+
+(defvar mel-encoding-module-alist nil)
+
+(defsubst mel-find-function-from-obarray (ob-array encoding)
+ (let* ((f (intern-soft encoding ob-array)))
+ (or f
+ (let ((rest (cdr (assoc encoding mel-encoding-module-alist))))
+ (while (and rest
+ (progn
+ (require (car rest))
+ (null (setq f (intern-soft encoding ob-array)))
+ ))
+ (setq rest (cdr rest))
+ )
+ f))))
+
+(defsubst mel-copy-method (service src-backend dst-backend)
+ (let* ((oa (symbol-value (intern (format "%s-obarray" service))))
+ (f (mel-find-function-from-obarray oa src-backend))
+ sym)
+ (when f
+ (setq sym (intern dst-backend oa))
+ (or (fboundp sym)
+ (fset sym (symbol-function f))
+ ))))
+
+(defsubst mel-copy-backend (src-backend dst-backend)
+ (let ((services mel-service-list))
+ (while services
+ (mel-copy-method (car services) src-backend dst-backend)
+ (setq services (cdr services)))))
+
+(defmacro mel-define-backend (type &optional parents)
+ "Define TYPE as a mel-backend.
+If PARENTS is specified, TYPE inherits PARENTS.
+Each parent must be backend name (string)."
+ (cons 'progn
+ (mapcar (lambda (parent)
+ `(mel-copy-backend ,parent ,type)
+ )
+ parents)))
+