Merged revisions 67954 via svnmerge from

benjamin.peterson · benjamin.peterson · commit 9c688a93ffe0 · 2008-12-27T19:03:36.000Z
svn+ssh://pythondev@svn.python.org/python/trunk ........ r67954 | benjamin.peterson | 2008-12-27 12:24:11 -0600 (Sat, 27 Dec 2008) | 1 line #4748 lambda generators shouldn't return values ........ git-svn-id: http://svn.python.org/projects/python/branches/py3k@67959 6015fed2-1504-0410-9fe1-9d1591cc4771
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
@@ -928,6 +928,16 @@
 'f'
 >>> repr(g)  # doctest: +ELLIPSIS
 '<generator object f at ...>'
+
+Lambdas shouldn't have their usual return behavior.
+
+>>> x = lambda: (yield 1)
+>>> list(x())
+[1]
+
+>>> x = lambda: ((yield 1), (yield 2))
+>>> list(x())
+[1, 2]
 """
 
 # conjoin is a simple backtracking generator, named in honor of Icon's
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -56,6 +56,8 @@ Core and Builtins
 - Issue #4569: Interpreter crash when mutating a memoryview with an item size
   larger than 1.
 
+- Issue #4748: Lambda generators no longer return a value.
+
 Library
 -------
 
diff --git a/Python/compile.c b/Python/compile.c
@@ -1704,7 +1704,12 @@ compiler_lambda(struct compiler *c, expr_ty e)
 	c->u->u_argcount = asdl_seq_LEN(args->args);
 	c->u->u_kwonlyargcount = asdl_seq_LEN(args->kwonlyargs);
 	VISIT_IN_SCOPE(c, expr, e->v.Lambda.body);
-	ADDOP_IN_SCOPE(c, RETURN_VALUE);
+	if (c->u->u_ste->ste_generator) {
+		ADDOP_IN_SCOPE(c, POP_TOP);
+	}
+	else {
+		ADDOP_IN_SCOPE(c, RETURN_VALUE);
+	}
 	co = assemble(c, 1);
 	compiler_exit_scope(c);
 	if (co == NULL)
