.

wcfs/internal/xbtree.py

@@ -34,6 +34,7 @@ from __future__ import print_function, absolute_import
 from BTrees import check as bcheck
 from golang import panic
 import re
+inf = float('inf')
 
 
 # Tree represents a tree node.
@@ -41,8 +42,8 @@ class Tree:
     #   .keyv       () of keys
     #   .children   () of children  len(.children) == len(.keyv) + 1
     def __init__(t, keyv, *children):
-        assert len(children) == len(keyv) + 1, (keyv, children) # XXX empty tree
-        # XXX assert keyv ↑
+        assert len(children) == len(keyv) + 1, (keyv, children)
+        _assertIncv(keyv)
         # XXX assert children keys consistent?
         # XXX assert all children are of the same type
         t.keyv     = tuple(keyv)
@@ -69,7 +70,7 @@ class Tree:
 class Bucket:
     #   .keyv   () of keys
     def __init__(b, *keyv):     # XXX *keyv -> keyv ?
-        # XXX assert keyv ↑
+        _assertIncv(keyv)
         b.keyv = tuple(keyv)
 
     def __eq__(a, b):
@@ -136,3 +137,11 @@ def _indent(prefix, text): # -> text
     textv = [prefix+_ for _ in textv]
     text  = '\n'.join(textv)
     return text
+
+# _assertIncv asserts that values of vector v are strictly ↑
+def _assertIncv(v):
+    prev = -inf
+    for i in range(len(v)):
+        if not (v[i] > prev):
+            panic("assert incv: [%d] not ↑: %s -> %s" % (i, v[i], prev))
+        prev = v[i]