more tweaks

nifty5/domain_tuple.py

@@ -68,8 +68,6 @@ class DomainTuple(object):
         """
         if isinstance(domain, DomainTuple):
             return domain
-        if isinstance(domain, dict):
-            return domain
         domain = DomainTuple._parse_domain(domain)
         obj = DomainTuple._tupleCache.get(domain)
         if obj is not None:
@@ -126,7 +124,8 @@ class DomainTuple(object):
         return self._dom.__hash__()
 
     def __eq__(self, x):
-        if not isinstance(x, DomainTuple):
+        if self is x:
+            return True
         x = DomainTuple.make(x)
         return self is x
 
@@ -140,9 +139,10 @@ class DomainTuple(object):
         return self.__eq__(x)
 
     def unitedWith(self, x):
-        if not isinstance(x, DomainTuple):
+        if self is x:
+            return self
         x = DomainTuple.make(x)
-        if self != x:
+        if self is not x:
             raise ValueError("domain mismatch")
         return self
 

nifty5/multi/multi_domain.py

@@ -75,7 +75,8 @@ class MultiDomain(frozendict):
         return obj
 
     def __eq__(self, x):
-        if not isinstance(x, MultiDomain):
+        if self is x:
+            return True
         x = MultiDomain.make(x)
         return self is x
 
@@ -86,20 +87,22 @@ class MultiDomain(frozendict):
         return super(MultiDomain, self).__hash__()
 
     def compatibleTo(self, x):
-        if not isinstance(x, MultiDomain):
+        if self is x:
+            return True
         x = MultiDomain.make(x)
         if (self, x) in MultiDomain._compatCache:
             return True
         commonKeys = set(self.keys()) & set(x.keys())
         for key in commonKeys:
-            if self[key] != x[key]:
+            if self[key] is not x[key]:
                 return False
         MultiDomain._compatCache.add((self, x))
         MultiDomain._compatCache.add((x, self))
         return True
 
     def subsetOf(self, x):
-        if not isinstance(x, MultiDomain):
+        if self is x:
+            return True
         x = MultiDomain.make(x)
         if (self, x) in MultiDomain._subsetCache:
             return True
@@ -109,15 +112,16 @@ class MultiDomain(frozendict):
         for key in self.keys():
             if key not in x:
                 return False
-            if self[key] != x[key]:
+            if self[key] is not x[key]:
                 return False
         MultiDomain._subsetCache.add((self, x))
         return True
 
     def unitedWith(self, x):
-        if not isinstance(x, MultiDomain):
+        if self is x:
+            return self
         x = MultiDomain.make(x)
-        if self == x:
+        if self is x:
             return self
         if not self.compatibleTo(x):
             raise ValueError("domain mismatch")