hello, since our last mail working with associations turned out to go quite well but one more problem came up: i tried to change the associations by removing it and replacing it by a new association. but the function "remove-association" only works partially.
1. in this one-to-one association the function doesn't work at all. --- (defpclass job() ((title :initarg :title :accessor title-of :index t) (company :initarg :company :accessor company-of :index t) (job-holder :initarg :job-holder :accessor job-holder-of :associate person))) (defpclass person() ((name :initarg :name :accessor name-of :index t) (job :initarg :job :accessor job-of :associate job))) --- an error message shows up: (remove-association *job1* 'job-holder *person1*) ; -> There is no applicable method for the generic function #<STANDARD-GENERIC-FUNCTION ELEPHANT::OID (1)> when called with arguments (NIL). same thing happens when i use the following statement: (setf (job-holder-of *job1*) nil) 2. by one-to-many associations generally nothing happens at all. --- (defpclass job() ((title :initarg :title :accessor title-of :index t) (company :initarg :company :accessor company-of :index t) (job-holders :accessor job-holders-of :associate (person job)))) (defpclass person() ((name :initarg :name :accessor name-of :index t) (job :initarg :job :accessor job-of :associate job))) --- it only works in this case: --- (drop-instance *person2*) (remove-association *job2* 'job-holders *person2*) --- 3. in the case of many-to-many associations everything goes fine. how do i get the "remove-association" function to work? are there other ways for changing associations? thank you for your help lukas _______________________________________________ elephant-devel site list elephant-devel@common-lisp.net http://common-lisp.net/mailman/listinfo/elephant-devel
