Move YES to astroid.util.

YES is needed by other components of astroid, components which aren't
necessarily related to astroid.bases. In order to reduce circular
interdependencies between components, YES is moved into a new module,
tailored for various *utilities*.

1 files changed, 15 insertions, 14 deletions

diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index e428f03f..348278ab 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -36,6 +36,7 @@ from astroid import manager
 from astroid import mixins
 from astroid import node_classes
 from astroid import decorators as decorators_mod
+from astroid import util
 
 
 BUILTINS = six.moves.builtins.__name__
@@ -537,7 +538,7 @@ class DictComp(ComprehensionScope):
         self.generators = []
 
     def bool_value(self):
-        return bases.YES
+        return util.YES
 
 
 class SetComp(ComprehensionScope):
@@ -549,7 +550,7 @@ class SetComp(ComprehensionScope):
         self.generators = []
 
     def bool_value(self):
-        return bases.YES
+        return util.YES
 
 
 class _ListComp(bases.NodeNG):
@@ -559,7 +560,7 @@ class _ListComp(bases.NodeNG):
     generators = None
 
     def bool_value(self):
-        return bases.YES
+        return util.YES
 
 
 if six.PY3:
@@ -885,7 +886,7 @@ class Function(bases.Statement, Lambda):
                 c.hide = True
                 c.parent = self
                 class_bases = [next(b.infer(context)) for b in caller.args[1:]]
-                c.bases = [base for base in class_bases if base != bases.YES]
+                c.bases = [base for base in class_bases if base != util.YES]
                 c._metaclass = metaclass
                 yield c
                 return
@@ -898,7 +899,7 @@ class Function(bases.Statement, Lambda):
                     for infered in returnnode.value.infer(context):
                         yield infered
                 except exceptions.InferenceError:
-                    yield bases.YES
+                    yield util.YES
 
     def bool_value(self):
         return True
@@ -935,7 +936,7 @@ def _is_metaclass(klass, seen=None):
                 if isinstance(baseobj, bases.Instance):
                     # not abstract
                     return False
-                if baseobj is bases.YES:
+                if baseobj is util.YES:
                     continue
                 if baseobj is klass:
                     continue
@@ -1089,7 +1090,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
                 isinstance(name_node.value, six.string_types)):
             name = name_node.value
         else:
-            return bases.YES
+            return util.YES
 
         result = Class(name, None)
 
@@ -1101,7 +1102,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
             # There is currently no AST node that can represent an 'unknown'
             # node (YES is not an AST node), therefore we simply return YES here
             # although we know at least the name of the class.
-            return bases.YES
+            return util.YES
 
         # Get the members of the class
         try:
@@ -1368,13 +1369,13 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
                     except exceptions.NotFoundError:
                         yield infered
                     else:
-                        yield bases.YES
+                        yield util.YES
                 else:
                     yield function_to_method(infered, self)
         except exceptions.NotFoundError:
             if not name.startswith('__') and self.has_dynamic_getattr(context):
                 # class handle some dynamic attributes, return a YES object
-                yield bases.YES
+                yield util.YES
             else:
                 raise exceptions.InferenceError(name)
 
@@ -1455,7 +1456,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
             # Expects this from Py3k TreeRebuilder
             try:
                 return next(node for node in self._metaclass.infer()
-                            if node is not bases.YES)
+                            if node is not util.YES)
             except (exceptions.InferenceError, StopIteration):
                 return None
         if six.PY3:
@@ -1478,7 +1479,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
             infered = next(assignment.infer())
         except exceptions.InferenceError:
             return
-        if infered is bases.YES: # don't expose this
+        if infered is util.YES: # don't expose this
             return None
         return infered
 
@@ -1529,7 +1530,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
                 values = [item[0] for item in slots.items]
             else:
                 values = slots.itered()
-            if values is bases.YES:
+            if values is util.YES:
                 continue
             if not values:
                 # Stop the iteration, because the class
@@ -1539,7 +1540,7 @@ class Class(bases.Statement, LocalsDictNodeNG, mixins.FilterStmtsMixin):
             for elt in values:
                 try:
                     for infered in elt.infer():
-                        if infered is bases.YES:
+                        if infered is util.YES:
                             continue
                         if (not isinstance(infered, node_classes.Const) or
                                 not isinstance(infered.value,