
+ values.append(self.parse_expression())
+ node.targets = targets
+ node.values = values
+ node.body = self.parse_statements(("name:endwith",), drop_needle=True)
+ return node
+
+ def parse_autoescape(self) -> nodes.Scope:
+ node = nodes.ScopedEvalContextModifier(lineno=next(self.stream).lineno)
+ node.options = [nodes.Keyword("autoescape", self.parse_expression())]
+ node.body = self.parse_statements(("name:endautoescape",), drop_needle=True)
+ return nodes.Scope([node])
+
+ def parse_block(self) -> nodes.Block:
+ node = nodes.Block(lineno=next(self.stream).lineno)
+ node.name = self.stream.expect("name").value
+ node.scoped = self.stream.skip_if("name:scoped")
+ node.required = self.stream.skip_if("name:required")
+
+ # common problem people encounter when switching from django
+ # to jinja. we do not support hyphens in block names, so let's
+ # raise a nicer error message in that case.
+ if self.stream.current.type == "sub":
+ self.fail(
+ "Block names in Jinja have to be valid Python identifiers and may not"
+ " contain hyphens, use an underscore instead."
+ )
+
+ node.body = self.parse_statements(("name:endblock",), drop_needle=True)
+
+ # enforce that required blocks only contain whitespace or comments
+ # by asserting that the body, if not empty, is just TemplateData nodes
+ # with whitespace data
+ if node.required and not all(
+ isinstance(child, nodes.TemplateData) and child.data.isspace()
+ for body in node.body
+ for child in body.nodes # type: ignore
+ ):
+ self.fail("Required blocks can only contain comments or whitespace")
+
+ self.stream.skip_if("name:" + node.name)
+ return node
+
+ def parse_extends(self) -> nodes.Extends:
+ node = nodes.Extends(lineno=next(self.stream).lineno)
+ node.template = self.parse_expression()
+ return node
+
+ def parse_import_context(
+ self, node: _ImportInclude, default: bool
+ ) -> _ImportInclude:
+ if self.stream.current.test_any(
+ "name:with", "name:without"
+ ) and self.stream.look().test("name:context"):
+ node.with_context = next(self.stream).value == "with"
+ self.stream.skip()
+ else:
+ node.with_context = default
+ return node
+
+ def parse_include(self) -> nodes.Include:
+ node = nodes.Include(lineno=next(self.stream).lineno)
+ node.template = self.parse_expression()
+ if self.stream.current.test("name:ignore") and self.stream.look().test(
+ "name:missing"
+ ):
+ node.ignore_missing = True
+ self.stream.skip(2)
+ else:
+ node.ignore_missing = False
+ return self.parse_import_context(node, True)
+
+ def parse_import(self) -> nodes.Import:
+ node = nodes.Import(lineno=next(self.stream).lineno)
+ node.template = self.parse_expression()
+ self.stream.expect("name:as")
+ node.target = self.parse_assign_target(name_only=True).name
+ return self.parse_import_context(node, False)
+
+ def parse_from(self) -> nodes.FromImport:
+ node = nodes.FromImport(lineno=next(self.stream).lineno)
+ node.template = self.parse_expression()
+ self.stream.expect("name:import")
+ node.names = []
+
+ def parse_context() -> bool:
+ if self.stream.current.value in {
+ "with",
+ "without",
+ } and self.stream.look().test("name:context"):
+ node.with_context = next(self.stream).value == "with"
+ self.stream.skip()
+ return True
+ return False
+
+ while True:
+ if node.names:
+ self.stream.expect("comma")
+ if self.stream.current.type == "name":
+ if parse_context():
+ break
+ target = self.parse_assign_target(name_only=True)
+ if target.name.startswith("_"):
+ self.fail(
+ "names starting with an underline can not be imported",
+ target.lineno,
+ exc=TemplateAssertionError,
+ )
+ if self.stream.skip_if("name:as"):
+ alias = self.parse_assign_target(name_only=True)
+ node.names.append((target.name, alias.name))
+ else:
+ node.names.append(target.name)
+ if parse_context() or self.stream.current.type != "comma":
+ break
+ else:
+ self.stream.expect("name")
+ if not hasattr(node, "with_context"):
+ node.with_context = False
+ return node
+
+ def parse_signature(self, node: _MacroCall) -> None:
+ args = node.args = []
+ defaults = node.defaults = []
+ self.stream.expect("lparen")
+ while self.stream.current.type != "rparen":
+ if args:
+ self.stream.expect("comma")
+ arg = self.parse_assign_target(name_only=True)
+ arg.set_ctx("param")
+ if self.stream.skip_if("assign"):
+ defaults.append(self.parse_expression())
+ elif defaults:
+ self.fail("non-default argument follows default argument")
+ args.append(arg)
+ self.stream.expect("rparen")
+
+ def parse_call_block(self) -> nodes.CallBlock:
+ node = nodes.CallBlock(lineno=next(self.stream).lineno)
+ if self.stream.current.type == "lparen":
+ self.parse_signature(node)
+ else:
+ node.args = []
+ node.defaults = []
+
+ call_node = self.parse_expression()
+ if not isinstance(call_node, nodes.Call):
+ self.fail("expected call", node.lineno)
+ node.call = call_node
+ node.body = self.parse_statements(("name:endcall",), drop_needle=True)
+ return node
+
+ def parse_filter_block(self) -> nodes.FilterBlock:
+ node = nodes.FilterBlock(lineno=next(self.stream).lineno)
+ node.filter = self.parse_filter(None, start_inline=True) # type: ignore
+ node.body = self.parse_statements(("name:endfilter",), drop_needle=True)
+ return node
+
+ def parse_macro(self) -> nodes.Macro:
+ node = nodes.Macro(lineno=next(self.stream).lineno)
+ node.name = self.parse_assign_target(name_only=True).name
+ self.parse_signature(node)
+ node.body = self.parse_statements(("name:endmacro",), drop_needle=True)
+ return node
+
+ def parse_print(self) -> nodes.Output:
+ node = nodes.Output(lineno=next(self.stream).lineno)
+ node.nodes = []
+ while self.stream.current.type != "block_end":
+ if node.nodes:
+ self.stream.expect("comma")
+ node.nodes.append(self.parse_expression())
+ return node
+
+ @typing.overload
+ def parse_assign_target(
+ self, with_tuple: bool = ..., name_only: "te.Literal[True]" = ...
+ ) -> nodes.Name:
+ ...
+
+ @typing.overload
+ def parse_assign_target(
+ self,
+ with_tuple: bool = True,
+ name_only: bool = False,
+ extra_end_rules: t.Optional[t.Tuple[str, ...]] = None,
+ with_namespace: bool = False,
+ ) -> t.Union[nodes.NSRef, nodes.Name, nodes.Tuple]:
+ ...
+
+ def parse_assign_target(
+ self,
+ with_tuple: bool = True,
+ name_only: bool = False,
+ extra_end_rules: t.Optional[t.Tuple[str, ...]] = None,
+ with_namespace: bool = False,
+ ) -> t.Union[nodes.NSRef, nodes.Name, nodes.Tuple]:
+ """Parse an assignment target. As Jinja allows assignments to
+ tuples, this function can parse all allowed assignment targets. Per
+ default assignments to tuples are parsed, that can be disable however
+ by setting `with_tuple` to `False`. If only assignments to names are
+ wanted `name_only` can be set to `True`. The `extra_end_rules`
+ parameter is forwarded to the tuple parsing function. If
+ `with_namespace` is enabled, a namespace assignment may be parsed.
+ """
+ target: nodes.Expr
+
+ if with_namespace and self.stream.look().type == "dot":
+ token = self.stream.expect("name")
+ next(self.stream) # dot
+ attr = self.stream.expect("name")
+ target = nodes.NSRef(token.value, attr.value, lineno=token.lineno)
+ elif name_only:
+ token = self.stream.expect("name")
+ target = nodes.Name(token.value, "store", lineno=token.lineno)
+ else:
+ if with_tuple:
+ target = self.parse_tuple(
+ simplified=True, extra_end_rules=extra_end_rules
+ )
+ else:
+ target = self.parse_primary()
+
+ target.set_ctx("store")
+
+ if not target.can_assign():
+ self.fail(
+ f"can't assign to {type(target).__name__.lower()!r}", target.lineno
+ )
+
+ return target # type: ignore
+
+ def parse_expression(self, with_condexpr: bool = True) -> nodes.Expr:
+ """Parse an expression. Per default all expressions are parsed, if
+ the optional `with_condexpr` parameter is set to `False` conditional
+ expressions are not parsed.
+ """
+ if with_condexpr:
+ return self.parse_condexpr()
+ return self.parse_or()
+
+ def parse_condexpr(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ expr1 = self.parse_or()
+ expr3: t.Optional[nodes.Expr]
+
+ while self.stream.skip_if("name:if"):
+ expr2 = self.parse_or()
+ if self.stream.skip_if("name:else"):
+ expr3 = self.parse_condexpr()
+ else:
+ expr3 = None
+ expr1 = nodes.CondExpr(expr2, expr1, expr3, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return expr1
+
+ def parse_or(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ left = self.parse_and()
+ while self.stream.skip_if("name:or"):
+ right = self.parse_and()
+ left = nodes.Or(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_and(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ left = self.parse_not()
+ while self.stream.skip_if("name:and"):
+ right = self.parse_not()
+ left = nodes.And(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_not(self) -> nodes.Expr:
+ if self.stream.current.test("name:not"):
+ lineno = next(self.stream).lineno
+ return nodes.Not(self.parse_not(), lineno=lineno)
+ return self.parse_compare()
+
+ def parse_compare(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ expr = self.parse_math1()
+ ops = []
+ while True:
+ token_type = self.stream.current.type
+ if token_type in _compare_operators:
+ next(self.stream)
+ ops.append(nodes.Operand(token_type, self.parse_math1()))
+ elif self.stream.skip_if("name:in"):
+ ops.append(nodes.Operand("in", self.parse_math1()))
+ elif self.stream.current.test("name:not") and self.stream.look().test(
+ "name:in"
+ ):
+ self.stream.skip(2)
+ ops.append(nodes.Operand("notin", self.parse_math1()))
+ else:
+ break
+ lineno = self.stream.current.lineno
+ if not ops:
+ return expr
+ return nodes.Compare(expr, ops, lineno=lineno)
+
+ def parse_math1(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ left = self.parse_concat()
+ while self.stream.current.type in ("add", "sub"):
+ cls = _math_nodes[self.stream.current.type]
+ next(self.stream)
+ right = self.parse_concat()
+ left = cls(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_concat(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ args = [self.parse_math2()]
+ while self.stream.current.type == "tilde":
+ next(self.stream)
+ args.append(self.parse_math2())
+ if len(args) == 1:
+ return args[0]
+ return nodes.Concat(args, lineno=lineno)
+
+ def parse_math2(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ left = self.parse_pow()
+ while self.stream.current.type in ("mul", "div", "floordiv", "mod"):
+ cls = _math_nodes[self.stream.current.type]
+ next(self.stream)
+ right = self.parse_pow()
+ left = cls(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_pow(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ left = self.parse_unary()
+ while self.stream.current.type == "pow":
+ next(self.stream)
+ right = self.parse_unary()
+ left = nodes.Pow(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_unary(self, with_filter: bool = True) -> nodes.Expr:
+ token_type = self.stream.current.type
+ lineno = self.stream.current.lineno
+ node: nodes.Expr
+
+ if token_type == "sub":
+ next(self.stream)
+ node = nodes.Neg(self.parse_unary(False), lineno=lineno)
+ elif token_type == "add":
+ next(self.stream)
+ node = nodes.Pos(self.parse_unary(False), lineno=lineno)
+ else:
+ node = self.parse_primary()
+ node = self.parse_postfix(node)
+ if with_filter:
+ node = self.parse_filter_expr(node)
+ return node
+
+ def parse_primary(self) -> nodes.Expr:
+ token = self.stream.current
+ node: nodes.Expr
+ if token.type == "name":
+ if token.value in ("true", "false", "True", "False"):
+ node = nodes.Const(token.value in ("true", "True"), lineno=token.lineno)
+ elif token.value in ("none", "None"):
+ node = nodes.Const(None, lineno=token.lineno)
+ else:
+ node = nodes.Name(token.value, "load", lineno=token.lineno)
+ next(self.stream)
+ elif token.type == "string":
+ next(self.stream)
+ buf = [token.value]
+ lineno = token.lineno
+ while self.stream.current.type == "string":
+ buf.append(self.stream.current.value)
+ next(self.stream)
+ node = nodes.Const("".join(buf), lineno=lineno)
+ elif token.type in ("integer", "float"):
+ next(self.stream)
+ node = nodes.Const(token.value, lineno=token.lineno)
+ elif token.type == "lparen":
+ next(self.stream)
+ node = self.parse_tuple(explicit_parentheses=True)
+ self.stream.expect("rparen")
+ elif token.type == "lbracket":
+ node = self.parse_list()
+ elif token.type == "lbrace":
+ node = self.parse_dict()
+ else:
+ self.fail(f"unexpected {describe_token(token)!r}", token.lineno)
+ return node
+
+ def parse_tuple(
+ self,
+ simplified: bool = False,
+ with_condexpr: bool = True,
+ extra_end_rules: t.Optional[t.Tuple[str, ...]] = None,
+ explicit_parentheses: bool = False,
+ ) -> t.Union[nodes.Tuple, nodes.Expr]:
+ """Works like `parse_expression` but if multiple expressions are
+ delimited by a comma a :class:`~jinja2.nodes.Tuple` node is created.
+ This method could also return a regular expression instead of a tuple
+ if no commas where found.
+
+ The default parsing mode is a full tuple. If `simplified` is `True`
+ only names and literals are parsed. The `no_condexpr` parameter is
+ forwarded to :meth:`parse_expression`.
+
+ Because tuples do not require delimiters and may end in a bogus comma
+ an extra hint is needed that marks the end of a tuple. For example
+ for loops support tuples between `for` and `in`. In that case the
+ `extra_end_rules` is set to ``['name:in']``.
+
+ `explicit_parentheses` is true if the parsing was triggered by an
+ expression in parentheses. This is used to figure out if an empty
+ tuple is a valid expression or not.
+ """
+ lineno = self.stream.current.lineno
+ if simplified:
+ parse = self.parse_primary
+ elif with_condexpr:
+ parse = self.parse_expression
+ else:
+
+ def parse() -> nodes.Expr:
+ return self.parse_expression(with_condexpr=False)
+
+ args: t.List[nodes.Expr] = []
+ is_tuple = False
+
+ while True:
+ if args:
+ self.stream.expect("comma")
+ if self.is_tuple_end(extra_end_rules):
+ break
+ args.append(parse())
+ if self.stream.current.type == "comma":
+ is_tuple = True
+ else:
+ break
+ lineno = self.stream.current.lineno
+
+ if not is_tuple:
+ if args:
+ return args[0]
+
+ # if we don't have explicit parentheses, an empty tuple is
+ # not a valid expression. This would mean nothing (literally
+ # nothing) in the spot of an expression would be an empty
+ # tuple.
+ if not explicit_parentheses:
+ self.fail(
+ "Expected an expression,"
+ f" got {describe_token(self.stream.current)!r}"
+ )
+
+ return nodes.Tuple(args, "load", lineno=lineno)
+
+ def parse_list(self) -> nodes.List:
+ token = self.stream.expect("lbracket")
+ items: t.List[nodes.Expr] = []
+ while self.stream.current.type != "rbracket":
+ if items:
+ self.stream.expect("comma")
+ if self.stream.current.type == "rbracket":
+ break
+ items.append(self.parse_expression())
+ self.stream.expect("rbracket")
+ return nodes.List(items, lineno=token.lineno)
+
+ def parse_dict(self) -> nodes.Dict:
+ token = self.stream.expect("lbrace")
+ items: t.List[nodes.Pair] = []
+ while self.stream.current.type != "rbrace":
+ if items:
+ self.stream.expect("comma")
+ if self.stream.current.type == "rbrace":
+ break
+ key = self.parse_expression()
+ self.stream.expect("colon")
+ value = self.parse_expression()
+ items.append(nodes.Pair(key, value, lineno=key.lineno))
+ self.stream.expect("rbrace")
+ return nodes.Dict(items, lineno=token.lineno)
+
+ def parse_postfix(self, node: nodes.Expr) -> nodes.Expr:
+ while True:
+ token_type = self.stream.current.type
+ if token_type == "dot" or token_type == "lbracket":
+ node = self.parse_subscript(node)
+ # calls are valid both after postfix expressions (getattr
+ # and getitem) as well as filters and tests
+ elif token_type == "lparen":
+ node = self.parse_call(node)
+ else:
+ break
+ return node
+
+ def parse_filter_expr(self, node: nodes.Expr) -> nodes.Expr:
+ while True:
+ token_type = self.stream.current.type
+ if token_type == "pipe":
+ node = self.parse_filter(node) # type: ignore
+ elif token_type == "name" and self.stream.current.value == "is":
+ node = self.parse_test(node)
+ # calls are valid both after postfix expressions (getattr
+ # and getitem) as well as filters and tests
+ elif token_type == "lparen":
+ node = self.parse_call(node)
+ else:
+ break
+ return node
+
+ def parse_subscript(
+ self, node: nodes.Expr
+ ) -> t.Union[nodes.Getattr, nodes.Getitem]:
+ token = next(self.stream)
+ arg: nodes.Expr
+
+ if token.type == "dot":
+ attr_token = self.stream.current
+ next(self.stream)
+ if attr_token.type == "name":
+ return nodes.Getattr(
+ node, attr_token.value, "load", lineno=token.lineno
+ )
+ elif attr_token.type != "integer":
+ self.fail("expected name or number", attr_token.lineno)
+ arg = nodes.Const(attr_token.value, lineno=attr_token.lineno)
+ return nodes.Getitem(node, arg, "load", lineno=token.lineno)
+ if token.type == "lbracket":
+ args: t.List[nodes.Expr] = []
+ while self.stream.current.type != "rbracket":
+ if args:
+ self.stream.expect("comma")
+ args.append(self.parse_subscribed())
+ self.stream.expect("rbracket")
+ if len(args) == 1:
+ arg = args[0]
+ else:
+ arg = nodes.Tuple(args, "load", lineno=token.lineno)
+ return nodes.Getitem(node, arg, "load", lineno=token.lineno)
+ self.fail("expected subscript expression", token.lineno)
+
+ def parse_subscribed(self) -> nodes.Expr:
+ lineno = self.stream.current.lineno
+ args: t.List[t.Optional[nodes.Expr]]
+
+ if self.stream.current.type == "colon":
+ next(self.stream)
+ args = [None]
+ else:
+ node = self.parse_expression()
+ if self.stream.current.type != "colon":
+ return node
+ next(self.stream)
+ args = [node]
+
+ if self.stream.current.type == "colon":
+ args.append(None)
+ elif self.stream.current.type not in ("rbracket", "comma"):
+ args.append(self.parse_expression())
+ else:
+ args.append(None)
+
+ if self.stream.current.type == "colon":
+ next(self.stream)
+ if self.stream.current.type not in ("rbracket", "comma"):
+ args.append(self.parse_expression())
+ else:
+ args.append(None)
+ else:
+ args.append(None)
+
+ return nodes.Slice(lineno=lineno, *args)
+
+ def parse_call_args(self) -> t.Tuple:
+ token = self.stream.expect("lparen")
+ args = []
+ kwargs = []
+ dyn_args = None
+ dyn_kwargs = None
+ require_comma = False
+
+ def ensure(expr: bool) -> None:
+ if not expr:
+ self.fail("invalid syntax for function call expression", token.lineno)
+
+ while self.stream.current.type != "rparen":
+ if require_comma:
+ self.stream.expect("comma")
+
+ # support for trailing comma
+ if self.stream.current.type == "rparen":
+ break
+
+ if self.stream.current.type == "mul":
+ ensure(dyn_args is None and dyn_kwargs is None)
+ next(self.stream)
+ dyn_args = self.parse_expression()
+ elif self.stream.current.type == "pow":
+ ensure(dyn_kwargs is None)
+ next(self.stream)
+ dyn_kwargs = self.parse_expression()
+ else:
+ if (
+ self.stream.current.type == "name"
+ and self.stream.look().type == "assign"
+ ):
+ # Parsing a kwarg
+ ensure(dyn_kwargs is None)
+ key = self.stream.current.value
+ self.stream.skip(2)
+ value = self.parse_expression()
+ kwargs.append(nodes.Keyword(key, value, lineno=value.lineno))
+ else:
+ # Parsing an arg
+ ensure(dyn_args is None and dyn_kwargs is None and not kwargs)
+ args.append(self.parse_expression())
+
+ require_comma = True
+
+ self.stream.expect("rparen")
+ return args, kwargs, dyn_args, dyn_kwargs
+
+ def parse_call(self, node: nodes.Expr) -> nodes.Call:
+ # The lparen will be expected in parse_call_args, but the lineno
+ # needs to be recorded before the stream is advanced.
+ token = self.stream.current
+ args, kwargs, dyn_args, dyn_kwargs = self.parse_call_args()
+ return nodes.Call(node, args, kwargs, dyn_args, dyn_kwargs, lineno=token.lineno)
+
+ def parse_filter(
+ self, node: t.Optional[nodes.Expr], start_inline: bool = False
+ ) -> t.Optional[nodes.Expr]:
+ while self.stream.current.type == "pipe" or start_inline:
+ if not start_inline:
+ next(self.stream)
+ token = self.stream.expect("name")
+ name = token.value
+ while self.stream.current.type == "dot":
+ next(self.stream)
+ name += "." + self.stream.expect("name").value
+ if self.stream.current.type == "lparen":
+ args, kwargs, dyn_args, dyn_kwargs = self.parse_call_args()
+ else:
+ args = []
+ kwargs = []
+ dyn_args = dyn_kwargs = None
+ node = nodes.Filter(
+ node, name, args, kwargs, dyn_args, dyn_kwargs, lineno=token.lineno
+ )
+ start_inline = False
+ return node
+
+ def parse_test(self, node: nodes.Expr) -> nodes.Expr:
+ token = next(self.stream)
+ if self.stream.current.test("name:not"):
+ next(self.stream)
+ negated = True
+ else:
+ negated = False
+ name = self.stream.expect("name").value
+ while self.stream.current.type == "dot":
+ next(self.stream)
+ name += "." + self.stream.expect("name").value
+ dyn_args = dyn_kwargs = None
+ kwargs = []
+ if self.stream.current.type == "lparen":
+ args, kwargs, dyn_args, dyn_kwargs = self.parse_call_args()
+ elif self.stream.current.type in {
+ "name",
+ "string",
+ "integer",
+ "float",
+ "lparen",
+ "lbracket",
+ "lbrace",
+ } and not self.stream.current.test_any("name:else", "name:or", "name:and"):
+ if self.stream.current.test("name:is"):
+ self.fail("You cannot chain multiple tests with is")
+ arg_node = self.parse_primary()
+ arg_node = self.parse_postfix(arg_node)
+ args = [arg_node]
+ else:
+ args = []
+ node = nodes.Test(
+ node, name, args, kwargs, dyn_args, dyn_kwargs, lineno=token.lineno
+ )
+ if negated:
+ node = nodes.Not(node, lineno=token.lineno)
+ return node
+
+ def subparse(
+ self, end_tokens: t.Optional[t.Tuple[str, ...]] = None
+ ) -> t.List[nodes.Node]:
+ body: t.List[nodes.Node] = []
+ data_buffer: t.List[nodes.Node] = []
+ add_data = data_buffer.append
+
+ if end_tokens is not None:
+ self._end_token_stack.append(end_tokens)
+
+ def flush_data() -> None:
+ if data_buffer:
+ lineno = data_buffer[0].lineno
+ body.append(nodes.Output(data_buffer[:], lineno=lineno))
+ del data_buffer[:]
+
+ try:
+ while self.stream:
+ token = self.stream.current
+ if token.type == "data":
+ if token.value:
+ add_data(nodes.TemplateData(token.value, lineno=token.lineno))
+ next(self.stream)
+ elif token.type == "variable_begin":
+ next(self.stream)
+ add_data(self.parse_tuple(with_condexpr=True))
+ self.stream.expect("variable_end")
+ elif token.type == "block_begin":
+ flush_data()
+ next(self.stream)
+ if end_tokens is not None and self.stream.current.test_any(
+ *end_tokens
+ ):
+ return body
+ rv = self.parse_statement()
+ if isinstance(rv, list):
+ body.extend(rv)
+ else:
+ body.append(rv)
+ self.stream.expect("block_end")
+ else:
+ raise AssertionError("internal parsing error")
+
+ flush_data()
+ finally:
+ if end_tokens is not None:
+ self._end_token_stack.pop()
+ return body
+
+ def parse(self) -> nodes.Template:
+ """Parse the whole template into a `Template` node."""
+ result = nodes.Template(self.subparse(), lineno=1)
+ result.set_environment(self.environment)
+ return result
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 23:51:46 +0000