def list_type(cls):
"""
Return an ASTNode subclass that represent a list of "cls".
"""
element_type = cls
def add_to_context(cls):
if cls in get_context().types:
return
get_context().types.add(cls)
get_context().list_types.add(cls.element_type())
# Make sure the type this list contains is already declared
cls.element_type().add_to_context()
return type(
'{}ListType'.format(element_type.name()),
(StructMetaClass.root_grammar_class, ), {
'is_ptr':
True,
'name':
classmethod(
lambda cls: names.Name('List') + cls.element_type().name()
),
'add_to_context':
classmethod(add_to_context),
'nullexpr':
classmethod(lambda cls: null_constant()),
'is_list_type':
True,
'is_collection':
classmethod(lambda cls: True),
'element_type':
classmethod(lambda cls: element_type),
})
def nullexpr(cls):
"""
Return a value that can be considered as "null" for this AST node type.
It indicates the absence of AST node.
"""
if cls.is_ptr:
return null_constant()
else:
return names.Name('No') + cls.name()
def nullexpr(cls):
null_constant()
