# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1339200116 -7200
# Node ID d486a4cf17305b3bae36af13221778b8d0b478fa
# Parent  830194e3b6aba66ed25961c77c49010e9aa6e6a9
Improved contributor and usage discovery where contribution loops are encountered.
Added a test of nested conditional statements.
Updated the "to do" list.

diff -r 830194e3b6ab -r d486a4cf1730 TO_DO.txt
--- a/TO_DO.txt	Tue Jun 05 01:54:54 2012 +0200
+++ b/TO_DO.txt	Sat Jun 09 02:01:56 2012 +0200
@@ -94,8 +94,6 @@
 Self-related Usage
 ------------------
 
-Usage of self to restrict attribute usage observations and coverage.
-
 Perform attribute usage on attributes of self as names, potentially combining observations
 across methods.
 
diff -r 830194e3b6ab -r d486a4cf1730 micropython/data.py
--- a/micropython/data.py	Tue Jun 05 01:54:54 2012 +0200
+++ b/micropython/data.py	Sat Jun 09 02:01:56 2012 +0200
@@ -390,7 +390,6 @@
                 # usage with the usage recorded directly on the user.
 
                 self.get_usage_from_contributors(user)
-                self.set_contributors(user)
 
                 # Record the defining user on each contributor.
 
@@ -485,21 +484,6 @@
                 attrtypes[name] = objtypes
         return attrtypes
 
-    def set_contributors(self, node):
-        if not hasattr(node, "_attrcontributors"):
-            node._attrcontributors = None
-            all_contributors = set()
-
-            for contributor in node._attrbranches:
-                all_contributors.add(contributor)
-                self.set_contributors(contributor)
-
-                contributors = contributor._attrcontributors
-                if contributors is not None:
-                    all_contributors.update(contributors)
-
-            node._attrcontributors = all_contributors
-
     def get_usage_from_contributors(self, node):
 
         """
@@ -513,6 +497,7 @@
 
         if not hasattr(node, "_attrcombined"):
             node._attrcombined = None
+            node._attrcontributors = None
 
             for contributor in node._attrbranches:
 
@@ -522,23 +507,33 @@
 
                 # Collect unfinished contributors and affected nodes.
 
-                if node._attrcombined is None:
+                # Where the contributor is already set to None, a loop has
+                # occurred and this node will need to have its usage
+                # recalculated later for the unfinished contributor.
+
+                if contributor._attrcombined is None:
                     if not unfinished.has_key(contributor):
                         unfinished[contributor] = []
                     unfinished[contributor].append(node)
                     continue
 
+                # Where the contributor provides usage details, it may also
+                # communicate unfinished contributor information. As a
+                # consequence, this node is also affected.
+
                 for unfinished_contributor, nodes in unfinished_contributors.items():
                     if not unfinished.has_key(unfinished_contributor):
                         unfinished[unfinished_contributor] = nodes
                     else:
                         unfinished[unfinished_contributor] += nodes
 
-                unfinished[contributor].append(node)
+                    if node not in unfinished[unfinished_contributor]:
+                        unfinished[unfinished_contributor].append(node)
 
             # Set the current state of the usage on this node.
 
-            node._attrcombined = self.get_usage_from_contributors_for_node(node)
+            node._attrcombined, node._attrcontributors = \
+                self.get_usage_from_contributors_for_node(node)
 
             # Complete unfinished contributors relying on this node.
 
@@ -547,7 +542,10 @@
                 for contributor in unfinished[node]:
                     if not contributor in processed:
                         processed.add(contributor)
-                        contributor._attrcombined = self.get_usage_from_contributors_for_node(contributor)
+
+                        contributor._attrcombined, contributor._attrcontributors = \
+                            self.get_usage_from_contributors_for_node(contributor)
+
                 del unfinished[node]
 
         return unfinished
@@ -558,12 +556,18 @@
 
         contributor_usage = {}
         all_contributions = []
+        all_contributors = set()
 
         for contributor in node._attrbranches:
             usage = contributor._attrcombined
             if usage is not None:
                 all_contributions.append(usage)
 
+            all_contributors.add(contributor)
+            contributors = contributor._attrcontributors
+            if contributors is not None:
+                all_contributors.update(contributors)
+
         # Get contributed usage for each contributor.
         # This gathers usage for each name such as {(a, b), (c, d)} and
         # {(a, b), (e, f)} into a single set {(a, b), (c, d), (e, f)}.
@@ -578,7 +582,7 @@
         # Thus, usage of {(f, g)} combined with {(a, b), (c, d)} would give
         # {(f, g, a, b), (f, g, c, d)}.
 
-        return combine_mapping_dicts(deepen_mapping_dict(node._attrnames), contributor_usage)
+        return combine_mapping_dicts(deepen_mapping_dict(node._attrnames), contributor_usage), all_contributors
 
     def use_attribute(self, name, attrname, value=None):
 
diff -r 830194e3b6ab -r d486a4cf1730 tests/attribute_access_type_restriction_conditional_nested.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/attribute_access_type_restriction_conditional_nested.py	Sat Jun 09 02:01:56 2012 +0200
@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+
+class C:
+    def f(self):
+        return 1
+    def g(self):
+        return 2
+
+class D:
+    def g(self):
+        return 3
+
+def test_conditional(x, obj):
+    obj.f()
+    if x:
+        if x:
+            a = obj.g()
+        return a
+    return 1
+
+c = C()
+d = D()
+result1_2 = test_conditional(1, c)
+
+# vim: tabstop=4 expandtab shiftwidth=4