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Posted to commits@ambari.apache.org by ao...@apache.org on 2014/09/03 20:20:02 UTC
[17/22] AMBARI-7138. Ambari RPM deals with jinja2 dependency
incorrectly (aonishuk)
http://git-wip-us.apache.org/repos/asf/ambari/blob/7c3ea59f/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/nodes.py
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diff --git a/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/nodes.py b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/nodes.py
new file mode 100644
index 0000000..804070c
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+++ b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/nodes.py
@@ -0,0 +1,901 @@
+# -*- coding: utf-8 -*-
+"""
+ ambari_jinja2.nodes
+ ~~~~~~~~~~~~
+
+ This module implements additional nodes derived from the ast base node.
+
+ It also provides some node tree helper functions like `in_lineno` and
+ `get_nodes` used by the parser and translator in order to normalize
+ python and jinja nodes.
+
+ :copyright: (c) 2010 by the Jinja Team.
+ :license: BSD, see LICENSE for more details.
+"""
+import operator
+from itertools import chain, izip
+from collections import deque
+from ambari_jinja2.utils import Markup, MethodType, FunctionType
+
+
+#: the types we support for context functions
+_context_function_types = (FunctionType, MethodType)
+
+
+_binop_to_func = {
+ '*': operator.mul,
+ '/': operator.truediv,
+ '//': operator.floordiv,
+ '**': operator.pow,
+ '%': operator.mod,
+ '+': operator.add,
+ '-': operator.sub
+}
+
+_uaop_to_func = {
+ 'not': operator.not_,
+ '+': operator.pos,
+ '-': operator.neg
+}
+
+_cmpop_to_func = {
+ 'eq': operator.eq,
+ 'ne': operator.ne,
+ 'gt': operator.gt,
+ 'gteq': operator.ge,
+ 'lt': operator.lt,
+ 'lteq': operator.le,
+ 'in': lambda a, b: a in b,
+ 'notin': lambda a, b: a not in b
+}
+
+
+class Impossible(Exception):
+ """Raised if the node could not perform a requested action."""
+
+
+class NodeType(type):
+ """A metaclass for nodes that handles the field and attribute
+ inheritance. fields and attributes from the parent class are
+ automatically forwarded to the child."""
+
+ def __new__(cls, name, bases, d):
+ for attr in 'fields', 'attributes':
+ storage = []
+ storage.extend(getattr(bases[0], attr, ()))
+ storage.extend(d.get(attr, ()))
+ assert len(bases) == 1, 'multiple inheritance not allowed'
+ assert len(storage) == len(set(storage)), 'layout conflict'
+ d[attr] = tuple(storage)
+ d.setdefault('abstract', False)
+ return type.__new__(cls, name, bases, d)
+
+
+class EvalContext(object):
+ """Holds evaluation time information. Custom attributes can be attached
+ to it in extensions.
+ """
+
+ def __init__(self, environment, template_name=None):
+ if callable(environment.autoescape):
+ self.autoescape = environment.autoescape(template_name)
+ else:
+ self.autoescape = environment.autoescape
+ self.volatile = False
+
+ def save(self):
+ return self.__dict__.copy()
+
+ def revert(self, old):
+ self.__dict__.clear()
+ self.__dict__.update(old)
+
+
+def get_eval_context(node, ctx):
+ if ctx is None:
+ if node.environment is None:
+ raise RuntimeError('if no eval context is passed, the '
+ 'node must have an attached '
+ 'environment.')
+ return EvalContext(node.environment)
+ return ctx
+
+
+class Node(object):
+ """Baseclass for all Jinja2 nodes. There are a number of nodes available
+ of different types. There are three major types:
+
+ - :class:`Stmt`: statements
+ - :class:`Expr`: expressions
+ - :class:`Helper`: helper nodes
+ - :class:`Template`: the outermost wrapper node
+
+ All nodes have fields and attributes. Fields may be other nodes, lists,
+ or arbitrary values. Fields are passed to the constructor as regular
+ positional arguments, attributes as keyword arguments. Each node has
+ two attributes: `lineno` (the line number of the node) and `environment`.
+ The `environment` attribute is set at the end of the parsing process for
+ all nodes automatically.
+ """
+ __metaclass__ = NodeType
+ fields = ()
+ attributes = ('lineno', 'environment')
+ abstract = True
+
+ def __init__(self, *fields, **attributes):
+ if self.abstract:
+ raise TypeError('abstract nodes are not instanciable')
+ if fields:
+ if len(fields) != len(self.fields):
+ if not self.fields:
+ raise TypeError('%r takes 0 arguments' %
+ self.__class__.__name__)
+ raise TypeError('%r takes 0 or %d argument%s' % (
+ self.__class__.__name__,
+ len(self.fields),
+ len(self.fields) != 1 and 's' or ''
+ ))
+ for name, arg in izip(self.fields, fields):
+ setattr(self, name, arg)
+ for attr in self.attributes:
+ setattr(self, attr, attributes.pop(attr, None))
+ if attributes:
+ raise TypeError('unknown attribute %r' %
+ iter(attributes).next())
+
+ def iter_fields(self, exclude=None, only=None):
+ """This method iterates over all fields that are defined and yields
+ ``(key, value)`` tuples. Per default all fields are returned, but
+ it's possible to limit that to some fields by providing the `only`
+ parameter or to exclude some using the `exclude` parameter. Both
+ should be sets or tuples of field names.
+ """
+ for name in self.fields:
+ if (exclude is only is None) or \
+ (exclude is not None and name not in exclude) or \
+ (only is not None and name in only):
+ try:
+ yield name, getattr(self, name)
+ except AttributeError:
+ pass
+
+ def iter_child_nodes(self, exclude=None, only=None):
+ """Iterates over all direct child nodes of the node. This iterates
+ over all fields and yields the values of they are nodes. If the value
+ of a field is a list all the nodes in that list are returned.
+ """
+ for field, item in self.iter_fields(exclude, only):
+ if isinstance(item, list):
+ for n in item:
+ if isinstance(n, Node):
+ yield n
+ elif isinstance(item, Node):
+ yield item
+
+ def find(self, node_type):
+ """Find the first node of a given type. If no such node exists the
+ return value is `None`.
+ """
+ for result in self.find_all(node_type):
+ return result
+
+ def find_all(self, node_type):
+ """Find all the nodes of a given type. If the type is a tuple,
+ the check is performed for any of the tuple items.
+ """
+ for child in self.iter_child_nodes():
+ if isinstance(child, node_type):
+ yield child
+ for result in child.find_all(node_type):
+ yield result
+
+ def set_ctx(self, ctx):
+ """Reset the context of a node and all child nodes. Per default the
+ parser will all generate nodes that have a 'load' context as it's the
+ most common one. This method is used in the parser to set assignment
+ targets and other nodes to a store context.
+ """
+ todo = deque([self])
+ while todo:
+ node = todo.popleft()
+ if 'ctx' in node.fields:
+ node.ctx = ctx
+ todo.extend(node.iter_child_nodes())
+ return self
+
+ def set_lineno(self, lineno, override=False):
+ """Set the line numbers of the node and children."""
+ todo = deque([self])
+ while todo:
+ node = todo.popleft()
+ if 'lineno' in node.attributes:
+ if node.lineno is None or override:
+ node.lineno = lineno
+ todo.extend(node.iter_child_nodes())
+ return self
+
+ def set_environment(self, environment):
+ """Set the environment for all nodes."""
+ todo = deque([self])
+ while todo:
+ node = todo.popleft()
+ node.environment = environment
+ todo.extend(node.iter_child_nodes())
+ return self
+
+ def __eq__(self, other):
+ return type(self) is type(other) and \
+ tuple(self.iter_fields()) == tuple(other.iter_fields())
+
+ def __ne__(self, other):
+ return not self.__eq__(other)
+
+ def __repr__(self):
+ return '%s(%s)' % (
+ self.__class__.__name__,
+ ', '.join('%s=%r' % (arg, getattr(self, arg, None)) for
+ arg in self.fields)
+ )
+
+
+class Stmt(Node):
+ """Base node for all statements."""
+ abstract = True
+
+
+class Helper(Node):
+ """Nodes that exist in a specific context only."""
+ abstract = True
+
+
+class Template(Node):
+ """Node that represents a template. This must be the outermost node that
+ is passed to the compiler.
+ """
+ fields = ('body',)
+
+
+class Output(Stmt):
+ """A node that holds multiple expressions which are then printed out.
+ This is used both for the `print` statement and the regular template data.
+ """
+ fields = ('nodes',)
+
+
+class Extends(Stmt):
+ """Represents an extends statement."""
+ fields = ('template',)
+
+
+class For(Stmt):
+ """The for loop. `target` is the target for the iteration (usually a
+ :class:`Name` or :class:`Tuple`), `iter` the iterable. `body` is a list
+ of nodes that are used as loop-body, and `else_` a list of nodes for the
+ `else` block. If no else node exists it has to be an empty list.
+
+ For filtered nodes an expression can be stored as `test`, otherwise `None`.
+ """
+ fields = ('target', 'iter', 'body', 'else_', 'test', 'recursive')
+
+
+class If(Stmt):
+ """If `test` is true, `body` is rendered, else `else_`."""
+ fields = ('test', 'body', 'else_')
+
+
+class Macro(Stmt):
+ """A macro definition. `name` is the name of the macro, `args` a list of
+ arguments and `defaults` a list of defaults if there are any. `body` is
+ a list of nodes for the macro body.
+ """
+ fields = ('name', 'args', 'defaults', 'body')
+
+
+class CallBlock(Stmt):
+ """Like a macro without a name but a call instead. `call` is called with
+ the unnamed macro as `caller` argument this node holds.
+ """
+ fields = ('call', 'args', 'defaults', 'body')
+
+
+class FilterBlock(Stmt):
+ """Node for filter sections."""
+ fields = ('body', 'filter')
+
+
+class Block(Stmt):
+ """A node that represents a block."""
+ fields = ('name', 'body', 'scoped')
+
+
+class Include(Stmt):
+ """A node that represents the include tag."""
+ fields = ('template', 'with_context', 'ignore_missing')
+
+
+class Import(Stmt):
+ """A node that represents the import tag."""
+ fields = ('template', 'target', 'with_context')
+
+
+class FromImport(Stmt):
+ """A node that represents the from import tag. It's important to not
+ pass unsafe names to the name attribute. The compiler translates the
+ attribute lookups directly into getattr calls and does *not* use the
+ subscript callback of the interface. As exported variables may not
+ start with double underscores (which the parser asserts) this is not a
+ problem for regular Jinja code, but if this node is used in an extension
+ extra care must be taken.
+
+ The list of names may contain tuples if aliases are wanted.
+ """
+ fields = ('template', 'names', 'with_context')
+
+
+class ExprStmt(Stmt):
+ """A statement that evaluates an expression and discards the result."""
+ fields = ('node',)
+
+
+class Assign(Stmt):
+ """Assigns an expression to a target."""
+ fields = ('target', 'node')
+
+
+class Expr(Node):
+ """Baseclass for all expressions."""
+ abstract = True
+
+ def as_const(self, eval_ctx=None):
+ """Return the value of the expression as constant or raise
+ :exc:`Impossible` if this was not possible.
+
+ An :class:`EvalContext` can be provided, if none is given
+ a default context is created which requires the nodes to have
+ an attached environment.
+
+ .. versionchanged:: 2.4
+ the `eval_ctx` parameter was added.
+ """
+ raise Impossible()
+
+ def can_assign(self):
+ """Check if it's possible to assign something to this node."""
+ return False
+
+
+class BinExpr(Expr):
+ """Baseclass for all binary expressions."""
+ fields = ('left', 'right')
+ operator = None
+ abstract = True
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ f = _binop_to_func[self.operator]
+ try:
+ return f(self.left.as_const(eval_ctx), self.right.as_const(eval_ctx))
+ except:
+ raise Impossible()
+
+
+class UnaryExpr(Expr):
+ """Baseclass for all unary expressions."""
+ fields = ('node',)
+ operator = None
+ abstract = True
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ f = _uaop_to_func[self.operator]
+ try:
+ return f(self.node.as_const(eval_ctx))
+ except:
+ raise Impossible()
+
+
+class Name(Expr):
+ """Looks up a name or stores a value in a name.
+ The `ctx` of the node can be one of the following values:
+
+ - `store`: store a value in the name
+ - `load`: load that name
+ - `param`: like `store` but if the name was defined as function parameter.
+ """
+ fields = ('name', 'ctx')
+
+ def can_assign(self):
+ return self.name not in ('true', 'false', 'none',
+ 'True', 'False', 'None')
+
+
+class Literal(Expr):
+ """Baseclass for literals."""
+ abstract = True
+
+
+class Const(Literal):
+ """All constant values. The parser will return this node for simple
+ constants such as ``42`` or ``"foo"`` but it can be used to store more
+ complex values such as lists too. Only constants with a safe
+ representation (objects where ``eval(repr(x)) == x`` is true).
+ """
+ fields = ('value',)
+
+ def as_const(self, eval_ctx=None):
+ return self.value
+
+ @classmethod
+ def from_untrusted(cls, value, lineno=None, environment=None):
+ """Return a const object if the value is representable as
+ constant value in the generated code, otherwise it will raise
+ an `Impossible` exception.
+ """
+ from compiler import has_safe_repr
+ if not has_safe_repr(value):
+ raise Impossible()
+ return cls(value, lineno=lineno, environment=environment)
+
+
+class TemplateData(Literal):
+ """A constant template string."""
+ fields = ('data',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if eval_ctx.volatile:
+ raise Impossible()
+ if eval_ctx.autoescape:
+ return Markup(self.data)
+ return self.data
+
+
+class Tuple(Literal):
+ """For loop unpacking and some other things like multiple arguments
+ for subscripts. Like for :class:`Name` `ctx` specifies if the tuple
+ is used for loading the names or storing.
+ """
+ fields = ('items', 'ctx')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return tuple(x.as_const(eval_ctx) for x in self.items)
+
+ def can_assign(self):
+ for item in self.items:
+ if not item.can_assign():
+ return False
+ return True
+
+
+class List(Literal):
+ """Any list literal such as ``[1, 2, 3]``"""
+ fields = ('items',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return [x.as_const(eval_ctx) for x in self.items]
+
+
+class Dict(Literal):
+ """Any dict literal such as ``{1: 2, 3: 4}``. The items must be a list of
+ :class:`Pair` nodes.
+ """
+ fields = ('items',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return dict(x.as_const(eval_ctx) for x in self.items)
+
+
+class Pair(Helper):
+ """A key, value pair for dicts."""
+ fields = ('key', 'value')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return self.key.as_const(eval_ctx), self.value.as_const(eval_ctx)
+
+
+class Keyword(Helper):
+ """A key, value pair for keyword arguments where key is a string."""
+ fields = ('key', 'value')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return self.key, self.value.as_const(eval_ctx)
+
+
+class CondExpr(Expr):
+ """A conditional expression (inline if expression). (``{{
+ foo if bar else baz }}``)
+ """
+ fields = ('test', 'expr1', 'expr2')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if self.test.as_const(eval_ctx):
+ return self.expr1.as_const(eval_ctx)
+
+ # if we evaluate to an undefined object, we better do that at runtime
+ if self.expr2 is None:
+ raise Impossible()
+
+ return self.expr2.as_const(eval_ctx)
+
+
+class Filter(Expr):
+ """This node applies a filter on an expression. `name` is the name of
+ the filter, the rest of the fields are the same as for :class:`Call`.
+
+ If the `node` of a filter is `None` the contents of the last buffer are
+ filtered. Buffers are created by macros and filter blocks.
+ """
+ fields = ('node', 'name', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if eval_ctx.volatile or self.node is None:
+ raise Impossible()
+ # we have to be careful here because we call filter_ below.
+ # if this variable would be called filter, 2to3 would wrap the
+ # call in a list beause it is assuming we are talking about the
+ # builtin filter function here which no longer returns a list in
+ # python 3. because of that, do not rename filter_ to filter!
+ filter_ = self.environment.filters.get(self.name)
+ if filter_ is None or getattr(filter_, 'contextfilter', False):
+ raise Impossible()
+ obj = self.node.as_const(eval_ctx)
+ args = [x.as_const(eval_ctx) for x in self.args]
+ if getattr(filter_, 'evalcontextfilter', False):
+ args.insert(0, eval_ctx)
+ elif getattr(filter_, 'environmentfilter', False):
+ args.insert(0, self.environment)
+ kwargs = dict(x.as_const(eval_ctx) for x in self.kwargs)
+ if self.dyn_args is not None:
+ try:
+ args.extend(self.dyn_args.as_const(eval_ctx))
+ except:
+ raise Impossible()
+ if self.dyn_kwargs is not None:
+ try:
+ kwargs.update(self.dyn_kwargs.as_const(eval_ctx))
+ except:
+ raise Impossible()
+ try:
+ return filter_(obj, *args, **kwargs)
+ except:
+ raise Impossible()
+
+
+class Test(Expr):
+ """Applies a test on an expression. `name` is the name of the test, the
+ rest of the fields are the same as for :class:`Call`.
+ """
+ fields = ('node', 'name', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+
+class Call(Expr):
+ """Calls an expression. `args` is a list of arguments, `kwargs` a list
+ of keyword arguments (list of :class:`Keyword` nodes), and `dyn_args`
+ and `dyn_kwargs` has to be either `None` or a node that is used as
+ node for dynamic positional (``*args``) or keyword (``**kwargs``)
+ arguments.
+ """
+ fields = ('node', 'args', 'kwargs', 'dyn_args', 'dyn_kwargs')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if eval_ctx.volatile:
+ raise Impossible()
+ obj = self.node.as_const(eval_ctx)
+
+ # don't evaluate context functions
+ args = [x.as_const(eval_ctx) for x in self.args]
+ if isinstance(obj, _context_function_types):
+ if getattr(obj, 'contextfunction', False):
+ raise Impossible()
+ elif getattr(obj, 'evalcontextfunction', False):
+ args.insert(0, eval_ctx)
+ elif getattr(obj, 'environmentfunction', False):
+ args.insert(0, self.environment)
+
+ kwargs = dict(x.as_const(eval_ctx) for x in self.kwargs)
+ if self.dyn_args is not None:
+ try:
+ args.extend(self.dyn_args.as_const(eval_ctx))
+ except:
+ raise Impossible()
+ if self.dyn_kwargs is not None:
+ try:
+ kwargs.update(self.dyn_kwargs.as_const(eval_ctx))
+ except:
+ raise Impossible()
+ try:
+ return obj(*args, **kwargs)
+ except:
+ raise Impossible()
+
+
+class Getitem(Expr):
+ """Get an attribute or item from an expression and prefer the item."""
+ fields = ('node', 'arg', 'ctx')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if self.ctx != 'load':
+ raise Impossible()
+ try:
+ return self.environment.getitem(self.node.as_const(eval_ctx),
+ self.arg.as_const(eval_ctx))
+ except:
+ raise Impossible()
+
+ def can_assign(self):
+ return False
+
+
+class Getattr(Expr):
+ """Get an attribute or item from an expression that is a ascii-only
+ bytestring and prefer the attribute.
+ """
+ fields = ('node', 'attr', 'ctx')
+
+ def as_const(self, eval_ctx=None):
+ if self.ctx != 'load':
+ raise Impossible()
+ try:
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return self.environment.getattr(self.node.as_const(eval_ctx),
+ self.attr)
+ except:
+ raise Impossible()
+
+ def can_assign(self):
+ return False
+
+
+class Slice(Expr):
+ """Represents a slice object. This must only be used as argument for
+ :class:`Subscript`.
+ """
+ fields = ('start', 'stop', 'step')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ def const(obj):
+ if obj is None:
+ return None
+ return obj.as_const(eval_ctx)
+ return slice(const(self.start), const(self.stop), const(self.step))
+
+
+class Concat(Expr):
+ """Concatenates the list of expressions provided after converting them to
+ unicode.
+ """
+ fields = ('nodes',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return ''.join(unicode(x.as_const(eval_ctx)) for x in self.nodes)
+
+
+class Compare(Expr):
+ """Compares an expression with some other expressions. `ops` must be a
+ list of :class:`Operand`\s.
+ """
+ fields = ('expr', 'ops')
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ result = value = self.expr.as_const(eval_ctx)
+ try:
+ for op in self.ops:
+ new_value = op.expr.as_const(eval_ctx)
+ result = _cmpop_to_func[op.op](value, new_value)
+ value = new_value
+ except:
+ raise Impossible()
+ return result
+
+
+class Operand(Helper):
+ """Holds an operator and an expression."""
+ fields = ('op', 'expr')
+
+if __debug__:
+ Operand.__doc__ += '\nThe following operators are available: ' + \
+ ', '.join(sorted('``%s``' % x for x in set(_binop_to_func) |
+ set(_uaop_to_func) | set(_cmpop_to_func)))
+
+
+class Mul(BinExpr):
+ """Multiplies the left with the right node."""
+ operator = '*'
+
+
+class Div(BinExpr):
+ """Divides the left by the right node."""
+ operator = '/'
+
+
+class FloorDiv(BinExpr):
+ """Divides the left by the right node and truncates conver the
+ result into an integer by truncating.
+ """
+ operator = '//'
+
+
+class Add(BinExpr):
+ """Add the left to the right node."""
+ operator = '+'
+
+
+class Sub(BinExpr):
+ """Substract the right from the left node."""
+ operator = '-'
+
+
+class Mod(BinExpr):
+ """Left modulo right."""
+ operator = '%'
+
+
+class Pow(BinExpr):
+ """Left to the power of right."""
+ operator = '**'
+
+
+class And(BinExpr):
+ """Short circuited AND."""
+ operator = 'and'
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return self.left.as_const(eval_ctx) and self.right.as_const(eval_ctx)
+
+
+class Or(BinExpr):
+ """Short circuited OR."""
+ operator = 'or'
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return self.left.as_const(eval_ctx) or self.right.as_const(eval_ctx)
+
+
+class Not(UnaryExpr):
+ """Negate the expression."""
+ operator = 'not'
+
+
+class Neg(UnaryExpr):
+ """Make the expression negative."""
+ operator = '-'
+
+
+class Pos(UnaryExpr):
+ """Make the expression positive (noop for most expressions)"""
+ operator = '+'
+
+
+# Helpers for extensions
+
+
+class EnvironmentAttribute(Expr):
+ """Loads an attribute from the environment object. This is useful for
+ extensions that want to call a callback stored on the environment.
+ """
+ fields = ('name',)
+
+
+class ExtensionAttribute(Expr):
+ """Returns the attribute of an extension bound to the environment.
+ The identifier is the identifier of the :class:`Extension`.
+
+ This node is usually constructed by calling the
+ :meth:`~ambari_jinja2.ext.Extension.attr` method on an extension.
+ """
+ fields = ('identifier', 'name')
+
+
+class ImportedName(Expr):
+ """If created with an import name the import name is returned on node
+ access. For example ``ImportedName('cgi.escape')`` returns the `escape`
+ function from the cgi module on evaluation. Imports are optimized by the
+ compiler so there is no need to assign them to local variables.
+ """
+ fields = ('importname',)
+
+
+class InternalName(Expr):
+ """An internal name in the compiler. You cannot create these nodes
+ yourself but the parser provides a
+ :meth:`~ambari_jinja2.parser.Parser.free_identifier` method that creates
+ a new identifier for you. This identifier is not available from the
+ template and is not threated specially by the compiler.
+ """
+ fields = ('name',)
+
+ def __init__(self):
+ raise TypeError('Can\'t create internal names. Use the '
+ '`free_identifier` method on a parser.')
+
+
+class MarkSafe(Expr):
+ """Mark the wrapped expression as safe (wrap it as `Markup`)."""
+ fields = ('expr',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ return Markup(self.expr.as_const(eval_ctx))
+
+
+class MarkSafeIfAutoescape(Expr):
+ """Mark the wrapped expression as safe (wrap it as `Markup`) but
+ only if autoescaping is active.
+
+ .. versionadded:: 2.5
+ """
+ fields = ('expr',)
+
+ def as_const(self, eval_ctx=None):
+ eval_ctx = get_eval_context(self, eval_ctx)
+ if eval_ctx.volatile:
+ raise Impossible()
+ expr = self.expr.as_const(eval_ctx)
+ if eval_ctx.autoescape:
+ return Markup(expr)
+ return expr
+
+
+class ContextReference(Expr):
+ """Returns the current template context. It can be used like a
+ :class:`Name` node, with a ``'load'`` ctx and will return the
+ current :class:`~ambari_jinja2.runtime.Context` object.
+
+ Here an example that assigns the current template name to a
+ variable named `foo`::
+
+ Assign(Name('foo', ctx='store'),
+ Getattr(ContextReference(), 'name'))
+ """
+
+
+class Continue(Stmt):
+ """Continue a loop."""
+
+
+class Break(Stmt):
+ """Break a loop."""
+
+
+class Scope(Stmt):
+ """An artificial scope."""
+ fields = ('body',)
+
+
+class EvalContextModifier(Stmt):
+ """Modifies the eval context. For each option that should be modified,
+ a :class:`Keyword` has to be added to the :attr:`options` list.
+
+ Example to change the `autoescape` setting::
+
+ EvalContextModifier(options=[Keyword('autoescape', Const(True))])
+ """
+ fields = ('options',)
+
+
+class ScopedEvalContextModifier(EvalContextModifier):
+ """Modifies the eval context and reverts it later. Works exactly like
+ :class:`EvalContextModifier` but will only modify the
+ :class:`~ambari_jinja2.nodes.EvalContext` for nodes in the :attr:`body`.
+ """
+ fields = ('body',)
+
+
+# make sure nobody creates custom nodes
+def _failing_new(*args, **kwargs):
+ raise TypeError('can\'t create custom node types')
+NodeType.__new__ = staticmethod(_failing_new); del _failing_new
http://git-wip-us.apache.org/repos/asf/ambari/blob/7c3ea59f/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/optimizer.py
----------------------------------------------------------------------
diff --git a/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/optimizer.py b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/optimizer.py
new file mode 100644
index 0000000..b014396
--- /dev/null
+++ b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/optimizer.py
@@ -0,0 +1,68 @@
+# -*- coding: utf-8 -*-
+"""
+ ambari_jinja2.optimizer
+ ~~~~~~~~~~~~~~~~
+
+ The jinja optimizer is currently trying to constant fold a few expressions
+ and modify the AST in place so that it should be easier to evaluate it.
+
+ Because the AST does not contain all the scoping information and the
+ compiler has to find that out, we cannot do all the optimizations we
+ want. For example loop unrolling doesn't work because unrolled loops would
+ have a different scoping.
+
+ The solution would be a second syntax tree that has the scoping rules stored.
+
+ :copyright: (c) 2010 by the Jinja Team.
+ :license: BSD.
+"""
+from ambari_jinja2 import nodes
+from ambari_jinja2.visitor import NodeTransformer
+
+
+def optimize(node, environment):
+ """The context hint can be used to perform an static optimization
+ based on the context given."""
+ optimizer = Optimizer(environment)
+ return optimizer.visit(node)
+
+
+class Optimizer(NodeTransformer):
+
+ def __init__(self, environment):
+ self.environment = environment
+
+ def visit_If(self, node):
+ """Eliminate dead code."""
+ # do not optimize ifs that have a block inside so that it doesn't
+ # break super().
+ if node.find(nodes.Block) is not None:
+ return self.generic_visit(node)
+ try:
+ val = self.visit(node.test).as_const()
+ except nodes.Impossible:
+ return self.generic_visit(node)
+ if val:
+ body = node.body
+ else:
+ body = node.else_
+ result = []
+ for node in body:
+ result.extend(self.visit_list(node))
+ return result
+
+ def fold(self, node):
+ """Do constant folding."""
+ node = self.generic_visit(node)
+ try:
+ return nodes.Const.from_untrusted(node.as_const(),
+ lineno=node.lineno,
+ environment=self.environment)
+ except nodes.Impossible:
+ return node
+
+ visit_Add = visit_Sub = visit_Mul = visit_Div = visit_FloorDiv = \
+ visit_Pow = visit_Mod = visit_And = visit_Or = visit_Pos = visit_Neg = \
+ visit_Not = visit_Compare = visit_Getitem = visit_Getattr = visit_Call = \
+ visit_Filter = visit_Test = visit_CondExpr = fold
+ del fold
http://git-wip-us.apache.org/repos/asf/ambari/blob/7c3ea59f/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/parser.py
----------------------------------------------------------------------
diff --git a/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/parser.py b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/parser.py
new file mode 100644
index 0000000..a14c055
--- /dev/null
+++ b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/parser.py
@@ -0,0 +1,896 @@
+# -*- coding: utf-8 -*-
+"""
+ ambari_jinja2.parser
+ ~~~~~~~~~~~~~
+
+ Implements the template parser.
+
+ :copyright: (c) 2010 by the Jinja Team.
+ :license: BSD, see LICENSE for more details.
+"""
+from ambari_jinja2 import nodes
+from ambari_jinja2.exceptions import TemplateSyntaxError, TemplateAssertionError
+from ambari_jinja2.utils import next
+from ambari_jinja2.lexer import describe_token, describe_token_expr
+
+
+#: statements that callinto
+_statement_keywords = frozenset(['for', 'if', 'block', 'extends', 'print',
+ 'macro', 'include', 'from', 'import',
+ 'set'])
+_compare_operators = frozenset(['eq', 'ne', 'lt', 'lteq', 'gt', 'gteq'])
+
+
+class Parser(object):
+ """This is the central parsing class Jinja2 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(map(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:`~ambari_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()
+ self.stream.expect('assign')
+ expr = self.parse_tuple()
+ return nodes.Assign(target, expr, 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'))
+ token = next(self.stream)
+ if token.test('name:elif'):
+ new_node = nodes.If(lineno=self.stream.current.lineno)
+ node.else_ = [new_node]
+ node = new_node
+ continue
+ elif token.test('name:else'):
+ node.else_ = self.parse_statements(('name:endif',),
+ drop_needle=True)
+ else:
+ node.else_ = []
+ break
+ return result
+
+ 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 hypens, 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:
+ break
+ if not hasattr(node, 'with_context'):
+ node.with_context = False
+ self.stream.skip_if('comma')
+ 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())
+ 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):
+ """Parse an assignment target. As Jinja2 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 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_add()
+ 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_add()))
+ elif self.stream.skip_if('name:in'):
+ ops.append(nodes.Operand('in', self.parse_add()))
+ 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_add()))
+ else:
+ break
+ lineno = self.stream.current.lineno
+ if not ops:
+ return expr
+ return nodes.Compare(expr, ops, lineno=lineno)
+
+ def parse_add(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_sub()
+ while self.stream.current.type == 'add':
+ next(self.stream)
+ right = self.parse_sub()
+ left = nodes.Add(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_sub(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_concat()
+ while self.stream.current.type == 'sub':
+ next(self.stream)
+ right = self.parse_concat()
+ left = nodes.Sub(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_concat(self):
+ lineno = self.stream.current.lineno
+ args = [self.parse_mul()]
+ while self.stream.current.type == 'tilde':
+ next(self.stream)
+ args.append(self.parse_mul())
+ if len(args) == 1:
+ return args[0]
+ return nodes.Concat(args, lineno=lineno)
+
+ def parse_mul(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_div()
+ while self.stream.current.type == 'mul':
+ next(self.stream)
+ right = self.parse_div()
+ left = nodes.Mul(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_div(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_floordiv()
+ while self.stream.current.type == 'div':
+ next(self.stream)
+ right = self.parse_floordiv()
+ left = nodes.Div(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_floordiv(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_mod()
+ while self.stream.current.type == 'floordiv':
+ next(self.stream)
+ right = self.parse_mod()
+ left = nodes.FloorDiv(left, right, lineno=lineno)
+ lineno = self.stream.current.lineno
+ return left
+
+ def parse_mod(self):
+ lineno = self.stream.current.lineno
+ left = self.parse_pow()
+ while self.stream.current.type == 'mod':
+ next(self.stream)
+ right = self.parse_pow()
+ left = nodes.Mod(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:`~ambari_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:
+ parse = lambda: 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':
+ priority_on_attribute = False
+ 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', self.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:
+ ensure(dyn_args is None and dyn_kwargs is None)
+ if self.stream.current.type == 'name' and \
+ self.stream.look().type == 'assign':
+ key = self.stream.current.value
+ self.stream.skip(2)
+ value = self.parse_expression()
+ kwargs.append(nodes.Keyword(key, value,
+ lineno=value.lineno))
+ else:
+ ensure(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')
+ args = [self.parse_expression()]
+ 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
http://git-wip-us.apache.org/repos/asf/ambari/blob/7c3ea59f/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/runtime.py
----------------------------------------------------------------------
diff --git a/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/runtime.py b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/runtime.py
new file mode 100644
index 0000000..0830132
--- /dev/null
+++ b/ambari-common/src/main/python/ambari_jinja2/ambari_jinja2/runtime.py
@@ -0,0 +1,544 @@
+# -*- coding: utf-8 -*-
+"""
+ ambari_jinja2.runtime
+ ~~~~~~~~~~~~~~
+
+ Runtime helpers.
+
+ :copyright: (c) 2010 by the Jinja Team.
+ :license: BSD.
+"""
+import sys
+from itertools import chain, imap
+from ambari_jinja2.nodes import EvalContext, _context_function_types
+from ambari_jinja2.utils import Markup, partial, soft_unicode, escape, missing, \
+ concat, internalcode, next, object_type_repr
+from ambari_jinja2.exceptions import UndefinedError, TemplateRuntimeError, \
+ TemplateNotFound
+
+
+# these variables are exported to the template runtime
+__all__ = ['LoopContext', 'TemplateReference', 'Macro', 'Markup',
+ 'TemplateRuntimeError', 'missing', 'concat', 'escape',
+ 'markup_join', 'unicode_join', 'to_string', 'identity',
+ 'TemplateNotFound']
+
+#: the name of the function that is used to convert something into
+#: a string. 2to3 will adopt that automatically and the generated
+#: code can take advantage of it.
+to_string = unicode
+
+#: the identity function. Useful for certain things in the environment
+identity = lambda x: x
+
+
+def markup_join(seq):
+ """Concatenation that escapes if necessary and converts to unicode."""
+ buf = []
+ iterator = imap(soft_unicode, seq)
+ for arg in iterator:
+ buf.append(arg)
+ if hasattr(arg, '__html__'):
+ return Markup(u'').join(chain(buf, iterator))
+ return concat(buf)
+
+
+def unicode_join(seq):
+ """Simple args to unicode conversion and concatenation."""
+ return concat(imap(unicode, seq))
+
+
+def new_context(environment, template_name, blocks, vars=None,
+ shared=None, globals=None, locals=None):
+ """Internal helper to for context creation."""
+ if vars is None:
+ vars = {}
+ if shared:
+ parent = vars
+ else:
+ parent = dict(globals or (), **vars)
+ if locals:
+ # if the parent is shared a copy should be created because
+ # we don't want to modify the dict passed
+ if shared:
+ parent = dict(parent)
+ for key, value in locals.iteritems():
+ if key[:2] == 'l_' and value is not missing:
+ parent[key[2:]] = value
+ return Context(environment, parent, template_name, blocks)
+
+
+class TemplateReference(object):
+ """The `self` in templates."""
+
+ def __init__(self, context):
+ self.__context = context
+
+ def __getitem__(self, name):
+ blocks = self.__context.blocks[name]
+ wrap = self.__context.eval_ctx.autoescape and \
+ Markup or (lambda x: x)
+ return BlockReference(name, self.__context, blocks, 0)
+
+ def __repr__(self):
+ return '<%s %r>' % (
+ self.__class__.__name__,
+ self.__context.name
+ )
+
+
+class Context(object):
+ """The template context holds the variables of a template. It stores the
+ values passed to the template and also the names the template exports.
+ Creating instances is neither supported nor useful as it's created
+ automatically at various stages of the template evaluation and should not
+ be created by hand.
+
+ The context is immutable. Modifications on :attr:`parent` **must not**
+ happen and modifications on :attr:`vars` are allowed from generated
+ template code only. Template filters and global functions marked as
+ :func:`contextfunction`\s get the active context passed as first argument
+ and are allowed to access the context read-only.
+
+ The template context supports read only dict operations (`get`,
+ `keys`, `values`, `items`, `iterkeys`, `itervalues`, `iteritems`,
+ `__getitem__`, `__contains__`). Additionally there is a :meth:`resolve`
+ method that doesn't fail with a `KeyError` but returns an
+ :class:`Undefined` object for missing variables.
+ """
+ __slots__ = ('parent', 'vars', 'environment', 'eval_ctx', 'exported_vars',
+ 'name', 'blocks', '__weakref__')
+
+ def __init__(self, environment, parent, name, blocks):
+ self.parent = parent
+ self.vars = {}
+ self.environment = environment
+ self.eval_ctx = EvalContext(self.environment, name)
+ self.exported_vars = set()
+ self.name = name
+
+ # create the initial mapping of blocks. Whenever template inheritance
+ # takes place the runtime will update this mapping with the new blocks
+ # from the template.
+ self.blocks = dict((k, [v]) for k, v in blocks.iteritems())
+
+ def super(self, name, current):
+ """Render a parent block."""
+ try:
+ blocks = self.blocks[name]
+ index = blocks.index(current) + 1
+ blocks[index]
+ except LookupError:
+ return self.environment.undefined('there is no parent block '
+ 'called %r.' % name,
+ name='super')
+ return BlockReference(name, self, blocks, index)
+
+ def get(self, key, default=None):
+ """Returns an item from the template context, if it doesn't exist
+ `default` is returned.
+ """
+ try:
+ return self[key]
+ except KeyError:
+ return default
+
+ def resolve(self, key):
+ """Looks up a variable like `__getitem__` or `get` but returns an
+ :class:`Undefined` object with the name of the name looked up.
+ """
+ if key in self.vars:
+ return self.vars[key]
+ if key in self.parent:
+ return self.parent[key]
+ return self.environment.undefined(name=key)
+
+ def get_exported(self):
+ """Get a new dict with the exported variables."""
+ return dict((k, self.vars[k]) for k in self.exported_vars)
+
+ def get_all(self):
+ """Return a copy of the complete context as dict including the
+ exported variables.
+ """
+ return dict(self.parent, **self.vars)
+
+ @internalcode
+ def call(__self, __obj, *args, **kwargs):
+ """Call the callable with the arguments and keyword arguments
+ provided but inject the active context or environment as first
+ argument if the callable is a :func:`contextfunction` or
+ :func:`environmentfunction`.
+ """
+ if __debug__:
+ __traceback_hide__ = True
+ if isinstance(__obj, _context_function_types):
+ if getattr(__obj, 'contextfunction', 0):
+ args = (__self,) + args
+ elif getattr(__obj, 'evalcontextfunction', 0):
+ args = (__self.eval_ctx,) + args
+ elif getattr(__obj, 'environmentfunction', 0):
+ args = (__self.environment,) + args
+ try:
+ return __obj(*args, **kwargs)
+ except StopIteration:
+ return __self.environment.undefined('value was undefined because '
+ 'a callable raised a '
+ 'StopIteration exception')
+
+ def derived(self, locals=None):
+ """Internal helper function to create a derived context."""
+ context = new_context(self.environment, self.name, {},
+ self.parent, True, None, locals)
+ context.eval_ctx = self.eval_ctx
+ context.blocks.update((k, list(v)) for k, v in self.blocks.iteritems())
+ return context
+
+ def _all(meth):
+ proxy = lambda self: getattr(self.get_all(), meth)()
+ proxy.__doc__ = getattr(dict, meth).__doc__
+ proxy.__name__ = meth
+ return proxy
+
+ keys = _all('keys')
+ values = _all('values')
+ items = _all('items')
+
+ # not available on python 3
+ if hasattr(dict, 'iterkeys'):
+ iterkeys = _all('iterkeys')
+ itervalues = _all('itervalues')
+ iteritems = _all('iteritems')
+ del _all
+
+ def __contains__(self, name):
+ return name in self.vars or name in self.parent
+
+ def __getitem__(self, key):
+ """Lookup a variable or raise `KeyError` if the variable is
+ undefined.
+ """
+ item = self.resolve(key)
+ if isinstance(item, Undefined):
+ raise KeyError(key)
+ return item
+
+ def __repr__(self):
+ return '<%s %s of %r>' % (
+ self.__class__.__name__,
+ repr(self.get_all()),
+ self.name
+ )
+
+
+# register the context as mapping if possible
+try:
+ from collections import Mapping
+ Mapping.register(Context)
+except ImportError:
+ pass
+
+
+class BlockReference(object):
+ """One block on a template reference."""
+
+ def __init__(self, name, context, stack, depth):
+ self.name = name
+ self._context = context
+ self._stack = stack
+ self._depth = depth
+
+ @property
+ def super(self):
+ """Super the block."""
+ if self._depth + 1 >= len(self._stack):
+ return self._context.environment. \
+ undefined('there is no parent block called %r.' %
+ self.name, name='super')
+ return BlockReference(self.name, self._context, self._stack,
+ self._depth + 1)
+
+ @internalcode
+ def __call__(self):
+ rv = concat(self._stack[self._depth](self._context))
+ if self._context.eval_ctx.autoescape:
+ rv = Markup(rv)
+ return rv
+
+
+class LoopContext(object):
+ """A loop context for dynamic iteration."""
+
+ def __init__(self, iterable, recurse=None):
+ self._iterator = iter(iterable)
+ self._recurse = recurse
+ self.index0 = -1
+
+ # try to get the length of the iterable early. This must be done
+ # here because there are some broken iterators around where there
+ # __len__ is the number of iterations left (i'm looking at your
+ # listreverseiterator!).
+ try:
+ self._length = len(iterable)
+ except (TypeError, AttributeError):
+ self._length = None
+
+ def cycle(self, *args):
+ """Cycles among the arguments with the current loop index."""
+ if not args:
+ raise TypeError('no items for cycling given')
+ return args[self.index0 % len(args)]
+
+ first = property(lambda x: x.index0 == 0)
+ last = property(lambda x: x.index0 + 1 == x.length)
+ index = property(lambda x: x.index0 + 1)
+ revindex = property(lambda x: x.length - x.index0)
+ revindex0 = property(lambda x: x.length - x.index)
+
+ def __len__(self):
+ return self.length
+
+ def __iter__(self):
+ return LoopContextIterator(self)
+
+ @internalcode
+ def loop(self, iterable):
+ if self._recurse is None:
+ raise TypeError('Tried to call non recursive loop. Maybe you '
+ "forgot the 'recursive' modifier.")
+ return self._recurse(iterable, self._recurse)
+
+ # a nifty trick to enhance the error message if someone tried to call
+ # the the loop without or with too many arguments.
+ __call__ = loop
+ del loop
+
+ @property
+ def length(self):
+ if self._length is None:
+ # if was not possible to get the length of the iterator when
+ # the loop context was created (ie: iterating over a generator)
+ # we have to convert the iterable into a sequence and use the
+ # length of that.
+ iterable = tuple(self._iterator)
+ self._iterator = iter(iterable)
+ self._length = len(iterable) + self.index0 + 1
+ return self._length
+
+ def __repr__(self):
+ return '<%s %r/%r>' % (
+ self.__class__.__name__,
+ self.index,
+ self.length
+ )
+
+
+class LoopContextIterator(object):
+ """The iterator for a loop context."""
+ __slots__ = ('context',)
+
+ def __init__(self, context):
+ self.context = context
+
+ def __iter__(self):
+ return self
+
+ def next(self):
+ ctx = self.context
+ ctx.index0 += 1
+ return next(ctx._iterator), ctx
+
+
+class Macro(object):
+ """Wraps a macro function."""
+
+ def __init__(self, environment, func, name, arguments, defaults,
+ catch_kwargs, catch_varargs, caller):
+ self._environment = environment
+ self._func = func
+ self._argument_count = len(arguments)
+ self.name = name
+ self.arguments = arguments
+ self.defaults = defaults
+ self.catch_kwargs = catch_kwargs
+ self.catch_varargs = catch_varargs
+ self.caller = caller
+
+ @internalcode
+ def __call__(self, *args, **kwargs):
+ # try to consume the positional arguments
+ arguments = list(args[:self._argument_count])
+ off = len(arguments)
+
+ # if the number of arguments consumed is not the number of
+ # arguments expected we start filling in keyword arguments
+ # and defaults.
+ if off != self._argument_count:
+ for idx, name in enumerate(self.arguments[len(arguments):]):
+ try:
+ value = kwargs.pop(name)
+ except KeyError:
+ try:
+ value = self.defaults[idx - self._argument_count + off]
+ except IndexError:
+ value = self._environment.undefined(
+ 'parameter %r was not provided' % name, name=name)
+ arguments.append(value)
+
+ # it's important that the order of these arguments does not change
+ # if not also changed in the compiler's `function_scoping` method.
+ # the order is caller, keyword arguments, positional arguments!
+ if self.caller:
+ caller = kwargs.pop('caller', None)
+ if caller is None:
+ caller = self._environment.undefined('No caller defined',
+ name='caller')
+ arguments.append(caller)
+ if self.catch_kwargs:
+ arguments.append(kwargs)
+ elif kwargs:
+ raise TypeError('macro %r takes no keyword argument %r' %
+ (self.name, next(iter(kwargs))))
+ if self.catch_varargs:
+ arguments.append(args[self._argument_count:])
+ elif len(args) > self._argument_count:
+ raise TypeError('macro %r takes not more than %d argument(s)' %
+ (self.name, len(self.arguments)))
+ return self._func(*arguments)
+
+ def __repr__(self):
+ return '<%s %s>' % (
+ self.__class__.__name__,
+ self.name is None and 'anonymous' or repr(self.name)
+ )
+
+
+class Undefined(object):
+ """The default undefined type. This undefined type can be printed and
+ iterated over, but every other access will raise an :exc:`UndefinedError`:
+
+ >>> foo = Undefined(name='foo')
+ >>> str(foo)
+ ''
+ >>> not foo
+ True
+ >>> foo + 42
+ Traceback (most recent call last):
+ ...
+ UndefinedError: 'foo' is undefined
+ """
+ __slots__ = ('_undefined_hint', '_undefined_obj', '_undefined_name',
+ '_undefined_exception')
+
+ def __init__(self, hint=None, obj=missing, name=None, exc=UndefinedError):
+ self._undefined_hint = hint
+ self._undefined_obj = obj
+ self._undefined_name = name
+ self._undefined_exception = exc
+
+ @internalcode
+ def _fail_with_undefined_error(self, *args, **kwargs):
+ """Regular callback function for undefined objects that raises an
+ `UndefinedError` on call.
+ """
+ if self._undefined_hint is None:
+ if self._undefined_obj is missing:
+ hint = '%r is undefined' % self._undefined_name
+ elif not isinstance(self._undefined_name, basestring):
+ hint = '%s has no element %r' % (
+ object_type_repr(self._undefined_obj),
+ self._undefined_name
+ )
+ else:
+ hint = '%r has no attribute %r' % (
+ object_type_repr(self._undefined_obj),
+ self._undefined_name
+ )
+ else:
+ hint = self._undefined_hint
+ raise self._undefined_exception(hint)
+
+ __add__ = __radd__ = __mul__ = __rmul__ = __div__ = __rdiv__ = \
+ __truediv__ = __rtruediv__ = __floordiv__ = __rfloordiv__ = \
+ __mod__ = __rmod__ = __pos__ = __neg__ = __call__ = \
+ __getattr__ = __getitem__ = __lt__ = __le__ = __gt__ = __ge__ = \
+ __int__ = __float__ = __complex__ = __pow__ = __rpow__ = \
+ _fail_with_undefined_error
+
+ def __str__(self):
+ return unicode(self).encode('utf-8')
+
+ # unicode goes after __str__ because we configured 2to3 to rename
+ # __unicode__ to __str__. because the 2to3 tree is not designed to
+ # remove nodes from it, we leave the above __str__ around and let
+ # it override at runtime.
+ def __unicode__(self):
+ return u''
+
+ def __len__(self):
+ return 0
+
+ def __iter__(self):
+ if 0:
+ yield None
+
+ def __nonzero__(self):
+ return False
+
+ def __repr__(self):
+ return 'Undefined'
+
+
+class DebugUndefined(Undefined):
+ """An undefined that returns the debug info when printed.
+
+ >>> foo = DebugUndefined(name='foo')
+ >>> str(foo)
+ '{{ foo }}'
+ >>> not foo
+ True
+ >>> foo + 42
+ Traceback (most recent call last):
+ ...
+ UndefinedError: 'foo' is undefined
+ """
+ __slots__ = ()
+
+ def __unicode__(self):
+ if self._undefined_hint is None:
+ if self._undefined_obj is missing:
+ return u'{{ %s }}' % self._undefined_name
+ return '{{ no such element: %s[%r] }}' % (
+ object_type_repr(self._undefined_obj),
+ self._undefined_name
+ )
+ return u'{{ undefined value printed: %s }}' % self._undefined_hint
+
+
+class StrictUndefined(Undefined):
+ """An undefined that barks on print and iteration as well as boolean
+ tests and all kinds of comparisons. In other words: you can do nothing
+ with it except checking if it's defined using the `defined` test.
+
+ >>> foo = StrictUndefined(name='foo')
+ >>> str(foo)
+ Traceback (most recent call last):
+ ...
+ UndefinedError: 'foo' is undefined
+ >>> not foo
+ Traceback (most recent call last):
+ ...
+ UndefinedError: 'foo' is undefined
+ >>> foo + 42
+ Traceback (most recent call last):
+ ...
+ UndefinedError: 'foo' is undefined
+ """
+ __slots__ = ()
+ __iter__ = __unicode__ = __str__ = __len__ = __nonzero__ = __eq__ = \
+ __ne__ = __bool__ = Undefined._fail_with_undefined_error
+
+
+# remove remaining slots attributes, after the metaclass did the magic they
+# are unneeded and irritating as they contain wrong data for the subclasses.
+del Undefined.__slots__, DebugUndefined.__slots__, StrictUndefined.__slots__