Merge pull request #87 from CyberShadow/emacs-24-plus

Drop support for Emacs < 24.3

README.md

@@ -8,7 +8,7 @@
 
 An Emacs major mode for editing D code.
 
-This mode is currently known to work with Emacs 24 and 25, and believed to work with Emacs 23.
+This mode is currently known to work with Emacs 24 and 25.
 
 The best way of installing this major mode, at least for Emacs 24, is to use the packaging system. Add MELPA
 or MELPA Stable to the list of repositories to access this mode. For those who want only formal, tagged

d-mode.el

@@ -7,8 +7,9 @@
 ;; Maintainer:  Russel Winder <russel@winder.org.uk>
 ;;              Vladimir Panteleev <vladimir@thecybershadow.net>
 ;; Created:  March 2007
-;; Version:  201802141931
+;; Version:  201804041719
 ;; Keywords:  D programming language emacs cc-mode
+;; Package-Requires: ((emacs "24.3"))
 
 ;;;; NB Version number is date and time yyyymmddhhMM UTC.
 ;;;; A hook to update it automatically on save is available here:
@@ -77,11 +78,13 @@
 ;;   "Symbol's value as variable is void: compilation-error-regexp-alist-alist" errors
 (require 'compile)
 
+;; Work around Emacs (cc-mode) bug #18845
+(eval-when-compile
+  (when (and (= emacs-major-version 24) (>= emacs-minor-version 4))
+    (require 'cl)))
+
 ;; The set-difference function is used from the Common Lisp extensions.
-;; Note that this line produces a compilation warning in Emacs 24 and newer,
-;; however the replacement (cl-seq.el for our use case) was introduced
-;; in the same major version.
-(require 'cl)
+(require 'cl-lib)
 
 ;; Used to specify regular expressions in a sane way.
 (require 'rx)
@@ -171,8 +174,8 @@ operators."
 
 (c-lang-defconst c-block-prefix-disallowed-chars
   ;; Allow ':' for inherit list starters.
-  d (set-difference (c-lang-const c-block-prefix-disallowed-chars)
-                    '(?:)))
+  d (cl-set-difference (c-lang-const c-block-prefix-disallowed-chars)
+		       '(?:)))
 
 (defconst doxygen-font-lock-doc-comments
   (let ((symbol "[a-zA-Z0-9_]+")
@@ -715,12 +718,8 @@ The expression is added to `compilation-error-regexp-alist' and
   :type 'hook
   :group 'c)
 
-;; For compatibility with Emacs < 24
-(defalias 'd-parent-mode
-  (if (fboundp 'prog-mode) 'prog-mode 'fundamental-mode))
-
 ;;;###autoload
-(define-derived-mode d-mode d-parent-mode "D"
+(define-derived-mode d-mode prog-mode "D"
   "Major mode for editing code written in the D Programming Language.
 
 See http://dlang.org for more information about the D language.