m@3: (cl:in-package #:amuse) 
m@3: 
m@2: ;; Some conditions we might want to be able to signal
m@2: 
m@2: (define-condition undefined-action (condition)
m@2:   ;; This condition would apply to an attempt to perform a meaningless
m@2:   ;; operation on an object. This may, initially, include things that
m@2:   ;; are a pain to implement but should really be used when it's
m@2:   ;; genuinely unclear what an operation means in the given
m@2:   ;; context. In such cases, a condition handler might be the best
m@2:   ;; approach anyway.
m@2:   ((operation :initarg :operation
m@2: 	      :reader undefined-action-operation)
m@2:    (datatype :initarg :datatype
m@2: 	     :reader undefined-action-datatype))
m@2:   (:report (lambda (condition stream)
m@2: 	     (format stream "The consequence of performing ~A on and object of type ~A is undefined"
m@2: 		     (undefined-action-operation condition)
m@2: 		     (undefined-action-datatype condition)))
m@2: 
m@2: (define-condition insufficient-information (condition)
m@2:   ;; It should be possible to construct genuinely minimal musical
m@2:   ;; structures. When the information in these is insufficient to
m@2:   ;; answer a query, this condition should be raised.
m@2:   ((operation :initarg :operation
m@2: 	      :reader insufficient-information-operation)
m@2:    (datatype :initarg :datatype
m@2: 	     :reader insufficient-information-datatype))
m@2:   (:report (lambda (condition stream)
m@2: 	     (format stream "The ~A object does not contain enough information to perform ~A"
m@2: 		     (insufficient-information-datatype condition)
m@2: 		     (insufficient-information-operation condition)))
m@2: 
m@2: