summaryrefslogtreecommitdiffstats
path: root/yasyn.scm
blob: 2b3cec0941662a4fed14ecf2788c78a93d586932 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
;;"yasyn.scm" YASOS in terms of "object.scm"
;;;From: whumeniu@datap.ca (Wade Humeniuk)

(require 'object)

(define yasos:instance?     object?)
;; Removed (define yasos:make-instance 'bogus)  ;;
;; Removed (define-syntax YASOS:INSTANCE-DISPATCHER  ;; alias so compiler can inline for speed
;;   (syntax-rules () ((yasos:instance-dispatcher inst) (cdr inst))))
;; DEFINE-OPERATION

(define-syntax define-operation
  (syntax-rules ()
    ((define-operation (<name> <inst> <arg> ...) <exp1> <exp2> ...)
     ;;=>
     (define <name> (make-generic-method
		     (lambda (<inst> <arg> ...) <exp1> <exp2> ...))))

    ((define-operation (<name> <inst> <arg> ...) ) ;; no body
     ;;=>
     (define-operation (<name> <inst> <arg> ...)
       (slib:error "Operation not handled"
		   '<name>
		   (format #f (if (yasos:instance? <inst>) "#<INSTANCE>" "~s")
			   <inst>))))))

;; DEFINE-PREDICATE

(define-syntax define-predicate
  (syntax-rules ()
    ((define-predicate <name>)
     ;;=>
     (define <name> (make-generic-predicate)))))

;; OBJECT

(define-syntax object
  (syntax-rules ()
    ((object ((<name> <self> <arg> ...) <exp1> <exp2> ...) ...)
    ;;=>
     (let ((self (make-object)))
       (make-method! self <name> (lambda (<self> <arg> ...) <exp1> <exp2> ...))
       ...
       self))))

;; OBJECT with MULTIPLE INHERITANCE  {First Found Rule}

(define-syntax object-with-ancestors
  (syntax-rules ()
    ((object-with-ancestors ( (<ancestor1> <init1>) ... )
			    ((<name> <self> <arg> ...) <exp1> <exp2> ...) ...)
    ;;=>
     (let* ((<ancestor1> <init1>)
	    ...
	    (self (make-object <ancestor1> ...)))
       (make-method! self <name> (lambda (<self> <arg> ...) <exp1> <exp2> ...))
       ...
       self))))

;; OPERATE-AS  {a.k.a. send-to-super}

; used in operations/methods

(define-syntax operate-as
  (syntax-rules ()
   ((operate-as <component> <op> <composit> <arg> ...) ;; What is <composit> ???
   ;;=>
    ((get-method <component> <op>) <composit> <arg> ...))))



;; SET & SETTER


(define-syntax set
  (syntax-rules ()
    ((set (<access> <index> ...) <newval>)
     ((yasos:setter <access>) <index> ... <newval>)
    )
    ((set <var> <newval>)
     (set! <var> <newval>)
    )
) )


(define yasos:add-setter	'bogus)
(define yasos:remove-setter-for 'bogus)

(define yasos:setter
  (let ( (known-setters (list (cons car set-car!)
			      (cons cdr set-cdr!)
			      (cons vector-ref vector-set!)
			      (cons string-ref string-set!))
	 )
	 (added-setters '())
       )

    (set! yasos:add-setter
      (lambda (getter setter)
	(set! added-setters (cons (cons getter setter) added-setters)))
    )
    (set! yasos:remove-setter-for
      (lambda (getter)
	(cond
	  ((null? added-setters)
	   (slib:error "REMOVE-SETTER-FOR: Unknown getter" getter)
	  )
	  ((eq? getter (caar added-setters))
	   (set! added-setters (cdr added-setters))
	  )
	  (else
	    (let loop ((x added-setters) (y (cdr added-setters)))
	      (cond
		((null? y) (slib:error "REMOVE-SETTER-FOR: Unknown getter"
				       getter))
		((eq? getter (caar y)) (set-cdr! x (cdr y)))
		(else (loop (cdr x) (cdr y)))
	  ) ) )
     ) ) )

    (letrec ( (self
		 (lambda (proc-or-operation)
		   (cond ((assq proc-or-operation known-setters) => cdr)
			 ((assq proc-or-operation added-setters) => cdr)
			 (else (proc-or-operation self))) )
	    ) )
      self)
) )



(define (yasos:make-access-operation <name>)
  (letrec ( (setter-dispatch
	       (lambda (inst . args)
		   (cond
		     ((and (yasos:instance? inst)
			   (get-method inst setter-dispatch))
		       => (lambda (method) (apply method (cons inst args)))
		     )
		     (else #f)))
	    )
	    (self
	       (lambda (inst . args)
		  (cond
		     ((eq? inst yasos:setter) setter-dispatch) ; for (setter self)
		     ((and (yasos:instance? inst)
			   (get-method inst self))
		      => (lambda (method) (apply method (cons inst args)))
		     )
		     (else (slib:error "Operation not handled" <name> inst))
		)  )
	    )
	  )

	  self
) )

(define-syntax define-access-operation
  (syntax-rules ()
    ((define-access-operation <name>)
     ;=>
     (define <name> (yasos:make-access-operation '<name>))
) ) )



;;---------------------
;; general operations
;;---------------------

(define-operation (yasos:print obj port)
  (format port
	  ;; if an instance does not have a PRINT operation..
	  (if (yasos:instance? obj) "#<INSTANCE>" "~s")
	  obj
) )

(define-operation (yasos:size obj)
  ;; default behavior
  (cond
    ((vector? obj) (vector-length obj))
    ((list?   obj) (length obj))
    ((pair?   obj) 2)
    ((string? obj) (string-length obj))
    ((char?   obj) 1)
    (else
      (slib:error "Operation not supported: size" obj))
) )

(require 'format)

;;; exports:

(define print yasos:print)		; print also in debug.scm
(define size yasos:size)
(define add-setter yasos:add-setter)
(define remove-setter-for yasos:remove-setter-for)
(define setter yasos:setter)

(provide 'oop)				;in case we were loaded this way.
(provide 'yasos)