2 files changed, 16 insertions(+), 1 deletions(-)

M found/nstore.py
M found/vnstore.py

@@ 42,7 42,10 @@ def combinations(tab):
 
 
 def ok(solutions, tab):
-    """Check that SOLUTIONS of TAB is a correct solution"""
+    """Check that SOLUTIONS is a possible set of permutations of columns
+    of TAB that allow to query any pattern of TAB in hop.
+
+    """
     cx = combinations(tab)
 
     for combination in cx:


@@ 60,6 63,11 @@ def ok(solutions, tab):
 
 
 def _compute_indices(n):
+    # I do not understand the algorithm, it gives a good result
+    # according to the above function called `ok`.
+    #
+    # ref: https://stackoverflow.com/a/55148433/140837
+
     tab = list(range(n))
     cx = list(itertools.combinations(tab, n // 2))
     for c in cx:


@@ 117,6 125,7 @@ def make(name, prefix, n):
     return _NStore(name, tuple(prefix), n, list(_compute_indices(n)))
 
 
+# TODO: rename `add` to `set`
 def add(tx, nstore, *items, value=b''):
     assert len(items) == nstore.n, "invalid item count"
     for subspace, index in enumerate(nstore.indices):

@@ 56,6 56,7 @@ def make(self, subspace, n):
         nstore.open('tuples', subspace + ['tuples'], n + 1),
     )
 
+
 def change_create(tx, vnstore):
     changeid = uuid4()
     # When significance is `None` the change is skipped by


@@ 64,6 65,7 @@ def change_create(tx, vnstore):
     nstore.add(tx, vnstore.history, changeid, 'message', None)
     return changeid
 
+
 def change_message(tx, vnstore, changeid, message):
     # If there is an existing message, remove it.
     bindings = nstore.query(tx, vnstore.history, changeid, 'message', nstore.var('message'))


@@ 74,11 76,13 @@ def change_message(tx, vnstore, changeid, message):
     # Add message
     nstore.add(tx, vnstore.history, changeid, 'message', message)
 
+
 def change_apply(tx, vnstore, changeid):
     # apply change by settings a verionstamp
     nstore.remove(tx, vnstore.history, changeid, 'significance', None)
     nstore.add(tx, vnstore.history, changeid, 'significance', found.Versionstamp())
 
+
 def ask(tx, vnstore, *items):
     assert len(items) == vnstore.n, "Incorrect count of ITEMS"
     # Complexity is at least O(n), where n is the number of times the


@@ 115,6 119,7 @@ def add(vnstore, tx, change_id, *items):
     self._tuples.add(tr, *items, value=value)
     return True
 
+
 def delete(tx, vnstore, change_id, *items):
     assert len(items) == vnstore.n
     if not ask(tx, vnstore, *items):


@@ 126,6 131,7 @@ def delete(tx, vnstore, change_id, *items):
     self._tuples.add(tr, *items, value=value)
     return True
 
+
 def _from(self, tr, *pattern, seed=Map()):  # seed is immutable
     """Yields bindings that match PATTERN"""
     assert len(pattern) == len(self._items), "invalid item count"