fixes #171 (closure bug)

gof/graph.py

@@ -165,7 +165,7 @@ class Value(Result):
             return self.name
         return "<" + str(self.data) + ">" #+ "::" + str(self.type)
     def clone(self):
-        return self.__class__(self.type, self.data, self.name)
+        return self.__class__(self.type, copy(self.data), self.name)
     def __set_owner(self, value):
         if value is not None:
             raise ValueError("Value instances cannot have an owner.")

gof/opt.py

@@ -33,7 +33,7 @@ class Optimizer:
     def optimize(self, env, *args, **kwargs):
         """
         This is meant as a shortcut to::
-          env.satisfy(opt)
+          opt.add_requirements(env)
           opt.apply(env)
         """
         self.add_requirements(env)

gradient.py

@@ -101,6 +101,8 @@ def grad_sources_inputs(sources, graph_inputs):
                     len(g_inputs),
                     len(node.inputs))
         for r, g_r in zip(node.inputs, g_inputs):
+            if g_r and len(sources) == 1 and sources[0][0].name and r.name:
+                g_r.name = "(d%s/d%s)" % (sources[0][0].name, r.name)
             if g_r is not None: 
                 if r in gmap:
                     gmap[r] = gmap[r] + g_r