# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1203637348 -3600
# Node ID 0fef6a91098cda91110dbb050475199039b658ac
# Parent  27ab716dcedb9a6e8636544bb1c407b4a67b73d8
Attempt to provide instance attribute position re-use.
Added a test of subclasses.

diff -r 27ab716dcedb -r 0fef6a91098c micropython/inspect.py
--- a/micropython/inspect.py	Tue Feb 19 00:05:22 2008 +0100
+++ b/micropython/inspect.py	Fri Feb 22 00:42:28 2008 +0100
@@ -252,14 +252,17 @@
         self.node = node
 
         self.bases = []
-        self.instattr = set() # instance attributes
+        self.instattr = set()           # instance attributes
+        self.instattr_relocated = set() # instance attributes which do not have
+                                        # the same position as those of the same
+                                        # name in some superclasses
 
-        self.all_instattr = None # cache for instance_attributes
-        self.all_instattr_names = None # from all_instattr
-        self.all_classattr = None # cache for all_class_attributes
+        self.all_instattr = None        # cache for instance_attributes
+        self.all_instattr_names = None  # from all_instattr
+        self.all_classattr = None       # cache for all_class_attributes
         self.all_classattr_names = None # from all_classattr
-        self.allattr = None # cache for all_attributes
-        self.allattr_names = None # from allattr
+        self.allattr = None             # cache for all_attributes
+        self.allattr_names = None       # from allattr
 
         # Image generation details.
 
@@ -329,25 +332,74 @@
 
         if self.all_instattr is None:
             self.all_instattr = {}
-            instattr = set()
+            instattr = {}
 
             reversed_bases = self.bases[:]
             reversed_bases.reverse()
+
+            # For the bases in reverse order, acquire instance attribute
+            # details.
+
             for cls in reversed_bases:
-                instattr.update(cls.instance_attributes().keys())
+                for name, attr in cls.instance_attributes().items():
+                    if not instattr.has_key(name):
+                        instattr[name] = set()
+                    instattr[name].add(attr.position)
 
             # Record instance attributes provided by this class and its bases,
             # along with their positions.
 
-            instattr.update(self.instattr)
+            for name in self.instattr:
+                if not instattr.has_key(name):
+                    instattr[name] = set([-1]) # position not yet defined
+
+            if not instattr:
+                self.all_instattr = {}
+            else:
+                positions = instattr.items()
+                instarray = [None] * len(positions)
+
+                # Get the positions in ascending order of list size, with lists
+                # of the same size ordered according to their smallest position
+                # value.
+
+                positions.sort(self._cmp_positions)
+                #print self.name, positions
 
-            for i, name in enumerate(instattr):
-                self.all_instattr[name] = Attr(i, None, name)
+                # Get the names in position order.
+
+                held = []
+
+                for name, pos in positions:
+                    pos = list(pos)
+                    if pos[0] != -1 and instarray[pos[0]] is None:
+                        instarray[pos[0]] = name, Attr(pos[0], None, name)
+                    else:
+                        if pos[0] != -1 or len(pos) > 1:
+                            self.instattr_relocated.add(name)
+                        held.append((name, pos))
+
+                for i, attr in enumerate(instarray):
+                    if attr is None:
+                        name, pos = held.pop()
+                        instarray[i] = name, Attr(i, None, name)
+
+                self.all_instattr = dict(instarray)
 
             self.all_instattr_names = self.all_instattr.keys()
 
         return self.all_instattr
 
+    def _cmp_positions(self, a, b):
+        name_a, list_a = a
+        name_b, list_b = b
+        if len(list_a) < len(list_b):
+            return -1
+        elif len(list_a) > len(list_b):
+            return 1
+        else:
+            return cmp(min(list_a), min(list_b))
+
     def all_attribute_names(self):
 
         """
diff -r 27ab716dcedb -r 0fef6a91098c tests/subclass.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tests/subclass.py	Fri Feb 22 00:42:28 2008 +0100
@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+
+class A:
+    def __init__(self, x):
+        self.x = x
+
+    def a(self):
+        pass
+
+class B(A):
+    def b(self):
+        pass
+
+class C(A, B):
+    def __init__(self, x, y):
+        self.x = x
+        self.y = y
+
+    def a(self):
+        pass
+
+class D:
+    def __init__(self, y):
+        self.y = y
+
+class E(C, D):
+    pass
+
+class F(A, D):
+    pass
+
+# vim: tabstop=4 expandtab shiftwidth=4