Source

pypy / pypy / objspace / std / dicttype.py

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import sys

from pypy.interpreter import gateway
from pypy.interpreter.argument import Signature
from pypy.interpreter.baseobjspace import Wrappable
from pypy.interpreter.error import OperationError, operationerrfmt
from pypy.interpreter.mixedmodule import MixedModule
from pypy.objspace.std.model import registerimplementation
from pypy.objspace.std.register_all import register_all
from pypy.objspace.std.settype import set_typedef as settypedef
from pypy.objspace.std.stdtypedef import StdTypeDef, SMM
from pypy.rlib import rerased
from pypy.rlib.debug import mark_dict_non_null
from pypy.rlib.objectmodel import r_dict, we_are_translated, specialize


def _never_equal_to_string(space, w_lookup_type):
    """ Handles the case of a non string key lookup.
    Types that have a sane hash/eq function should allow us to return True
    directly to signal that the key is not in the dict in any case.
    XXX The types should provide such a flag. """

    # XXX there are many more types
    return (space.is_w(w_lookup_type, space.w_NoneType) or
            space.is_w(w_lookup_type, space.w_int) or
            space.is_w(w_lookup_type, space.w_bool) or
            space.is_w(w_lookup_type, space.w_float)
            )

class W_DictMultiObject(Wrappable):
    @staticmethod
    def allocate_and_init_instance(space, w_type=None, module=False,
                                   instance=False, classofinstance=None,
                                   strdict=False):

        if space.config.objspace.std.withcelldict and module:
            from pypy.objspace.std.celldict import ModuleDictStrategy
            assert w_type is None
            strategy = space.fromcache(ModuleDictStrategy)

        elif instance or strdict or module:
            assert w_type is None
            strategy = space.fromcache(StringDictStrategy)

        else:
            strategy = space.fromcache(EmptyDictStrategy)

        if w_type is None:
            w_type = space.w_dict
        storage = strategy.get_empty_storage()
        w_self = space.allocate_instance(W_DictMultiObject, w_type)
        W_DictMultiObject.__init__(w_self, space, strategy, storage)
        return w_self

    def __init__(self, space, strategy, storage):
        self.space = space
        self.strategy = strategy
        self.dstorage = storage

    def __repr__(w_self):
        """ representation for debugging purposes """
        return "%s(%s)" % (w_self.__class__.__name__, w_self.strategy)

    def unwrap(w_dict, space):
        result = {}
        items = w_dict.items()
        for w_pair in items:
            key, val = space.unwrap(w_pair)
            result[key] = val
        return result

    def missing_method(w_dict, space, w_key):
        if not space.is_w(space.type(w_dict), space.w_dict):
            w_missing = space.lookup(w_dict, "__missing__")
            if w_missing is None:
                return None
            return space.get_and_call_function(w_missing, w_dict, w_key)
        else:
            return None

    def initialize_content(w_self, list_pairs_w):
        for w_k, w_v in list_pairs_w:
            w_self.setitem(w_k, w_v)

    def descr__new__(space, w_subtype, __args__):
        return W_DictMultiObject.allocate_and_init_instance(space, w_subtype)

    def descr__init__(self, space, __args__):
        init_or_update(space, self, __args__, 'dict')

    def descr__getitem__(self, space, w_key):
        w_value = self.getitem(w_key)
        if w_value is not None:
            return w_value

        w_missing_item = self.missing_method(space, w_key)
        if w_missing_item is not None:
            return w_missing_item

        space.raise_key_error(w_key)

    def descr__setitem__(self, space, w_key, w_value):
        self.setitem(w_key, w_value)

    def descr__delitem__(self, space, w_key):
        try:
            self.delitem(w_key)
        except KeyError:
            space.raise_key_error(w_key)

    def descr__contains__(self, space, w_key):
        return space.newbool(self.getitem(w_key) is not None)

    def descr__len__(self, space):
        return space.wrap(self.length())

    def descr__reversed__(self, space):
        raise OperationError(space.w_TypeError, space.wrap('argument to reversed() must be a sequence'))

    def descr__repr__(self, space):
        ec = space.getexecutioncontext()
        w_currently_in_repr = ec._py_repr
        if w_currently_in_repr is None:
            w_currently_in_repr = ec._py_repr = space.newdict()
        return dictrepr(space, w_currently_in_repr, self)

    def descr__eq__(self, space, w_other):
        if not isinstance(w_other, W_DictMultiObject):
            return space.w_NotImplemented

        if space.is_w(self, w_other):
            return space.w_True

        if self.length() != w_other.length():
            return space.w_False
        iteratorimplementation = self.iter()
        while 1:
            w_key, w_val = iteratorimplementation.next()
            if w_key is None:
                break
            w_rightval = w_other.getitem(w_key)
            if w_rightval is None:
                return space.w_False
            if not space.eq_w(w_val, w_rightval):
                return space.w_False
        return space.w_True

    def descr__ne__(self, space, w_other):
        if not isinstance(w_other, W_DictMultiObject):
            return space.w_NotImplemented

        return space.not_(self.descr__eq__(space, w_other))

    def descr_items(self, space):
        """D.items() -> list of D's (key, value) pairs, as 2-tuples"""
        return space.newlist(self.items())

    def descr_keys(self, space):
        """D.keys() -> list of D's keys"""
        return space.newlist(self.keys())

    def descr_values(self, space):
        """D.values() -> list of D's values"""
        return space.newlist(self.values())

    def descr__iter__(self, space):
        return W_DictMultiIterObject(space, self.iter(), KEYSITER)

    def descr_iteritems(self, space):
        """D.iteritems() -> an iterator over the (key, value) items of D"""
        return W_DictMultiIterObject(space, self.iter(), ITEMSITER)

    def descr_iterkeys(self, space):
        """D.iterkeys() -> an iterator over the keys of D"""
        return W_DictMultiIterObject(space, self.iter(), KEYSITER)

    def descr_itervalues(self, space):
        """D.itervalues() -> an iterator over the values of D"""
        return W_DictMultiIterObject(space, self.iter(), VALUESITER)

    def descr_viewitems(self, space):
        """D.viewitems() -> a set-like object providing a view on D's items"""
        return W_DictViewItemsObject(space, self)

    def descr_viewkeys(self, space):
        """D.viewkeys() -> a set-like object providing a view on D's keys"""
        return W_DictViewKeysObject(space, self)

    def descr_viewvalues(self, space):
        """D.viewvalues() -> an object providing a view on D's values"""
        return W_DictViewValuesObject(space, self)

    def descr_update(self, space, __args__):
        """D.update(E, **F) -> None.  Update D from E and F: for k in E: D[k] = E[k]
        (if E has keys else: for (k, v) in E: D[k] = v) then: for k in F: D[k] = F[k]"""
        init_or_update(space, self, __args__, 'dict.update')

    def descr_setdefault(self, space, w_key, w_value=None):
        """D.setdefault(k[,d]) -> D.get(k,d), also set D[k]=d if k not in D"""
        return self.setdefault(w_key, w_value)

    def descr_popitem(self, space):
        """D.popitem() -> (k, v), remove and return some (key, value) pair as a
        2-tuple; but raise KeyError if D is empty"""
        try:
            w_key, w_value = self.popitem()
        except KeyError:
            raise OperationError(space.w_KeyError,
                                 space.wrap("popitem(): dictionary is empty"))
        return space.newtuple([w_key, w_value])

    def descr_pop(self, space, w_key, w_default=gateway.NoneNotWrapped):
        """D.pop(k[,d]) -> v, remove specified key and return the corresponding value
        If key is not found, d is returned if given, otherwise KeyError is raised"""
        w_item = self.getitem(w_key)
        if w_item is None:
            if w_default is not None:
                return w_default
            else:
                space.raise_key_error(w_key)
        else:
            self.delitem(w_key)
            return w_item

    def descr_clear(self):
        """D.clear() -> None.  Remove all items from D."""
        self.clear()

    def descr_get(self, space, w_key, w_default=None):
        """D.get(k[,d]) -> D[k] if k in D, else d.  d defaults to None."""
        w_value = self.getitem(w_key)
        if w_value is None:
            return w_default
        return w_value

    def descr_has_key(self, space, w_key):
        """D.has_key(k) -> True if D has a key k, else False"""
        return self.descr__contains__(space, w_key)

    def descr_copy(self, space):
        """D.copy() -> a shallow copy of D"""
        w_new = W_DictMultiObject.allocate_and_init_instance(space)
        update1_dict_dict(space, w_new, self)
        return w_new


def _add_indirections():
    dict_methods = "setitem setitem_str getitem \
                    getitem_str delitem length \
                    clear keys values \
                    items iter setdefault \
                    popitem".split()

    def make_method(method):
        def f(self, *args):
            return getattr(self.strategy, method)(self, *args)
        f.func_name = method
        return f

    for method in dict_methods:
        setattr(W_DictMultiObject, method, make_method(method))

_add_indirections()


KEYSITER = 0
ITEMSITER = 1
VALUESITER = 2

class W_DictMultiIterObject(Wrappable):
    _immutable_fields_ = ["iteratorimplementation", "itertype"]

    def __init__(w_self, space, iteratorimplementation, itertype):
        w_self.space = space
        w_self.iteratorimplementation = iteratorimplementation
        w_self.itertype = itertype

    def descr__iter__(self, space):
        return self

    def descr_next(self, space):
        iteratorimplementation = self.iteratorimplementation
        w_key, w_value = iteratorimplementation.next()
        if w_key is not None:
            itertype = self.itertype
            if itertype == KEYSITER:
                return w_key
            elif itertype == VALUESITER:
                return w_value
            elif itertype == ITEMSITER:
                return space.newtuple([w_key, w_value])
            else:
                assert 0, "should be unreachable"
        raise OperationError(space.w_StopIteration, space.w_None)

    def descr__reduce__(self, space):
        """
        This is a slightly special case of pickling.
        Since iteration over a dict is a bit hairy,
        we do the following:
        - create a clone of the dict iterator
        - run it to the original position
        - collect all remaining elements into a list
        At unpickling time, we just use that list
        and create an iterator on it.
        This is of course not the standard way.

        XXX to do: remove this __reduce__ method and do
        a registration with copy_reg, instead.
        """
        raise OperationError(
            space.w_TypeError,
            space.wrap("can't pickle dictionary-keyiterator objects"))

        w_mod    = space.getbuiltinmodule('_pickle_support')
        mod      = space.interp_w(MixedModule, w_mod)
        new_inst = mod.get('dictiter_surrogate_new')
        w_typeobj = space.gettypeobject(dictiter_typedef)

        # XXXXXX get that working again

        # we cannot call __init__ since we don't have the original dict
        if isinstance(w_self, W_DictIter_Keys):
            w_clone = space.allocate_instance(W_DictIter_Keys, w_typeobj)
        elif isinstance(w_self, W_DictIter_Values):
            w_clone = space.allocate_instance(W_DictIter_Values, w_typeobj)
        elif isinstance(w_self, W_DictIter_Items):
            w_clone = space.allocate_instance(W_DictIter_Items, w_typeobj)
        else:
            msg = "unsupported dictiter type '%s' during pickling" % (w_self, )
            raise OperationError(space.w_TypeError, space.wrap(msg))
        w_clone.space = space
        w_clone.content = w_self.content
        w_clone.len = w_self.len
        w_clone.pos = 0
        w_clone.setup_iterator()
        # spool until we have the same pos
        while w_clone.pos < w_self.pos:
            w_obj = w_clone.next_entry()
            w_clone.pos += 1
        stuff = [w_clone.next_entry() for i in range(w_clone.pos, w_clone.len)]
        w_res = space.newlist(stuff)
        tup      = [
            w_res
        ]
        w_ret = space.newtuple([new_inst, space.newtuple(tup)])
        return w_ret


class W_DictViewObject(Wrappable):
    def __init__(self, space, w_dict):
        self.w_dict = w_dict

    def descr__len__(self, space):
        return space.len(self.w_dict)

    def descr__repr__(self, space):
        w_seq = space.call_function(space.w_list, self)
        w_repr = space.repr(w_seq)
        return space.wrap("%s(%s)" % (space.type(self).getname(space),
                                      space.str_w(w_repr)))

class W_DictViewItemsObject(W_DictViewObject):
    def descr__iter__(self, space):
        return self.w_dict.descr_iteritems(space)

class W_DictViewKeysObject(W_DictViewObject):
    def descr__iter__(self, space):
        return self.w_dict.descr_iterkeys(space)

class W_DictViewValuesObject(W_DictViewObject):
    def descr__iter__(self, space):
        return self.w_dict.descr_itervalues(space)


class DictStrategy(object):
    def __init__(self, space):
        self.space = space

    def get_empty_storage(self):
        raise NotImplementedError

    def keys(self, w_dict):
        iterator = self.iter(w_dict)
        result = []
        while 1:
            w_key, w_value = iterator.next()
            if w_key is not None:
                result.append(w_key)
            else:
                return result

    def values(self, w_dict):
        iterator = self.iter(w_dict)
        result = []
        while 1:
            w_key, w_value = iterator.next()
            if w_value is not None:
                result.append(w_value)
            else:
                return result

    def items(self, w_dict):
        iterator = self.iter(w_dict)
        result = []
        while 1:
            w_key, w_value = iterator.next()
            if w_key is not None:
                result.append(self.space.newtuple([w_key, w_value]))
            else:
                return result

    def clear(self, w_dict):
        strategy = self.space.fromcache(EmptyDictStrategy)
        storage = strategy.get_empty_storage()
        w_dict.strategy = strategy
        w_dict.dstorage = storage

class IteratorImplementation(object):
    def __init__(self, space, implementation):
        self.space = space
        self.dictimplementation = implementation
        self.len = implementation.length()
        self.pos = 0

    def next(self):
        if self.dictimplementation is None:
            return None, None
        if self.len != self.dictimplementation.length():
            self.len = -1   # Make this error state sticky
            raise OperationError(self.space.w_RuntimeError,
                     self.space.wrap("dictionary changed size during iteration"))
        # look for the next entry
        if self.pos < self.len:
            result = self.next_entry()
            self.pos += 1
            return result
        # no more entries
        self.dictimplementation = None
        return None, None

    def next_entry(self):
        """ Purely abstract method
        """
        raise NotImplementedError

    def length(self):
        if self.dictimplementation is not None:
            return self.len - self.pos
        return 0

class _UnwrappedIteratorMixin(object):
    _mixin_ = True

    def __init__(self, space, strategy, dictimplementation):
        IteratorImplementation.__init__(self, space, dictimplementation)
        self.iterator = strategy.unerase(dictimplementation.dstorage).iteritems()

    def next_entry(self):
        # note that this 'for' loop only runs once, at most
        for w_key, w_value in self.iterator:
            return w_key, w_value
        else:
            return None, None

class _WrappedIteratorMixin(object):
    _mixin_ = True

    def __init__(self, space, strategy, dictimplementation):
        IteratorImplementation.__init__(self, space, dictimplementation)
        self.iterator = strategy.unerase(dictimplementation.dstorage).iteritems()

    def next_entry(self):
        # note that this 'for' loop only runs once, at most
        for key, w_value in self.iterator:
            return self.space.wrap(key), w_value
        else:
            return None, None

class EmptyDictStrategy(DictStrategy):

    erase, unerase = rerased.new_erasing_pair("empty")
    erase = staticmethod(erase)
    unerase = staticmethod(unerase)

    def get_empty_storage(self):
       return self.erase(None)

    def switch_to_correct_strategy(self, w_dict, w_key):
        withidentitydict = self.space.config.objspace.std.withidentitydict
        if type(w_key) is self.space.StringObjectCls:
            self.switch_to_string_strategy(w_dict)
            return
        w_type = self.space.type(w_key)
        if self.space.is_w(w_type, self.space.w_int):
            self.switch_to_int_strategy(w_dict)
        elif withidentitydict and w_type.compares_by_identity():
            self.switch_to_identity_strategy(w_dict)
        else:
            self.switch_to_object_strategy(w_dict)

    def switch_to_string_strategy(self, w_dict):
        strategy = self.space.fromcache(StringDictStrategy)
        storage = strategy.get_empty_storage()
        w_dict.strategy = strategy
        w_dict.dstorage = storage

    def switch_to_int_strategy(self, w_dict):
        strategy = self.space.fromcache(IntDictStrategy)
        storage = strategy.get_empty_storage()
        w_dict.strategy = strategy
        w_dict.dstorage = storage

    def switch_to_identity_strategy(self, w_dict):
        from pypy.objspace.std.identitydict import IdentityDictStrategy
        strategy = self.space.fromcache(IdentityDictStrategy)
        storage = strategy.get_empty_storage()
        w_dict.strategy = strategy
        w_dict.dstorage = storage

    def switch_to_object_strategy(self, w_dict):
        strategy = self.space.fromcache(ObjectDictStrategy)
        storage = strategy.get_empty_storage()
        w_dict.strategy = strategy
        w_dict.dstorage = storage

    def getitem(self, w_dict, w_key):
        #return w_value or None
        # in case the key is unhashable, try to hash it
        self.space.hash(w_key)
        # return None anyway
        return None

    def getitem_str(self, w_dict, key):
        #return w_value or None
        return None

    def setdefault(self, w_dict, w_key, w_default):
        # here the dict is always empty
        self.switch_to_correct_strategy(w_dict, w_key)
        w_dict.setitem(w_key, w_default)
        return w_default

    def setitem(self, w_dict, w_key, w_value):
        self.switch_to_correct_strategy(w_dict, w_key)
        w_dict.setitem(w_key, w_value)

    def setitem_str(self, w_dict, key, w_value):
        self.switch_to_string_strategy(w_dict)
        w_dict.setitem_str(key, w_value)

    def delitem(self, w_dict, w_key):
        # in case the key is unhashable, try to hash it
        self.space.hash(w_key)
        raise KeyError

    def length(self, w_dict):
        return 0

    def iter(self, w_dict):
        return EmptyIteratorImplementation(self.space, w_dict)

    def clear(self, w_dict):
        return

    def popitem(self, w_dict):
        raise KeyError

class EmptyIteratorImplementation(IteratorImplementation):
    def next(self):
        return (None, None)


class AbstractTypedStrategy(object):
    _mixin_ = True

    @staticmethod
    def erase(storage):
        raise NotImplementedError("abstract base class")

    @staticmethod
    def unerase(obj):
        raise NotImplementedError("abstract base class")

    def wrap(self, unwrapped):
        raise NotImplementedError

    def unwrap(self, wrapped):
        raise NotImplementedError

    def is_correct_type(self, w_obj):
        raise NotImplementedError("abstract base class")

    def get_empty_storage(self):
        raise NotImplementedError("abstract base class")

    def _never_equal_to(self, w_lookup_type):
        raise NotImplementedError("abstract base class")

    def setitem(self, w_dict, w_key, w_value):
        space = self.space
        if self.is_correct_type(w_key):
            self.unerase(w_dict.dstorage)[self.unwrap(w_key)] = w_value
            return
        else:
            self.switch_to_object_strategy(w_dict)
            w_dict.setitem(w_key, w_value)

    def setitem_str(self, w_dict, key, w_value):
        self.switch_to_object_strategy(w_dict)
        w_dict.setitem(self.space.wrap(key), w_value)

    def setdefault(self, w_dict, w_key, w_default):
        space = self.space
        if self.is_correct_type(w_key):
            return self.unerase(w_dict.dstorage).setdefault(self.unwrap(w_key), w_default)
        else:
            self.switch_to_object_strategy(w_dict)
            return w_dict.setdefault(w_key, w_default)

    def delitem(self, w_dict, w_key):
        space = self.space
        w_key_type = space.type(w_key)
        if self.is_correct_type(w_key):
            del self.unerase(w_dict.dstorage)[self.unwrap(w_key)]
            return
        else:
            self.switch_to_object_strategy(w_dict)
            return w_dict.delitem(w_key)

    def length(self, w_dict):
        return len(self.unerase(w_dict.dstorage))

    def getitem_str(self, w_dict, key):
        return self.getitem(w_dict, self.space.wrap(key))

    def getitem(self, w_dict, w_key):
        space = self.space
        if self.is_correct_type(w_key):
            return self.unerase(w_dict.dstorage).get(self.unwrap(w_key), None)
        elif self._never_equal_to(space.type(w_key)):
            return None
        else:
            self.switch_to_object_strategy(w_dict)
            return w_dict.getitem(w_key)

    def keys(self, w_dict):
        return [self.wrap(key) for key in self.unerase(w_dict.dstorage).iterkeys()]

    def values(self, w_dict):
        return self.unerase(w_dict.dstorage).values()

    def items(self, w_dict):
        space = self.space
        dict_w = self.unerase(w_dict.dstorage)
        return [space.newtuple([self.wrap(key), w_value])
                    for (key, w_value) in dict_w.iteritems()]

    def popitem(self, w_dict):
        key, value = self.unerase(w_dict.dstorage).popitem()
        return (self.wrap(key), value)

    def clear(self, w_dict):
        self.unerase(w_dict.dstorage).clear()

    def switch_to_object_strategy(self, w_dict):
        d = self.unerase(w_dict.dstorage)
        strategy = self.space.fromcache(ObjectDictStrategy)
        d_new = strategy.unerase(strategy.get_empty_storage())
        for key, value in d.iteritems():
            d_new[self.wrap(key)] = value
        w_dict.strategy = strategy
        w_dict.dstorage = strategy.erase(d_new)

class ObjectDictStrategy(AbstractTypedStrategy, DictStrategy):

    erase, unerase = rerased.new_erasing_pair("object")
    erase = staticmethod(erase)
    unerase = staticmethod(unerase)

    def wrap(self, unwrapped):
        return unwrapped

    def unwrap(self, wrapped):
        return wrapped

    def is_correct_type(self, w_obj):
        return True

    def get_empty_storage(self):
       new_dict = r_dict(self.space.eq_w, self.space.hash_w,
                         force_non_null=True)
       return self.erase(new_dict)

    def _never_equal_to(self, w_lookup_type):
        return False

    def iter(self, w_dict):
        return ObjectIteratorImplementation(self.space, self, w_dict)

    def keys(self, w_dict):
        return self.unerase(w_dict.dstorage).keys()

class ObjectIteratorImplementation(_UnwrappedIteratorMixin, IteratorImplementation):
    pass


class StringDictStrategy(AbstractTypedStrategy, DictStrategy):

    erase, unerase = rerased.new_erasing_pair("string")
    erase = staticmethod(erase)
    unerase = staticmethod(unerase)

    def wrap(self, unwrapped):
        return self.space.wrap(unwrapped)

    def unwrap(self, wrapped):
        return self.space.str_w(wrapped)

    def is_correct_type(self, w_obj):
        space = self.space
        return space.is_w(space.type(w_obj), space.w_str)

    def get_empty_storage(self):
        res = {}
        mark_dict_non_null(res)
        return self.erase(res)

    def _never_equal_to(self, w_lookup_type):
        return _never_equal_to_string(self.space, w_lookup_type)

    def setitem_str(self, w_dict, key, w_value):
        assert key is not None
        self.unerase(w_dict.dstorage)[key] = w_value

    def getitem(self, w_dict, w_key):
        space = self.space
        # -- This is called extremely often.  Hack for performance --
        if type(w_key) is space.StringObjectCls:
            return self.getitem_str(w_dict, w_key.unwrap(space))
        # -- End of performance hack --
        return AbstractTypedStrategy.getitem(self, w_dict, w_key)

    def getitem_str(self, w_dict, key):
        assert key is not None
        return self.unerase(w_dict.dstorage).get(key, None)

    def iter(self, w_dict):
        return StrIteratorImplementation(self.space, self, w_dict)

class StrIteratorImplementation(_WrappedIteratorMixin, IteratorImplementation):
    pass

class IntDictStrategy(AbstractTypedStrategy, DictStrategy):
    erase, unerase = rerased.new_erasing_pair("int")
    erase = staticmethod(erase)
    unerase = staticmethod(unerase)

    def wrap(self, unwrapped):
        return self.space.wrap(unwrapped)

    def unwrap(self, wrapped):
        return self.space.int_w(wrapped)

    def get_empty_storage(self):
        return self.erase({})

    def is_correct_type(self, w_obj):
        space = self.space
        return space.is_w(space.type(w_obj), space.w_int)

    def _never_equal_to(self, w_lookup_type):
        space = self.space
        # XXX there are many more types
        return (space.is_w(w_lookup_type, space.w_NoneType) or
                space.is_w(w_lookup_type, space.w_str) or
                space.is_w(w_lookup_type, space.w_unicode)
                )

    def iter(self, w_dict):
        return IntIteratorImplementation(self.space, self, w_dict)

class IntIteratorImplementation(_WrappedIteratorMixin, IteratorImplementation):
    pass


def descr_fromkeys(space, w_type, w_keys, w_fill=None):
    if w_fill is None:
        w_fill = space.w_None
    if space.is_w(w_type, space.w_dict):
        w_dict = W_DictMultiObject.allocate_and_init_instance(space, w_type)
        for w_key in space.listview(w_keys):
            w_dict.setitem(w_key, w_fill)
    else:
        w_dict = space.call_function(w_type)
        for w_key in space.listview(w_keys):
            space.setitem(w_dict, w_key, w_fill)
    return w_dict


app = gateway.applevel('''
    def dictrepr(currently_in_repr, d):
        if len(d) == 0:
            return "{}"
        dict_id = id(d)
        if dict_id in currently_in_repr:
            return '{...}'
        currently_in_repr[dict_id] = 1
        try:
            items = []
            # XXX for now, we cannot use iteritems() at app-level because
            #     we want a reasonable result instead of a RuntimeError
            #     even if the dict is mutated by the repr() in the loop.
            for k, v in dict.items(d):
                items.append(repr(k) + ": " + repr(v))
            return "{" +  ', '.join(items) + "}"
        finally:
            try:
                del currently_in_repr[dict_id]
            except:
                pass
''', filename=__file__)

dictrepr = app.interphook("dictrepr")


# ____________________________________________________________
init_signature = Signature(['seq_or_map'], None, 'kwargs')
init_defaults = [None]

def update1(space, w_dict, w_data):
    if space.findattr(w_data, space.wrap("keys")) is None:
        # no 'keys' method, so we assume it is a sequence of pairs
        for w_pair in space.listview(w_data):
            pair = space.fixedview(w_pair)
            if len(pair) != 2:
                raise OperationError(space.w_ValueError,
                             space.wrap("sequence of pairs expected"))
            w_key, w_value = pair
            w_dict.setitem(w_key, w_value)
    else:
        if isinstance(w_data, W_DictMultiObject):    # optimization case only
            update1_dict_dict(space, w_dict, w_data)
        else:
            # general case -- "for k in o.keys(): dict.__setitem__(d, k, o[k])"
            w_keys = space.call_method(w_data, "keys")
            for w_key in space.listview(w_keys):
                w_value = space.getitem(w_data, w_key)
                w_dict.setitem(w_key, w_value)

def update1_dict_dict(space, w_dict, w_data):
    iterator = w_data.iter()
    while 1:
        w_key, w_value = iterator.next()
        if w_key is None:
            break
        w_dict.setitem(w_key, w_value)

def init_or_update(space, w_dict, __args__, funcname):
    w_src, w_kwds = __args__.parse_obj(
            None, funcname,
            init_signature, # signature
            init_defaults)  # default argument
    if w_src is not None:
        update1(space, w_dict, w_src)
    if space.is_true(w_kwds):
        update1(space, w_dict, w_kwds)

### MULTIMETHOD STUFF

def characterize(space, w_a, w_b):
    """ (similar to CPython)
    returns the smallest key in acontent for which b's value is different or absent and this value """
    w_smallest_diff_a_key = None
    w_its_value = None
    iteratorimplementation = w_a.iter()
    while 1:
        w_key, w_val = iteratorimplementation.next()
        if w_key is None:
            break
        if w_smallest_diff_a_key is None or space.is_true(space.lt(w_key, w_smallest_diff_a_key)):
            w_bvalue = w_b.getitem(w_key)
            if w_bvalue is None:
                w_its_value = w_val
                w_smallest_diff_a_key = w_key
            else:
                if not space.eq_w(w_val, w_bvalue):
                    w_its_value = w_val
                    w_smallest_diff_a_key = w_key
    return w_smallest_diff_a_key, w_its_value

def lt__DictMulti_DictMulti(space, w_left, w_right):
    # Different sizes, no problem
    if w_left.length() < w_right.length():
        return space.w_True
    if w_left.length() > w_right.length():
        return space.w_False

    # Same size
    w_leftdiff, w_leftval = characterize(space, w_left, w_right)
    if w_leftdiff is None:
        return space.w_False
    w_rightdiff, w_rightval = characterize(space, w_right, w_left)
    if w_rightdiff is None:
        # w_leftdiff is not None, w_rightdiff is None
        return space.w_True
    w_res = space.lt(w_leftdiff, w_rightdiff)
    if (not space.is_true(w_res) and
        space.eq_w(w_leftdiff, w_rightdiff) and
        w_rightval is not None):
        w_res = space.lt(w_leftval, w_rightval)
    return w_res

def all_contained_in(space, w_dictview, w_otherview):
    w_iter = space.iter(w_dictview)
    assert isinstance(w_iter, W_DictMultiIterObject)

    while True:
        try:
            w_item = space.next(w_iter)
        except OperationError, e:
            if not e.match(space, space.w_StopIteration):
                raise
            break
        if not space.is_true(space.contains(w_otherview, w_item)):
            return space.w_False

    return space.w_True

def eq__DictViewKeys_DictViewKeys(space, w_dictview, w_otherview):
    if space.eq_w(space.len(w_dictview), space.len(w_otherview)):
        return all_contained_in(space, w_dictview, w_otherview)
    return space.w_False
eq__DictViewKeys_settypedef = eq__DictViewKeys_DictViewKeys

eq__DictViewKeys_DictViewItems = eq__DictViewKeys_DictViewKeys
eq__DictViewItems_DictViewItems = eq__DictViewKeys_DictViewKeys
eq__DictViewItems_settypedef = eq__DictViewItems_DictViewItems

def and__DictViewKeys_DictViewKeys(space, w_dictview, w_otherview):
    w_set = space.call_function(space.w_set, w_dictview)
    space.call_method(w_set, "intersection_update", w_otherview)
    return w_set
and__DictViewKeys_settypedef = and__DictViewKeys_DictViewKeys
and__DictViewItems_DictViewItems = and__DictViewKeys_DictViewKeys
and__DictViewItems_settypedef = and__DictViewKeys_DictViewKeys

def or__DictViewKeys_DictViewKeys(space, w_dictview, w_otherview):
    w_set = space.call_function(space.w_set, w_dictview)
    space.call_method(w_set, "update", w_otherview)
    return w_set
or__DictViewKeys_settypedef = or__DictViewKeys_DictViewKeys
or__DictViewItems_DictViewItems = or__DictViewKeys_DictViewKeys
or__DictViewItems_settypedef = or__DictViewKeys_DictViewKeys

def xor__DictViewKeys_DictViewKeys(space, w_dictview, w_otherview):
    w_set = space.call_function(space.w_set, w_dictview)
    space.call_method(w_set, "symmetric_difference_update", w_otherview)
    return w_set
xor__DictViewKeys_settypedef = xor__DictViewKeys_DictViewKeys
xor__DictViewItems_DictViewItems = xor__DictViewKeys_DictViewKeys
xor__DictViewItems_settypedef = xor__DictViewKeys_DictViewKeys

# ____________________________________________________________

W_DictMultiObject.typedef = StdTypeDef("dict",
    __doc__ = '''dict() -> new empty dictionary.
dict(mapping) -> new dictionary initialized from a mapping object\'s
    (key, value) pairs.
dict(seq) -> new dictionary initialized as if via:
    d = {}
    for k, v in seq:
        d[k] = v
dict(**kwargs) -> new dictionary initialized with the name=value pairs
    in the keyword argument list.  For example:  dict(one=1, two=2)''',
    __new__ = gateway.interp2app(W_DictMultiObject.descr__new__.im_func),
    fromkeys = gateway.interp2app(descr_fromkeys, as_classmethod=True),
    __init__ = gateway.interp2app(W_DictMultiObject.descr__init__),

    __hash__ = None,
    __repr__ = gateway.interp2app(W_DictMultiObject.descr__repr__),
    __reversed__ = gateway.interp2app(W_DictMultiObject.descr__reversed__),
    __eq__ = gateway.interp2app(W_DictMultiObject.descr__eq__),
    __ne__ = gateway.interp2app(W_DictMultiObject.descr__ne__),

    __len__ = gateway.interp2app(W_DictMultiObject.descr__len__),
    __getitem__ = gateway.interp2app(W_DictMultiObject.descr__getitem__),
    __setitem__ = gateway.interp2app(W_DictMultiObject.descr__setitem__),
    __delitem__ = gateway.interp2app(W_DictMultiObject.descr__delitem__),
    __contains__ = gateway.interp2app(W_DictMultiObject.descr__contains__),
    __iter__ = gateway.interp2app(W_DictMultiObject.descr__iter__),

    items = gateway.interp2app(W_DictMultiObject.descr_items),
    keys = gateway.interp2app(W_DictMultiObject.descr_keys),
    values = gateway.interp2app(W_DictMultiObject.descr_values),

    iteritems = gateway.interp2app(W_DictMultiObject.descr_iteritems),
    iterkeys = gateway.interp2app(W_DictMultiObject.descr_iterkeys),
    itervalues = gateway.interp2app(W_DictMultiObject.descr_itervalues),

    viewitems = gateway.interp2app(W_DictMultiObject.descr_viewitems),
    viewkeys = gateway.interp2app(W_DictMultiObject.descr_viewkeys),
    viewvalues = gateway.interp2app(W_DictMultiObject.descr_viewvalues),

    update = gateway.interp2app(W_DictMultiObject.descr_update),
    setdefault = gateway.interp2app(W_DictMultiObject.descr_setdefault),
    popitem = gateway.interp2app(W_DictMultiObject.descr_popitem),
    pop = gateway.interp2app(W_DictMultiObject.descr_pop),
    clear = gateway.interp2app(W_DictMultiObject.descr_clear),

    get = gateway.interp2app(W_DictMultiObject.descr_get),
    has_key = gateway.interp2app(W_DictMultiObject.descr_has_key),
    copy = gateway.interp2app(W_DictMultiObject.descr_copy),
)



# ____________________________________________________________

W_DictMultiIterObject.typedef = StdTypeDef("dictionaryiterator",
    __iter__ = gateway.interp2app(W_DictMultiIterObject.descr__iter__),
    __reduce__ = gateway.interp2app(W_DictMultiIterObject.descr__reduce__),
    next = gateway.interp2app(W_DictMultiIterObject.descr_next),
)

# ____________________________________________________________
# Dict views

W_DictViewKeysObject.typedef = StdTypeDef("dict_keys",
    __len__ = gateway.interp2app(W_DictViewKeysObject.descr__len__),
    __iter__ = gateway.interp2app(W_DictViewKeysObject.descr__iter__),
    __repr__ = gateway.interp2app(W_DictViewKeysObject.descr__repr__),
)

W_DictViewItemsObject.typedef = StdTypeDef("dict_items",
    __len__ = gateway.interp2app(W_DictViewItemsObject.descr__len__),
    __iter__ = gateway.interp2app(W_DictViewItemsObject.descr__iter__),
    __repr__ = gateway.interp2app(W_DictViewItemsObject.descr__repr__),
)

W_DictViewValuesObject.typedef = StdTypeDef("dict_values",
    __len__ = gateway.interp2app(W_DictViewValuesObject.descr__len__),
    __iter__ = gateway.interp2app(W_DictViewValuesObject.descr__iter__),
    __repr__ = gateway.interp2app(W_DictViewValuesObject.descr__repr__),
)


registerimplementation(W_DictMultiObject)
registerimplementation(W_DictMultiIterObject)
register_all(vars(), sys.modules[__name__])