-(in-package :lisp-on-lines)
-
-(define-description description ())
-
-(defun find-description (name)
- (slot-value (find-description-class name) 'instance))
-
-(defun description-attributes (description)
- (closer-mop:class-slots (find-description-class description)))
-
-(define-layered-function attributes (description))
-
-(define-layered-method attributes (description)
- (description-attributes description))
-
-;;;!-- TODO: This is a prime candidate for optimization
-(defun find-attribute (description attribute-name)
- (find attribute-name (description-attributes description) :key #'attribute-name))
-
-(define-display ((description description))
- (format *display* "~{~A~%~}"
- (mapcar
- (lambda (attribute)
- (with-output-to-string (*display*)
- (display-attribute attribute)))
- (attributes description))))
-
-
-(define-layered-method description-of (object)
- (find-description 't))
-
-(define-layered-method description-of ((symbol symbol))
- (find-description 'symbol))
-
-(define-description symbol ()
- ((identity :label "Symbol:")
- (name
- :function #'symbol-name
- :label "Name:")
- (value
- :label "Value:"
- :function
- (lambda (symbol)
- (if (boundp symbol)
- (symbol-value symbol)
- "<UNBOUND>")))
- (package :function #'symbol-package
- :label "Package:")
- (function :label "Function:"
- :function
- (lambda (symbol)
- (if (fboundp symbol)
- (symbol-function symbol)
- "<UNBOUND>")))))
-
-
-
-
-
-
-
-
-
-
-
+(in-package :lisp-on-lines)
+
+(defvar *object* nil)
+(defvar *description*)
+
+(define-layered-function description-of (thing)
+ (:method (thing)
+ (find-description 't)))
+
+(defun description-print-name (description)
+ (description-class-name (class-of description)))
+
+(defun description-attributes (description)
+ (description-class-attributes (class-of description)))
+
+(defun description-current-attributes (description)
+ (remove-if-not
+ (lambda (attribute)
+ (and
+ (some #'layer-active-p
+ (mapcar #'find-layer
+ (slot-definition-layers
+ (attribute-effective-attribute-definition attribute))))))
+ (description-attributes description)))
+
+(defun description-active-attributes (description)
+ (remove-if-not
+ #'attribute-active-p
+ (description-attributes description)))
+
+(defun find-attribute (description attribute-name &optional (errorp t))
+ (or (find attribute-name (description-attributes description)
+ :key #'attribute-name)
+ (when errorp (error "No attribute named ~A found in ~A describing ~A" attribute-name description (described-object description)))))
+
+(define-layered-function description-active-descriptions (description)
+ (:method ((description standard-description-object))
+ (attribute-value (find-attribute description 'active-descriptions)))
+ (:method ((description attribute))
+ (attribute-active-descriptions description)))
+
+(define-layered-function description-inactive-descriptions (description)
+ (:method ((description standard-description-object))
+ (attribute-value (find-attribute description 'inactive-descriptions)))
+ (:method ((description attribute))
+ (attribute-inactive-descriptions description)))
+
+(define-layered-function attributes (description)
+ (:method (description)
+ (let* ((active-attributes
+ (find-attribute description 'active-attributes))
+ (attributes (when active-attributes
+ (ignore-errors (attribute-value active-attributes)))))
+ (remove-if-not
+ (lambda (attribute)
+ (and attribute
+ (attribute-active-p attribute)
+ (some #'layer-active-p
+ (mapcar #'find-layer
+ (slot-definition-layers
+ (attribute-effective-attribute-definition attribute))))))
+ (if attributes
+ (mapcar (lambda (spec)
+ (find-attribute
+ description
+ (if (listp spec)
+ (car spec)
+ spec)))
+ attributes)
+ (description-attributes description))))))
+
+
+(defun funcall-with-described-object (function object description &rest args)
+ (setf description (or description (description-of object)))
+ (let ((*description* description)
+ (*object* object))
+ (dletf (((described-object *description*) object))
+ (funcall-with-layer-context
+ (modify-layer-context
+ (if (standard-description-p *description*)
+ (adjoin-layer *description* (current-layer-context))
+ (current-layer-context))
+ :activate (description-active-descriptions *description*)
+ :deactivate (description-inactive-descriptions *description*))
+ (lambda () (contextl::funcall-with-special-initargs
+ (loop
+ :for (key val) :on args :by #'cddr
+ :collect (list (find key (description-attributes *description*)
+ :key #'attribute-keyword)
+ :value val))
+ (lambda ()
+ (contextl::funcall-with-special-initargs
+ (let ((attribute (ignore-errors (find-attribute *description* 'active-attributes))))
+ (when attribute
+ (loop for spec in (attribute-value attribute)
+ if (listp spec)
+ collect (cons (or
+ (find-attribute *description* (car spec))
+ (error "No attribute matching ~A" (car spec)))
+ (cdr spec)))))
+ function))))))))
+
+
+
+
+(defmacro define-description (name &optional superdescriptions &body options)
+ (let ((description-name (defining-description name)))
+ (destructuring-bind (&optional slots &rest options) options
+ (let ((description-layers (cdr (assoc :in-description options))))
+ (if description-layers
+ `(progn ;eval-when (:compile-toplevel :load-toplevel :execute)
+ ,@(loop
+ :for layer
+ :in description-layers
+ :collect `(define-description
+ ,name ,superdescriptions ,slots
+ ,@(acons
+ :in-layer (defining-description layer)
+ (remove :in-description options :key #'car)))))
+ `(progn ;eval-when (:compile-toplevel :load-toplevel :execute)
+ ; `(progn
+ (defclass ,description-name
+ ,(append (mapcar #'defining-description
+ superdescriptions)
+ (unless (or (eq t name)
+ (assoc :mixinp options))
+ (list (defining-description t))))
+ ,(if slots slots '())
+ ,@options
+ ,@(unless (assoc :metaclass options)
+ '((:metaclass standard-description-class))))
+ (initialize-descriptions)
+ (find-description ',name)))))))
+
+
+
+
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+