Move yields -> iter_yield_exprs.

jedi/evaluate/representation.py

@@ -319,7 +319,7 @@ class FunctionExecutionContext(context.TreeContext):
 
         if check_yields:
             types = set()
-            returns = funcdef.yields
+            returns = funcdef.iter_yield_exprs()
         else:
             returns = funcdef.iter_return_stmts()
             types = set(docstrings.infer_return_types(self.function_context))
@@ -352,7 +352,7 @@ class FunctionExecutionContext(context.TreeContext):
     def get_yield_values(self):
         for_parents = [(y, tree.search_ancestor(y, ('for_stmt', 'funcdef',
                                                     'while_stmt', 'if_stmt')))
-                       for y in self.tree_node.yields]
+                       for y in self.tree_node.iter_yield_exprs()]
 
         # Calculate if the yields are placed within the same for loop.
         yields_order = []

jedi/parser/python/tree.py

@@ -239,9 +239,6 @@ class Scope(PythonBaseNode, DocstringMixin):
     def __init__(self, children):
         super(Scope, self).__init__(children)
 
-    def iter_return_stmts(self):
-        return self._search_in_scope(ReturnStmt)
-
     def iter_funcdefs(self):
         return self._search_in_scope(Function)
 
@@ -461,13 +458,15 @@ class Function(ClassOrFunc):
     def name(self):
         return self.children[1]  # First token after `def`
 
-    @property
-    def yields(self):
+    def iter_yield_exprs(self):
         # TODO This is incorrect, yields are also possible in a statement.
-        return list(self._search_in_scope(YieldExpr))
+        return self._search_in_scope(YieldExpr)
+
+    def iter_return_stmts(self):
+        return self._search_in_scope(ReturnStmt)
 
     def is_generator(self):
-        return bool(self.yields)
+        return next(self.iter_yield_exprs(), None) is not None
 
     @property
     def annotation(self):