slice page working. added temporarily core and util classes from manifold core

[myslice.git] / manifold / util / frozendict.py

diff --git a/manifold/util/frozendict.py b/manifold/util/frozendict.py
new file mode 100644 (file)
index 0000000..32902cb
--- /dev/null
+++ b/manifold/util/frozendict.py
@@ -0,0 +1,47 @@
+import copy
+
+class frozendict(dict):
+    def _blocked_attribute(obj):
+        raise AttributeError, "A frozendict cannot be modified."
+    _blocked_attribute = property(_blocked_attribute)
+
+    __delitem__ = __setitem__ = clear = _blocked_attribute
+    pop = popitem = setdefault = update = _blocked_attribute
+
+    def __new__(cls, *args, **kw):
+        new = dict.__new__(cls)
+
+        args_ = []
+        for arg in args:
+            if isinstance(arg, dict):
+                arg = copy.copy(arg)
+                for k, v in arg.items():
+                    if isinstance(v, dict):
+                        arg[k] = frozendict(v)
+                    elif isinstance(v, list):
+                        v_ = list()
+                        for elm in v:
+                            if isinstance(elm, dict):
+                                v_.append( frozendict(elm) )
+                            else:
+                                v_.append( elm )
+                        arg[k] = tuple(v_)
+                args_.append( arg )
+            else:
+                args_.append( arg )
+
+        dict.__init__(new, *args_, **kw)
+        return new
+
+    def __init__(self, *args, **kw):
+        pass
+
+    def __hash__(self):
+        try:
+            return self._cached_hash
+        except AttributeError:
+            h = self._cached_hash = hash(tuple(sorted(self.items())))
+            return h
+
+    def __repr__(self):
+        return "frozendict(%s)" % dict.__repr__(self)