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//proc/self/root/lib/python3.6/site-packages/jinja2/parser.py
# -*- coding: utf-8 -*- """Parse tokens from the lexer into nodes for the compiler.""" from . import nodes from ._compat import imap from .exceptions import TemplateAssertionError from .exceptions import TemplateSyntaxError from .lexer import describe_token from .lexer import describe_token_expr _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 = { "add": nodes.Add, "sub": nodes.Sub, "mul": nodes.Mul, "div": nodes.Div, "floordiv": nodes.FloorDiv, "mod": nodes.Mod, } class Parser(object): """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, source, name=None, filename=None, state=None): self.environment = environment self.stream = environment._tokenize(source, name, filename, state) self.name = name self.filename = filename self.closed = False self.extensions = {} for extension in environment.iter_extensions(): for tag in extension.tags: self.extensions[tag] = extension.parse self._last_identifier = 0 self._tag_stack = [] self._end_token_stack = [] def fail(self, msg, lineno=None, exc=TemplateSyntaxError): """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, end_token_stack, lineno): expected = [] for exprs in end_token_stack: expected.extend(imap(describe_token_expr, exprs)) if end_token_stack: currently_looking = " or ".join( "'%s'" % describe_token_expr(expr) for expr in end_token_stack[-1] ) else: currently_looking = None if name is None: message = ["Unexpected end of template."] else: message = ["Encountered unknown tag '%s'." % name] 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, but currently looking " "for %s." % currently_looking ) else: message.append( "Jinja was looking for the following tags: " "%s." % currently_looking ) if self._tag_stack: message.append( "The innermost block that needs to be " "closed is '%s'." % self._tag_stack[-1] ) self.fail(" ".join(message), lineno) def fail_unknown_tag(self, name, lineno=None): """Called if the parser encounters an unknown tag. Tries to fail with a human readable error message that could help to identify the problem. """ return self._fail_ut_eof(name, self._end_token_stack, lineno) def fail_eof(self, end_tokens=None, lineno=None): """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) return self._fail_ut_eof(None, stack, lineno) def is_tuple_end(self, extra_end_rules=None): """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) return False def free_identifier(self, lineno=None): """Return a new free identifier as :class:`~jinja2.nodes.InternalName`.""" self._last_identifier += 1 rv = object.__new__(nodes.InternalName) nodes.Node.__init__(rv, "fi%d" % self._last_identifier, lineno=lineno) return rv def parse_statement(self): """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: return getattr(self, "parse_" + self.stream.current.value)() 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, drop_needle=False): """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): """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): """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): """Parse an if construct.""" node = result = nodes.If(lineno=self.stream.expect("name:if").lineno) while 1: 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): node = nodes.With(lineno=next(self.stream).lineno) targets = [] values = [] 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): 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): node = nodes.Block(lineno=next(self.stream).lineno) node.name = self.stream.expect("name").value node.scoped = self.stream.skip_if("name:scoped") # 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) self.stream.skip_if("name:" + node.name) return node def parse_extends(self): node = nodes.Extends(lineno=next(self.stream).lineno) node.template = self.parse_expression() return node def parse_import_context(self, node, default): 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): 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): 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): node = nodes.FromImport(lineno=next(self.stream).lineno) node.template = self.parse_expression() self.stream.expect("name:import") node.names = [] def parse_context(): 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 1: 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): node.args = args = [] node.defaults = 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): node = nodes.CallBlock(lineno=next(self.stream).lineno) if self.stream.current.type == "lparen": self.parse_signature(node) else: node.args = [] node.defaults = [] node.call = self.parse_expression() if not isinstance(node.call, nodes.Call): self.fail("expected call", node.lineno) node.body = self.parse_statements(("name:endcall",), drop_needle=True) return node def parse_filter_block(self): node = nodes.FilterBlock(lineno=next(self.stream).lineno) node.filter = self.parse_filter(None, start_inline=True) node.body = self.parse_statements(("name:endfilter",), drop_needle=True) return node def parse_macro(self): 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): 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=True, name_only=False, extra_end_rules=None, with_namespace=False, ): """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. """ 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( "can't assign to %r" % target.__class__.__name__.lower(), target.lineno ) return target def parse_expression(self, with_condexpr=True): """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): lineno = self.stream.current.lineno expr1 = self.parse_or() 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): 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): 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): 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): lineno = self.stream.current.lineno expr = self.parse_math1() ops = [] while 1: 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): 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): 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): 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): 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=True): token_type = self.stream.current.type lineno = self.stream.current.lineno 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): token = self.stream.current 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("unexpected '%s'" % describe_token(token), token.lineno) return node def parse_tuple( self, simplified=False, with_condexpr=True, extra_end_rules=None, explicit_parentheses=False, ): """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(): return self.parse_expression(with_condexpr=False) args = [] is_tuple = False while 1: 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, got '%s'" % describe_token(self.stream.current) ) return nodes.Tuple(args, "load", lineno=lineno) def parse_list(self): token = self.stream.expect("lbracket") items = [] 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): token = self.stream.expect("lbrace") items = [] 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): while 1: 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): while 1: token_type = self.stream.current.type if token_type == "pipe": node = self.parse_filter(node) 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): token = next(self.stream) 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 = [] 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): lineno = self.stream.current.lineno 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(self, node): token = self.stream.expect("lparen") args = [] kwargs = [] dyn_args = dyn_kwargs = None require_comma = False def ensure(expr): 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") if node is None: return args, kwargs, dyn_args, dyn_kwargs return nodes.Call(node, args, kwargs, dyn_args, dyn_kwargs, lineno=token.lineno) def parse_filter(self, node, start_inline=False): 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(None) 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): 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(None) 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=None): body = [] data_buffer = [] add_data = data_buffer.append if end_tokens is not None: self._end_token_stack.append(end_tokens) def flush_data(): 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): """Parse the whole template into a `Template` node.""" result = nodes.Template(self.subparse(), lineno=1) result.set_environment(self.environment) return result
