I need to define an inheritance behavior that concatenates string-values
of superclass-initforms with local slot initforms. E.g.

(defclass super()     ((f :accessor f :initform "head")) (:metaclass
user-class))
(defclass sub(super)  ((f :accessor f :initform "tail")) (:metaclass
user-class))

I'd like to get the following:

(f(make-instance'sub)) -> "head tail"


I didn't find a standard option in defclass slot-descriptions for this.
I'd like to define the concatenate combination for each meta-class
'user-class'.

Any idea? Thanks in advance!

Yours, Marc Dzaebel