# coding=utf-8
from collections import Iterable, Mapping
from flyforms.compat import string_base
UNSET = object() # the default mark for not set values
# Supported types for JSON encoding and decoding operations
jsonify_types = (bool, int, float, Iterable, Mapping, string_base)
[docs]class FrozenDict(Mapping):
"""
Immutable dictionary implementation
Base was copied from StackOverflow_ with some modifications
.. _StackOverflow: http://stackoverflow.com/questions/2703599/what-would-a-frozen-dict-be
"""
def __init__(self, *args, **kwargs):
self._d = dict(*args, **kwargs)
self._hash = None
def __iter__(self):
return iter(self._d)
def __len__(self):
return len(self._d)
def __getitem__(self, key):
return self._d[key]
def __hash__(self):
if self._hash is None:
self._hash = 0
for pair in self.iteritems():
self._hash ^= hash(pair)
return self._hash
def __repr__(self):
return str(self._d)
def __getattr__(self, item):
if item in self._d:
return self._d
if item == "_hash":
return self._hash
raise AttributeError()