* lisp/emacs-lisp/helpers.el: Move from helpers.el. Use lexical-binding.

lisp/emacs-lisp/helpers.el

@@ -0,0 +1,42 @@
+;;; helpers.el --- Some non-essential library extensions  -*- lexical-binding:t -*-
+
+;; Copyright (C) 2013 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
+;; Keywords: convenience
+;; Package: emacs
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(defsubst hash-table-keys (hash-table)
+  "Return a list of keys in HASH-TABLE."
+  (let ((keys '()))
+    (maphash (lambda (k _v) (push k keys)) hash-table)
+    keys))
+
+(defsubst hash-table-values (hash-table)
+  "Return a list of values in HASH-TABLE."
+  (let ((values '()))
+    (maphash (lambda (_k v) (push v values)) hash-table)
+    values))
+
+(provide 'helpers)
+
+;;; helpers.el ends here