.

wcfs/internal/xbtree.py

@@ -86,15 +86,21 @@ inf = float('inf')
 
 
 # Tree represents a tree node.
-class Tree:
+class Tree(object):
     #   .keyv       () of keys
     #   .children   () of children  len(.children) == len(.keyv) + 1
     def __init__(t, keyv, *children):
         assert len(children) == len(keyv) + 1, (keyv, children)
         _assertIncv(keyv)
-        # XXX assert all children are of the same type
-        # XXX assert type(child) is Tree | Bucket
-        # XXX assert children keys consistent
+        if len(children) > 0:
+            # assert all children are of the same type
+            childtypes = set([type(_) for _ in children])
+            if len(childtypes) != 1:
+                panic("children are of distinct types: %s" % (childtypes,))
+            # assert type(child) is Tree | Bucket
+            childtype = childtypes.pop()
+            assert childtype in (Tree, Bucket), childtype
+            # XXX assert children keys consistent
         t.keyv     = tuple(keyv)
         t.children = tuple(children)
 
@@ -120,11 +126,9 @@ class Tree:
     #    return 'R'+str(t)
 
     # TODO def graphviz() -> str for graphviz
-    # TODO def TopoEncode() -> str with topology encoding
-    # TODO @staticmethod def TopoDecode(in) <- Tree from topology string
 
 # Bucked represents a bucket node.
-class Bucket:
+class Bucket(object):
     #   .keyv   () of keys
     def __init__(b, *keyv):     # XXX *keyv -> keyv ?
         _assertIncv(keyv)