| """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 |
