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"""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: | |
for body_node in node.body: | |
if not isinstance(body_node, nodes.Output) or any( | |
not isinstance(output_node, nodes.TemplateData) | |
or not output_node.data.isspace() | |
for output_node in body_node.nodes | |
): | |
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 | |
def parse_assign_target( | |
self, with_tuple: bool = ..., name_only: "te.Literal[True]" = ... | |
) -> nodes.Name: ... | |
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) # noqa: B026 | |
def parse_call_args( | |
self, | |
) -> t.Tuple[ | |
t.List[nodes.Expr], | |
t.List[nodes.Keyword], | |
t.Optional[nodes.Expr], | |
t.Optional[nodes.Expr], | |
]: | |
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: t.List[nodes.Keyword] = [] | |
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 | |