require -> require_set, __require__ -> __env_require__

gof/env.py

@@ -53,7 +53,22 @@ class InconsistencyError(GofError):
     """
     pass
 
+def require_set(cls):
+    """Return the set of objects named in a __env_require__ field in a base class"""
+    r = set()
 
+    if hasattr(cls, '__class__'):
+        cls = cls.__class__
+
+    bases = utils.all_bases(cls, lambda cls: hasattr(cls, '__env_require__'))
+
+    for base in bases:
+        req = base.__env_require__
+        if isinstance(req, (list, tuple)):
+            r.update(req)
+        else:
+            r.add(req)
+    return r
 
 class Env(graph.Graph):
     """
@@ -179,7 +194,7 @@ class Env(graph.Graph):
         return True
 
     def satisfy(self, x):
-        for feature_class in x.require():
+        for feature_class in require_set(x):
             self.add_feature(feature_class)
 
     def add_feature(self, feature_class, do_import = True):

gof/lib.py

@@ -58,6 +58,21 @@ def compute(*nodes):
     """Recursively evaluate each node (in a quick & dirty way)."""
     compute_from(nodes, set())
 
+def root_inputs(input):
+    """Return the leaves of a search through consecutive view_map()s"""
+    owner = input.owner
+    if owner:
+        view_map = owner.view_map()
+        if input in view_map:
+            answer = []
+            for input2 in view_map[input]:
+                answer.append(root_inputs(input2))
+            return answer
+        else:
+            return [input]
+    else:
+        return [input]
+
 class ForbidConstantOverwrite(features.Listener, features.Constraint):
 
     def __init__(self, env):
@@ -346,7 +361,7 @@ class DestroyHandler(features.Listener, features.Constraint, features.Orderings)
 
 class NewPythonOp(Op):
 
-    __require__ = DestroyHandler
+    __env_require__ = DestroyHandler
 
     def view_map(self):
         return {}
@@ -517,7 +532,7 @@ class PythonOp(NewPythonOp):
             if output not in except_list:
                 output.alloc()
     
-    __require__ = ForbidConstantOverwrite
+    __env_require__ = ForbidConstantOverwrite
 
     def __copy__(self):
         """

gof/op.py

@@ -28,7 +28,6 @@ class Op(object):
     """
 
     __slots__ = ['_inputs', '_outputs']
-    __require__ = []
 
     #create inputs and outputs as read-only attributes
     inputs = property(lambda self: self._inputs, doc = "The list of this Op's input Results.")
@@ -229,11 +228,10 @@ class Op(object):
         """
         r = set()
 
-        bases = all_bases(cls, lambda cls: hasattr(cls, '__require__'))
-        bases.append(cls)
+        bases = all_bases(cls, lambda cls: hasattr(cls, '__env_require__'))
 
         for base in bases:
-            req = base.__require__
+            req = base.__env_require__
             if isinstance(req, (list, tuple)):
                 r.update(req)
             else:

gof/opt.py

@@ -9,8 +9,6 @@ import ext
 
 class Optimizer:
 
-    __require__ = ()
-    
     def apply(self, env):
         pass
 
@@ -18,27 +16,6 @@ class Optimizer:
         env.satisfy(self)
         self.apply(env)
 
-    @classmethod
-    def require(cls):
-        """
-        Returns a list of EnvFeature subclasses that must be used by
-        any Env manipulating this kind of op. For instance, a
-        Destroyer requires features.DestroyHandler to guarantee that
-        various destructive operations don't interfere.
-        """
-        r = set()
-
-        bases = utils.all_bases(cls, lambda cls: hasattr(cls, '__require__'))
-        bases.append(cls)
-
-        for base in bases:
-            req = base.__require__
-            if isinstance(req, (list, tuple)):
-                r.update(req)
-            else:
-                r.add(req)
-        return r
-
     def __call__(self, env):
         self.optimize(env)
 
@@ -88,7 +65,7 @@ class LocalOptimizer(Optimizer):
 
 class OpSpecificOptimizer(LocalOptimizer):
 
-    __require__ = features.InstanceFinder
+    __env_require__ = features.InstanceFinder
 
     opclass = Op
 
@@ -100,7 +77,7 @@ class OpSpecificOptimizer(LocalOptimizer):
 
 class OpSubOptimizer(Optimizer):
 
-    __require__ = features.InstanceFinder
+    __env_require__ = features.InstanceFinder
 
     def __init__(self, op1, op2):
         if not op1.has_default_output:
@@ -127,7 +104,7 @@ class OpSubOptimizer(Optimizer):
 
 class OpRemover(Optimizer):
 
-    __require__ = features.InstanceFinder
+    __env_require__ = features.InstanceFinder
 
     def __init__(self, opclass):
         self.opclass = opclass