1 files changed, 330 insertions, 0 deletions
diff --git a/third_party/python/pyrsistent/pyrsistent/_field_common.py b/third_party/python/pyrsistent/pyrsistent/_field_common.py
new file mode 100644
index 0000000000..ca1cccd43c
--- /dev/null
+++ b/third_party/python/pyrsistent/pyrsistent/_field_common.py
@@ -0,0 +1,330 @@
+import six
+import sys
+
+from pyrsistent._checked_types import (
+    CheckedPMap,
+    CheckedPSet,
+    CheckedPVector,
+    CheckedType,
+    InvariantException,
+    _restore_pickle,
+    get_type,
+    maybe_parse_user_type,
+    maybe_parse_many_user_types,
+)
+from pyrsistent._checked_types import optional as optional_type
+from pyrsistent._checked_types import wrap_invariant
+import inspect
+
+PY2 = sys.version_info[0] < 3
+
+
+def set_fields(dct, bases, name):
+    dct[name] = dict(sum([list(b.__dict__.get(name, {}).items()) for b in bases], []))
+
+    for k, v in list(dct.items()):
+        if isinstance(v, _PField):
+            dct[name][k] = v
+            del dct[k]
+
+
+def check_global_invariants(subject, invariants):
+    error_codes = tuple(error_code for is_ok, error_code in
+                        (invariant(subject) for invariant in invariants) if not is_ok)
+    if error_codes:
+        raise InvariantException(error_codes, (), 'Global invariant failed')
+
+
+def serialize(serializer, format, value):
+    if isinstance(value, CheckedType) and serializer is PFIELD_NO_SERIALIZER:
+        return value.serialize(format)
+
+    return serializer(format, value)
+
+
+def check_type(destination_cls, field, name, value):
+    if field.type and not any(isinstance(value, get_type(t)) for t in field.type):
+        actual_type = type(value)
+        message = "Invalid type for field {0}.{1}, was {2}".format(destination_cls.__name__, name, actual_type.__name__)
+        raise PTypeError(destination_cls, name, field.type, actual_type, message)
+
+
+def is_type_cls(type_cls, field_type):
+    if type(field_type) is set:
+        return True
+    types = tuple(field_type)
+    if len(types) == 0:
+        return False
+    return issubclass(get_type(types[0]), type_cls)
+
+
+def is_field_ignore_extra_complaint(type_cls, field, ignore_extra):
+    # ignore_extra param has default False value, for speed purpose no need to propagate False
+    if not ignore_extra:
+        return False
+
+    if not is_type_cls(type_cls, field.type):
+        return False
+
+    if PY2:
+        return 'ignore_extra' in inspect.getargspec(field.factory).args
+    else:
+        return 'ignore_extra' in inspect.signature(field.factory).parameters
+
+
+
+class _PField(object):
+    __slots__ = ('type', 'invariant', 'initial', 'mandatory', '_factory', 'serializer')
+
+    def __init__(self, type, invariant, initial, mandatory, factory, serializer):
+        self.type = type
+        self.invariant = invariant
+        self.initial = initial
+        self.mandatory = mandatory
+        self._factory = factory
+        self.serializer = serializer
+
+    @property
+    def factory(self):
+        # If no factory is specified and the type is another CheckedType use the factory method of that CheckedType
+        if self._factory is PFIELD_NO_FACTORY and len(self.type) == 1:
+            typ = get_type(tuple(self.type)[0])
+            if issubclass(typ, CheckedType):
+                return typ.create
+
+        return self._factory
+
+PFIELD_NO_TYPE = ()
+PFIELD_NO_INVARIANT = lambda _: (True, None)
+PFIELD_NO_FACTORY = lambda x: x
+PFIELD_NO_INITIAL = object()
+PFIELD_NO_SERIALIZER = lambda _, value: value
+
+
+def field(type=PFIELD_NO_TYPE, invariant=PFIELD_NO_INVARIANT, initial=PFIELD_NO_INITIAL,
+          mandatory=False, factory=PFIELD_NO_FACTORY, serializer=PFIELD_NO_SERIALIZER):
+    """
+    Field specification factory for :py:class:`PRecord`.
+
+    :param type: a type or iterable with types that are allowed for this field
+    :param invariant: a function specifying an invariant that must hold for the field
+    :param initial: value of field if not specified when instantiating the record
+    :param mandatory: boolean specifying if the field is mandatory or not
+    :param factory: function called when field is set.
+    :param serializer: function that returns a serialized version of the field
+    """
+
+    # NB: We have to check this predicate separately from the predicates in
+    # `maybe_parse_user_type` et al. because this one is related to supporting
+    # the argspec for `field`, while those are related to supporting the valid
+    # ways to specify types.
+
+    # Multiple types must be passed in one of the following containers. Note
+    # that a type that is a subclass of one of these containers, like a
+    # `collections.namedtuple`, will work as expected, since we check
+    # `isinstance` and not `issubclass`.
+    if isinstance(type, (list, set, tuple)):
+        types = set(maybe_parse_many_user_types(type))
+    else:
+        types = set(maybe_parse_user_type(type))
+
+    invariant_function = wrap_invariant(invariant) if invariant != PFIELD_NO_INVARIANT and callable(invariant) else invariant
+    field = _PField(type=types, invariant=invariant_function, initial=initial,
+                    mandatory=mandatory, factory=factory, serializer=serializer)
+
+    _check_field_parameters(field)
+
+    return field
+
+
+def _check_field_parameters(field):
+    for t in field.type:
+        if not isinstance(t, type) and not isinstance(t, six.string_types):
+            raise TypeError('Type parameter expected, not {0}'.format(type(t)))
+
+    if field.initial is not PFIELD_NO_INITIAL and \
+            not callable(field.initial) and \
+            field.type and not any(isinstance(field.initial, t) for t in field.type):
+        raise TypeError('Initial has invalid type {0}'.format(type(field.initial)))
+
+    if not callable(field.invariant):
+        raise TypeError('Invariant must be callable')
+
+    if not callable(field.factory):
+        raise TypeError('Factory must be callable')
+
+    if not callable(field.serializer):
+        raise TypeError('Serializer must be callable')
+
+
+class PTypeError(TypeError):
+    """
+    Raised when trying to assign a value with a type that doesn't match the declared type.
+
+    Attributes:
+    source_class -- The class of the record
+    field -- Field name
+    expected_types  -- Types allowed for the field
+    actual_type -- The non matching type
+    """
+    def __init__(self, source_class, field, expected_types, actual_type, *args, **kwargs):
+        super(PTypeError, self).__init__(*args, **kwargs)
+        self.source_class = source_class
+        self.field = field
+        self.expected_types = expected_types
+        self.actual_type = actual_type
+
+
+SEQ_FIELD_TYPE_SUFFIXES = {
+    CheckedPVector: "PVector",
+    CheckedPSet: "PSet",
+}
+
+# Global dictionary to hold auto-generated field types: used for unpickling
+_seq_field_types = {}
+
+def _restore_seq_field_pickle(checked_class, item_type, data):
+    """Unpickling function for auto-generated PVec/PSet field types."""
+    type_ = _seq_field_types[checked_class, item_type]
+    return _restore_pickle(type_, data)
+
+def _types_to_names(types):
+    """Convert a tuple of types to a human-readable string."""
+    return "".join(get_type(typ).__name__.capitalize() for typ in types)
+
+def _make_seq_field_type(checked_class, item_type):
+    """Create a subclass of the given checked class with the given item type."""
+    type_ = _seq_field_types.get((checked_class, item_type))
+    if type_ is not None:
+        return type_
+
+    class TheType(checked_class):
+        __type__ = item_type
+
+        def __reduce__(self):
+            return (_restore_seq_field_pickle,
+                    (checked_class, item_type, list(self)))
+
+    suffix = SEQ_FIELD_TYPE_SUFFIXES[checked_class]
+    TheType.__name__ = _types_to_names(TheType._checked_types) + suffix
+    _seq_field_types[checked_class, item_type] = TheType
+    return TheType
+
+def _sequence_field(checked_class, item_type, optional, initial):
+    """
+    Create checked field for either ``PSet`` or ``PVector``.
+
+    :param checked_class: ``CheckedPSet`` or ``CheckedPVector``.
+    :param item_type: The required type for the items in the set.
+    :param optional: If true, ``None`` can be used as a value for
+        this field.
+    :param initial: Initial value to pass to factory.
+
+    :return: A ``field`` containing a checked class.
+    """
+    TheType = _make_seq_field_type(checked_class, item_type)
+
+    if optional:
+        def factory(argument, _factory_fields=None, ignore_extra=False):
+            if argument is None:
+                return None
+            else:
+                return TheType.create(argument, _factory_fields=_factory_fields, ignore_extra=ignore_extra)
+    else:
+        factory = TheType.create
+
+    return field(type=optional_type(TheType) if optional else TheType,
+                 factory=factory, mandatory=True,
+                 initial=factory(initial))
+
+
+def pset_field(item_type, optional=False, initial=()):
+    """
+    Create checked ``PSet`` field.
+
+    :param item_type: The required type for the items in the set.
+    :param optional: If true, ``None`` can be used as a value for
+        this field.
+    :param initial: Initial value to pass to factory if no value is given
+        for the field.
+
+    :return: A ``field`` containing a ``CheckedPSet`` of the given type.
+    """
+    return _sequence_field(CheckedPSet, item_type, optional,
+                           initial)
+
+
+def pvector_field(item_type, optional=False, initial=()):
+    """
+    Create checked ``PVector`` field.
+
+    :param item_type: The required type for the items in the vector.
+    :param optional: If true, ``None`` can be used as a value for
+        this field.
+    :param initial: Initial value to pass to factory if no value is given
+        for the field.
+
+    :return: A ``field`` containing a ``CheckedPVector`` of the given type.
+    """
+    return _sequence_field(CheckedPVector, item_type, optional,
+                           initial)
+
+
+_valid = lambda item: (True, "")
+
+
+# Global dictionary to hold auto-generated field types: used for unpickling
+_pmap_field_types = {}
+
+def _restore_pmap_field_pickle(key_type, value_type, data):
+    """Unpickling function for auto-generated PMap field types."""
+    type_ = _pmap_field_types[key_type, value_type]
+    return _restore_pickle(type_, data)
+
+def _make_pmap_field_type(key_type, value_type):
+    """Create a subclass of CheckedPMap with the given key and value types."""
+    type_ = _pmap_field_types.get((key_type, value_type))
+    if type_ is not None:
+        return type_
+
+    class TheMap(CheckedPMap):
+        __key_type__ = key_type
+        __value_type__ = value_type
+
+        def __reduce__(self):
+            return (_restore_pmap_field_pickle,
+                    (self.__key_type__, self.__value_type__, dict(self)))
+
+    TheMap.__name__ = "{0}To{1}PMap".format(
+        _types_to_names(TheMap._checked_key_types),
+        _types_to_names(TheMap._checked_value_types))
+    _pmap_field_types[key_type, value_type] = TheMap
+    return TheMap
+
+
+def pmap_field(key_type, value_type, optional=False, invariant=PFIELD_NO_INVARIANT):
+    """
+    Create a checked ``PMap`` field.
+
+    :param key: The required type for the keys of the map.
+    :param value: The required type for the values of the map.
+    :param optional: If true, ``None`` can be used as a value for
+        this field.
+    :param invariant: Pass-through to ``field``.
+
+    :return: A ``field`` containing a ``CheckedPMap``.
+    """
+    TheMap = _make_pmap_field_type(key_type, value_type)
+
+    if optional:
+        def factory(argument):
+            if argument is None:
+                return None
+            else:
+                return TheMap.create(argument)
+    else:
+        factory = TheMap.create
+
+    return field(mandatory=True, initial=TheMap(),
+                 type=optional_type(TheMap) if optional else TheMap,
+                 factory=factory, invariant=invariant)