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, 41 insertions, 40 deletions

diff --git a/astroid/inference.py b/astroid/inference.py
index f05b163..ae8a5d2 100644
--- a/astroid/inference.py
+++ b/astroid/inference.py
@@ -25,6 +25,7 @@ import operator
 from astroid import helpers
 from astroid import nodes
 from astroid import protocols
+from astroid import util
 from astroid.manager import AstroidManager
 from astroid.exceptions import (
     AstroidError, InferenceError, NoDefault,
@@ -32,7 +33,7 @@ from astroid.exceptions import (
     UnaryOperationError,
     BinaryOperationError,
 )
-from astroid.bases import (YES, Instance, InferenceContext, BoundMethod,
+from astroid.bases import (Instance, InferenceContext, BoundMethod,
                            _infer_stmts, copy_context, path_wrapper,
                            raise_if_nothing_infered, yes_if_nothing_infered)
 
@@ -88,13 +89,13 @@ class CallContext(object):
                 if self.starargs is not None:
                     its = []
                     for infered in self.starargs.infer(context):
-                        if infered is YES:
-                            its.append((YES,))
+                        if infered is util.YES:
+                            its.append((util.YES,))
                             continue
                         try:
                             its.append(infered.getitem(argindex, context).infer(context))
                         except (InferenceError, AttributeError):
-                            its.append((YES,))
+                            its.append((util.YES,))
                         except (IndexError, TypeError):
                             continue
                     if its:
@@ -103,13 +104,13 @@ class CallContext(object):
         if self.kwargs is not None:
             its = []
             for infered in self.kwargs.infer(context=context):
-                if infered is YES:
-                    its.append((YES,))
+                if infered is util.YES:
+                    its.append((util.YES,))
                     continue
                 try:
                     its.append(infered.getitem(name, context).infer(context=context))
                 except (InferenceError, AttributeError):
-                    its.append((YES,))
+                    its.append((util.YES,))
                 except (IndexError, TypeError):
                     continue
             if its:
@@ -190,7 +191,7 @@ def infer_callfunc(self, context=None):
                                           kwargs=self.kwargs)
     callcontext.boundnode = None
     for callee in self.func.infer(context):
-        if callee is YES:
+        if callee is util.YES:
             yield callee
             continue
         try:
@@ -241,7 +242,7 @@ nodes.From._infer = path_wrapper(infer_from)
 def infer_getattr(self, context=None):
     """infer a Getattr node by using getattr on the associated object"""
     for owner in self.expr.infer(context):
-        if owner is YES:
+        if owner is util.YES:
             yield owner
             continue
         try:
@@ -271,13 +272,13 @@ nodes.Global._infer = path_wrapper(infer_global)
 def infer_subscript(self, context=None):
     """infer simple subscription such as [1,2,3][0] or (1,2,3)[-1]"""
     value = next(self.value.infer(context))
-    if value is YES:
-        yield YES
+    if value is util.YES:
+        yield util.YES
         return
 
     index = next(self.slice.infer(context))
-    if index is YES:
-        yield YES
+    if index is util.YES:
+        yield util.YES
         return
 
     if isinstance(index, nodes.Const):
@@ -286,13 +287,13 @@ def infer_subscript(self, context=None):
         except AttributeError:
             raise InferenceError()
         except (IndexError, TypeError):
-            yield YES
+            yield util.YES
             return
 
         # Prevent inferring if the infered subscript
         # is the same as the original subscripted object.
-        if self is assigned or assigned is YES:
-            yield YES
+        if self is assigned or assigned is util.YES:
+            yield util.YES
             return
         for infered in assigned.infer(context):
             yield infered
@@ -320,19 +321,19 @@ def _infer_boolop(self, context=None):
     try:
         values = [value.infer(context=context) for value in values]
     except InferenceError:
-        yield YES
+        yield util.YES
         return
 
     for pair in itertools.product(*values):
-        if any(item is YES for item in pair):
+        if any(item is util.YES for item in pair):
             # Can't infer the final result, just yield YES.
-            yield YES
+            yield util.YES
             continue
 
         bool_values = [item.bool_value() for item in pair]
-        if any(item is YES for item in bool_values):
+        if any(item is util.YES for item in bool_values):
             # Can't infer the final result, just yield YES.
-            yield YES
+            yield util.YES
             continue
 
         # Since the boolean operations are short circuited operations,
@@ -344,7 +345,7 @@ def _infer_boolop(self, context=None):
         #   0 and 1 -> 0
         #   1 or 0 -> 1
         #   0 or 1 -> 1
-        value = YES
+        value = util.YES
         for value, bool_value in zip(pair, bool_values):
             if predicate(bool_value):
                 yield value
@@ -363,7 +364,7 @@ def _filter_operation_errors(self, infer_callable, context, error):
             # For the sake of .infer(), we don't care about operation
             # errors, which is the job of pylint. So return something
             # which shows that we can't infer the result.
-            yield YES
+            yield util.YES
         else:
             yield result
 
@@ -383,10 +384,10 @@ def _infer_unaryop(self, context=None):
                 # value and negate its result, unless it is
                 # YES, which will be returned as is.
                 bool_value = operand.bool_value()
-                if bool_value is not YES:
+                if bool_value is not util.YES:
                     yield nodes.const_factory(not bool_value)
                 else:
-                    yield YES
+                    yield util.YES
             else:
                 if not isinstance(operand, Instance):
                     # The operation was used on something which
@@ -408,7 +409,7 @@ def _infer_unaryop(self, context=None):
                     # The unary operation special method was not found.
                     yield UnaryOperationError(operand, self.op, exc)
                 except InferenceError:
-                    yield YES
+                    yield util.YES
 
 
 @path_wrapper
@@ -561,11 +562,11 @@ def _infer_binary_operation(left, right, op, context, flow_factory):
         except NotFoundError:
             continue
         except InferenceError:
-            yield YES
+            yield util.YES
             return
         else:
-            if any(result is YES for result in results):
-                yield YES
+            if any(result is util.YES for result in results):
+                yield util.YES
                 return
 
             # TODO(cpopa): since the inferrence engine might return
@@ -577,7 +578,7 @@ def _infer_binary_operation(left, right, op, context, flow_factory):
                                   if _is_not_implemented(result))
             if not_implemented and not_implemented != len(results):
                 # Can't decide yet what this is, not yet though.
-                yield YES
+                yield util.YES
                 return
 
             for result in results:
@@ -597,9 +598,9 @@ def _infer_binop(self, context):
     op = self.op
 
     for lhs in left.infer(context=context):
-        if lhs is YES:
+        if lhs is util.YES:
             # Don't know how to process this.
-            yield YES
+            yield util.YES
             return
 
         # TODO(cpopa): if we have A() * A(), trying to infer
@@ -609,9 +610,9 @@ def _infer_binop(self, context):
         rhs_context = context.clone()
         rhs_context.path = set()
         for rhs in right.infer(context=rhs_context):
-            if rhs is YES:
+            if rhs is util.YES:
                 # Don't know how to process this.
-                yield YES
+                yield util.YES
                 return
 
             results = _infer_binary_operation(lhs, rhs, op,
@@ -636,9 +637,9 @@ def _infer_augassign(self, context=None):
     op = self.op
 
     for lhs in self.target.infer_lhs(context=context):
-        if lhs is YES:
+        if lhs is util.YES:
             # Don't know how to process this.
-            yield YES
+            yield util.YES
             return
 
         # TODO(cpopa): if we have A() * A(), trying to infer
@@ -648,9 +649,9 @@ def _infer_augassign(self, context=None):
         rhs_context = context.clone()
         rhs_context.path = set()
         for rhs in self.value.infer(context=rhs_context):
-            if rhs is YES:
+            if rhs is util.YES:
                 # Don't know how to process this.
-                yield YES
+                yield util.YES
                 return
 
             results = _infer_binary_operation(lhs, rhs, op,
@@ -696,14 +697,14 @@ nodes.AssAttr._infer = path_wrapper(infer_ass)
 
 def infer_empty_node(self, context=None):
     if not self.has_underlying_object():
-        yield YES
+        yield util.YES
     else:
         try:
             for infered in MANAGER.infer_ast_from_something(self.object,
                                                             context=context):
                 yield infered
         except AstroidError:
-            yield YES
+            yield util.YES
 nodes.EmptyNode._infer = path_wrapper(infer_empty_node)