* New built-in function `builtins.attrNames' that returns the

names of the attributes in an attribute set.

tests/lang/eval-okay-attrnames.exp

@@ -0,0 +1 @@
+Str("newxfoonewxy",[])

tests/lang/eval-okay-attrnames.nix

@@ -0,0 +1,11 @@
+with import ./lib.nix;
+
+let
+
+  attrs = {y = "y"; x = "x"; foo = "foo";} // rec {x = "newx"; bar = x;};
+
+  names = builtins.attrNames attrs;
+
+  values = map (name: builtins.getAttr name attrs) names;
+
+in concat values