Per Abrahamsen <abraham(a)dina.kvl.dk&gt; writes: I couldn't think of any other applications than the XEmacs options file rewrite and alternative interfaces to customize, which RMS didn't think was enough to warrant an all new API. So I put the functions within the custom namespace: ;;; Properties ;; ;; User options have up to three extra values, which are manipulated ;; using functions similar to `default-value', `default-boundp' and ;; `set-default'. ;; ;; These values are: ;; ;; `standard': ;; The standard value for the user option as specified by the ;; package designer in the `defcustom' declaration. ;; `customized': ;; The value set by the user through the customize interface in ;; this session. ;; `saved': ;; The value saved by the user in any session. ;; ;; These are represented by the symbol properties `standard-value', ;; `customized-value', and `saved-value'. The value of the symbol ;; properties are nil if the symbol hasn't such a property, and a ;; cons-cell otherwise. The car of the cons-cell should be an ;; expression which, when evaluated, will yield the `standard', ;; `customized', or `saved' value. The cdr of the cons-cell is not ;; used. ;; ;; The use of a cons-cell is to make it possible to distingish `no ;; value' from a nil value. ;; ;; Evaluating the car makes it possible to have the value depend on ;; circumstances. This is particularly useful for the standard value, ;; which may depend on the setting of some other option or the ;; availability of a specific feature. (defun custom-set-standard (symbol value) "Set the standard value of SYMBOL to VALUE." (put symbol 'standard-value (cons (custom-quote value) nil))) (defun custom-standard-value (symbol) "The standard value of SYMBOL." (eval (car (get symbol 'standard-value)))) (defun custom-standard-boundp (symbol) "Non-nil if SYMBOL has a standard value." (get symbol 'standard-value)) (defun custom-set-customized (symbol value) "Set the customized value of SYMBOL to VALUE." (put symbol 'customized-value (cons (custom-quote value) nil))) (defun custom-customized-value (symbol) "The customized value of SYMBOL." (eval (car (get symbol 'customized-value)))) (defun custom-customized-boundp (symbol) "Non-nil if SYMBOL has a customized value." (get symbol 'customized-value)) (defun custom-set-saved (symbol value) "Set the saved value of SYMBOL to VALUE." (put symbol 'saved-value (cons (custom-quote value) nil))) (defun custom-saved-value (symbol) "The saved value of SYMBOL." (eval (car (get symbol 'saved-value)))) (defun custom-saved-boundp (symbol) "Non-nil if SYMBOL has a saved value." (get symbol 'saved-value))