;;; luna.el --- tiny OOP system kernel
-;; Copyright (C) 1999 Electrotechnical Laboratory, JAPAN.
+;; Copyright (C) 1999,2000 Free Software Foundation, Inc.
;; Author: MORIOKA Tomohiko <tomo@m17n.org>
;; Keywords: OOP
(eval-when-compile (require 'cl))
+
+;;; @ class
+;;;
+
(defmacro luna-find-class (name)
- "Return the luna-class of the given NAME."
+ "Return a luna-class that has NAME."
`(get ,name 'luna-class))
+;; Give NAME (symbol) the luna-class CLASS.
(defmacro luna-set-class (name class)
`(put ,name 'luna-class ,class))
+;; Return the obarray of luna-class CLASS.
(defmacro luna-class-obarray (class)
`(aref ,class 1))
+;; Return the parents of luna-class CLASS.
(defmacro luna-class-parents (class)
`(aref ,class 2))
+;; Return the number of slots of luna-class CLASS.
(defmacro luna-class-number-of-slots (class)
`(aref ,class 3))
-(defmacro luna-define-class (type &optional parents slots)
- "Define TYPE as a luna-class.
-If PARENTS is specified, TYPE inherits PARENTS.
-Each parent must be name of luna-class (symbol).
-If SLOTS is specified, TYPE will be defined to have them."
- `(luna-define-class-function ',type ',parents ',slots))
+(defmacro luna-define-class (class &optional parents slots)
+ "Define CLASS as a luna-class.
+CLASS always inherits the luna-class `standard-object'.
+
+The optional 1st arg PARENTS is a list luna-class names. These
+luna-classes are also inheritted by CLASS.
+
+The optional 2nd arg SLOTS is a list of slots CLASS will have."
+ `(luna-define-class-function ',class ',(append parents '(standard-object))
+ ',slots))
+
-(defun luna-define-class-function (type &optional parents slots)
+;; Define CLASS as a luna-class. PARENTS, if non-nil, is a list of
+;; luna-class names inherited by CLASS. SLOTS, if non-nil, is a list
+;; of slots belonging to CLASS.
+
+(defun luna-define-class-function (class &optional parents slots)
(let ((oa (make-vector 31 0))
(rest parents)
parent name
(setq name (symbol-name sym))
(unless (intern-soft name oa)
(put (intern name oa) 'luna-slot-index (+ j b))
- (setq i (1+ i))
- )))
- (luna-class-obarray (luna-find-class parent)))
- )
+ (setq i (1+ i)))))
+ (luna-class-obarray (luna-find-class parent))))
(setq rest slots)
(while rest
(setq name (symbol-name (pop rest)))
(unless (intern-soft name oa)
(put (intern name oa) 'luna-slot-index i)
- (setq i (1+ i))
- ))
- (luna-set-class type (vector 'class oa parents i))
- ))
+ (setq i (1+ i))))
+ (luna-set-class class (vector 'class oa parents i))))
+
+
+;; Return a member (slot or method) of CLASS that has name
+;; MEMBER-NAME.
(defun luna-class-find-member (class member-name)
(or (stringp member-name)
member-name)))))
ret)))
+
+;; Return a member (slot or method) of CLASS that has name
+;; MEMBER-NAME. If CLASS doesnt' have such a member, make it in
+;; CLASS.
+
(defsubst luna-class-find-or-make-member (class member-name)
(or (stringp member-name)
(setq member-name (symbol-name member-name)))
(intern member-name (luna-class-obarray class)))
+
+;; Return the index number of SLOT-NAME in CLASS.
+
(defmacro luna-class-slot-index (class slot-name)
`(get (luna-class-find-member ,class ,slot-name) 'luna-slot-index))
-(defmacro luna-slot-index (entity slot-name)
- `(luna-class-slot-index (luna-find-class (luna-class-name ,entity))
- ,slot-name))
+(defmacro luna-define-method (name &rest definition)
+ "Define NAME as a method of a luna class.
-(defsubst luna-slot-value (entity slot)
- "Return the value of SLOT of ENTITY."
- (aref entity (luna-slot-index entity slot)))
+Usage of this macro follows:
-(defsubst luna-set-slot-value (entity slot value)
- "Store VALUE into SLOT of ENTITY."
- (aset entity (luna-slot-index entity slot) value))
+ (luna-define-method NAME [METHOD-QUALIFIER] ARGLIST [DOCSTRING] BODY...)
-(defmacro luna-define-method (name args &rest body)
- "Define NAME as a method function of (nth 1 (car ARGS)) backend.
+The optional 1st argument METHOD-QUALIFIER specifies when and how the
+method is called.
-ARGS is like an argument list of lambda, but (car ARGS) must be
-specialized parameter. (car (car ARGS)) is name of variable and (nth
-1 (car ARGS)) is name of backend."
- (let* ((specializer (car args))
- (class (nth 1 specializer))
- (self (car specializer)))
+If it is :before, call the method before calling the parents' methods.
+
+If it is :after, call the method after calling the parents' methods.
+
+If it is :around, call the method only. The parents' methods can be
+executed by calling the function `luna-call-next-method' in BODY.
+
+Otherwize, call the method only, and the parents' methods are never
+executed. In this case, METHOD-QUALIFIER is treated as ARGLIST.
+
+ARGLIST has the form ((VAR CLASS) METHOD-ARG ...), where VAR is a
+variable name that should be bound to an entity that receives the
+message NAME, CLASS is a class name. The first argument to the method
+is VAR, and the remaining arguments are METHOD-ARGs.
+
+If VAR is nil, arguments to the method are METHOD-ARGs. This kind of
+methods can't be called from generic-function (see
+`luna-define-generic').
+
+The optional 4th argument DOCSTRING is the documentation of the
+method. If it is not string, it is treated as BODY.
+
+The optional 5th BODY is the body of the method."
+ (let ((method-qualifier (pop definition))
+ args specializer class self)
+ (if (memq method-qualifier '(:before :after :around))
+ (setq args (pop definition))
+ (setq args method-qualifier
+ method-qualifier nil))
+ (setq specializer (car args)
+ class (nth 1 specializer)
+ self (car specializer))
`(let ((func (lambda ,(if self
(cons self (cdr args))
(cdr args))
- ,@body)))
- (fset (luna-class-find-or-make-member (luna-find-class ',class) ',name)
- func))))
+ ,@definition))
+ (sym (luna-class-find-or-make-member
+ (luna-find-class ',class) ',name))
+ (cache (get ',name 'luna-method-cache)))
+ (if cache
+ (unintern ',class cache))
+ (fset sym func)
+ (put sym 'luna-method-qualifier ,method-qualifier))))
(put 'luna-define-method 'lisp-indent-function 'defun)
-(defun luna-class-find-function (class service)
- (let ((sym (luna-class-find-member class service)))
- (if (fboundp sym)
- (symbol-function sym)
- (let ((parents (luna-class-parents class))
- ret)
- (while (and parents
- (null
- (setq ret (luna-class-find-function
- (luna-find-class (pop parents))
- service)))))
- ret))))
+(def-edebug-spec luna-define-method
+ (&define name [&optional &or ":before" ":after" ":around"]
+ ((arg symbolp)
+ [&rest arg]
+ [&optional ["&optional" arg &rest arg]]
+ &optional ["&rest" arg])
+ def-body))
-(defmacro luna-find-function (entity service)
- `(luna-class-find-function (luna-find-class (luna-class-name ,entity))
- ,service))
-(defsubst luna-send (entity message &rest args)
- "Send MESSAGE to ENTITY with ARGS, and return the result."
- (apply (luna-find-function entity message)
- args))
+;; Return a list of method functions named SERVICE registered in the
+;; parents of CLASS.
+
+(defun luna-class-find-parents-functions (class service)
+ (let ((parents (luna-class-parents class))
+ ret)
+ (while (and parents
+ (null
+ (setq ret (luna-class-find-functions
+ (luna-find-class (pop parents))
+ service)))))
+ ret))
+
+;; Return a list of method functions named SERVICE registered in CLASS
+;; and the parents..
+
+(defun luna-class-find-functions (class service)
+ (let ((sym (luna-class-find-member class service)))
+ (if (fboundp sym)
+ (cond ((eq (get sym 'luna-method-qualifier) :before)
+ (cons (symbol-function sym)
+ (luna-class-find-parents-functions class service)))
+ ((eq (get sym 'luna-method-qualifier) :after)
+ (nconc (luna-class-find-parents-functions class service)
+ (list (symbol-function sym))))
+ ((eq (get sym 'luna-method-qualifier) :around)
+ (cons sym (luna-class-find-parents-functions class service)))
+ (t
+ (list (symbol-function sym))))
+ (luna-class-find-parents-functions class service))))
+
+
+;;; @ instance (entity)
+;;;
(defmacro luna-class-name (entity)
"Return class-name of the ENTITY."
(defmacro luna-set-obarray (entity obarray)
`(aset ,entity 1 ,obarray))
-(defun luna-make-entity (type &rest init-args)
- "Make instance of luna-class TYPE and return it.
-If INIT-ARGS is specified, it is used as initial values of the slots.
-It must be plist and each slot name must have prefix `:'."
- (let* ((c (get type 'luna-class))
- (v (make-vector (luna-class-number-of-slots c) nil))
- (oa (luna-class-obarray c))
- s i)
- (luna-set-class-name v type)
+(defmacro luna-slot-index (entity slot-name)
+ `(luna-class-slot-index (luna-find-class (luna-class-name ,entity))
+ ,slot-name))
+
+(defsubst luna-slot-value (entity slot)
+ "Return the value of SLOT of ENTITY."
+ (aref entity (luna-slot-index entity slot)))
+
+(defsubst luna-set-slot-value (entity slot value)
+ "Store VALUE into SLOT of ENTITY."
+ (aset entity (luna-slot-index entity slot) value))
+
+(defmacro luna-find-functions (entity service)
+ `(luna-class-find-functions (luna-find-class (luna-class-name ,entity))
+ ,service))
+
+(defsubst luna-send (entity message &rest luna-current-method-arguments)
+ "Send MESSAGE to ENTITY, and return the result.
+ENTITY is an instance of a luna class, and MESSAGE is a method name of
+the luna class.
+LUNA-CURRENT-METHOD-ARGUMENTS is arguments of the MESSAGE."
+ (let ((luna-next-methods (luna-find-functions entity message))
+ luna-current-method
+ luna-previous-return-value)
+ (while (and luna-next-methods
+ (progn
+ (setq luna-current-method (pop luna-next-methods)
+ luna-previous-return-value
+ (apply luna-current-method
+ luna-current-method-arguments))
+ (if (symbolp luna-current-method)
+ (not (eq (get luna-current-method
+ 'luna-method-qualifier) :around))
+ t))))
+ luna-previous-return-value))
+
+(eval-when-compile
+ (defvar luna-next-methods nil)
+ (defvar luna-current-method-arguments nil))
+
+(defun luna-call-next-method ()
+ "Call the next method in the current method function.
+A method function that has :around qualifier should call this function
+to execute the parents' methods."
+ (let (luna-current-method
+ luna-previous-return-value)
+ (while (and luna-next-methods
+ (progn
+ (setq luna-current-method (pop luna-next-methods)
+ luna-previous-return-value
+ (apply luna-current-method
+ luna-current-method-arguments))
+ (if (symbolp luna-current-method)
+ (not (eq (get luna-current-method
+ 'luna-method-qualifier) :around))
+ t))))
+ luna-previous-return-value))
+
+(defun luna-make-entity (class &rest init-args)
+ "Make an entity (instance) of luna-class CLASS and return it.
+INIT-ARGS is a plist of the form (:SLOT1 VAL1 :SLOT2 VAL2 ...),
+where SLOTs are slots of CLASS and the VALs are initial values of
+the corresponding SLOTs."
+ (let* ((c (get class 'luna-class))
+ (v (make-vector (luna-class-number-of-slots c) nil)))
+ (luna-set-class-name v class)
(luna-set-obarray v (make-vector 7 0))
- (while init-args
- (setq s (intern-soft (substring (symbol-name (pop init-args)) 1) oa)
- i (pop init-args))
- (if s
- (aset v (get s 'luna-slot-index) i)
- ))
- (luna-send v 'initialize-instance v)
- v))
+ (apply #'luna-send v 'initialize-instance v init-args)))
+
+
+;;; @ interface (generic function)
+;;;
+
+;; Find a method of ENTITY that handles MESSAGE, and call it with
+;; arguments LUNA-CURRENT-METHOD-ARGUMENTS.
+
+(defun luna-apply-generic (entity message &rest luna-current-method-arguments)
+ (let* ((class (luna-class-name entity))
+ (cache (get message 'luna-method-cache))
+ (sym (intern-soft (symbol-name class) cache))
+ luna-next-methods)
+ (if sym
+ (setq luna-next-methods (symbol-value sym))
+ (setq luna-next-methods
+ (luna-find-functions entity message))
+ (set (intern (symbol-name class) cache)
+ luna-next-methods))
+ (luna-call-next-method)))
+
+
+;; Convert ARGLIST (argument list spec for a method function) to the
+;; actual list of arguments.
(defsubst luna-arglist-to-arguments (arglist)
(let (dest)
(while arglist
(let ((arg (car arglist)))
(or (memq arg '(&optional &rest))
- (setq dest (cons arg dest)))
- )
+ (setq dest (cons arg dest))))
(setq arglist (cdr arglist)))
(nreverse dest)))
+
(defmacro luna-define-generic (name args &optional doc)
- "Define generic-function NAME.
-ARGS is argument of and DOC is DOC-string."
+ "Define a function NAME that provides a generic interface to the method NAME.
+ARGS is the argument list for NAME. The first element of ARGS is an
+entity.
+
+The function handles a message sent to the entity by calling the
+method with proper arguments.
+
+The optional 3rd argument DOC is the documentation string for NAME."
(if doc
- `(defun ,(intern (symbol-name name)) ,args
- ,doc
- (luna-send ,(car args) ',name
- ,@(luna-arglist-to-arguments args))
- )
- `(defun ,(intern (symbol-name name)) ,args
- (luna-send ,(car args) ',name
- ,@(luna-arglist-to-arguments args))
- )))
+ `(progn
+ (defun ,(intern (symbol-name name)) ,args
+ ,doc
+ (luna-apply-generic ,(car args) ',name
+ ,@(luna-arglist-to-arguments args)))
+ (put ',name 'luna-method-cache (make-vector 31 0)))
+ `(progn
+ (defun ,(intern (symbol-name name)) ,args
+ (luna-apply-generic ,(car args) ',name
+ ,@(luna-arglist-to-arguments args)))
+ (put ',name 'luna-method-cache (make-vector 31 0)))))
(put 'luna-define-generic 'lisp-indent-function 'defun)
+
+;;; @ accessor
+;;;
+
(defun luna-define-internal-accessors (class-name)
- "Define internal accessors for an entity of CLASS-NAME."
+ "Define internal accessors for instances of the luna class CLASS-NAME.
+
+Internal accessors are macros to refer and set a slot value of the
+instances. For instance, if the class has SLOT, macros
+CLASS-NAME-SLOT-internal and CLASS-NAME-set-SLOT-internal are defined.
+
+CLASS-NAME-SLOT-internal accepts one argument INSTANCE, and returns
+the value of SLOT.
+
+CLASS-NAME-set-SLOT-internal accepts two arguemnt INSTANCE and VALUE,
+and sets SLOT to VALUE."
(let ((entity-class (luna-find-class class-name))
parents parent-class)
(mapatoms
(setq parent-class (luna-find-class (car parents)))
(if (luna-class-slot-index parent-class slot)
(throw 'derived nil))
- (setq parents (cdr parents))
- )
+ (setq parents (cdr parents)))
(eval
`(progn
(defmacro ,(intern (format "%s-%s-internal"
(entity)
(list 'aref entity
,(luna-class-slot-index entity-class
- (intern (symbol-name slot)))
- ))
+ (intern (symbol-name slot)))))
(defmacro ,(intern (format "%s-set-%s-internal"
class-name slot))
(entity value)
(list 'aset entity
,(luna-class-slot-index
entity-class (intern (symbol-name slot)))
- value))
- ))
- )))
+ value)))))))
(luna-class-obarray entity-class))))
-
+
+
+;;; @ standard object
+;;;
+
+;; Define super class of all luna classes.
+(luna-define-class-function 'standard-object)
+
+(luna-define-method initialize-instance ((entity standard-object)
+ &rest init-args)
+ "Initialize slots of ENTITY by INIT-ARGS."
+ (let* ((c (luna-find-class (luna-class-name entity)))
+ (oa (luna-class-obarray c))
+ s i)
+ (while init-args
+ (setq s (intern-soft (substring (symbol-name (pop init-args)) 1) oa)
+ i (pop init-args))
+ (if s
+ (aset entity (get s 'luna-slot-index) i)))
+ entity))
+
;;; @ end
;;;