1 665c255d 2023-08-04 jrmu (define (ambeval exp env succeed fail)
2 665c255d 2023-08-04 jrmu ((analyze exp) env succeed fail))
3 665c255d 2023-08-04 jrmu (define (analyze exp)
4 665c255d 2023-08-04 jrmu (cond ((self-evaluating? exp)
5 665c255d 2023-08-04 jrmu (analyze-self-evaluating exp))
6 665c255d 2023-08-04 jrmu ((quoted? exp) (analyze-quoted exp))
7 665c255d 2023-08-04 jrmu ((variable? exp) (analyze-variable exp))
8 665c255d 2023-08-04 jrmu ((assignment? exp) (analyze-assignment exp))
9 665c255d 2023-08-04 jrmu ((definition? exp) (analyze-definition exp))
10 665c255d 2023-08-04 jrmu ((if? exp) (analyze-if exp))
11 665c255d 2023-08-04 jrmu ((and? exp) (analyze (and->if exp)))
12 665c255d 2023-08-04 jrmu ((or? exp) (analyze (or->if exp)))
13 665c255d 2023-08-04 jrmu ((lambda? exp) (analyze-lambda exp))
14 665c255d 2023-08-04 jrmu ((let? exp) (analyze (let->combination exp)))
15 665c255d 2023-08-04 jrmu ((let*? exp) (analyze (let*->nested-lets exp)))
16 665c255d 2023-08-04 jrmu ((named-let? exp) (analyze (named-let->combination exp)))
17 665c255d 2023-08-04 jrmu ((letrec? exp) (analyze (letrec->let exp)))
18 665c255d 2023-08-04 jrmu ((do? exp) (analyze (do->combination exp)))
19 665c255d 2023-08-04 jrmu ((begin? exp) (analyze-sequence (begin-actions exp)))
20 665c255d 2023-08-04 jrmu ((cond? exp) (analyze (cond->if exp)))
21 665c255d 2023-08-04 jrmu ((amb? exp) (analyze-amb exp))
22 665c255d 2023-08-04 jrmu ((application? exp) (analyze-application exp))
24 665c255d 2023-08-04 jrmu (error "Unknown expression type -- ANALYZE" exp))))
27 665c255d 2023-08-04 jrmu ;; analyzing procedures
28 665c255d 2023-08-04 jrmu (define (analyze-self-evaluating exp)
29 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
30 665c255d 2023-08-04 jrmu (succeed exp fail)))
31 665c255d 2023-08-04 jrmu (define (analyze-quoted exp)
32 665c255d 2023-08-04 jrmu (let ((qval (text-of-quotation exp)))
33 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
34 665c255d 2023-08-04 jrmu (succeed qval fail))))
35 665c255d 2023-08-04 jrmu (define (analyze-variable exp)
36 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
37 665c255d 2023-08-04 jrmu (succeed (lookup-variable-value exp env)
39 665c255d 2023-08-04 jrmu (define (analyze-lambda exp)
40 665c255d 2023-08-04 jrmu (let ((vars (lambda-parameters exp))
41 665c255d 2023-08-04 jrmu ;; (bproc (analyze-sequence (scan-out-defines (lambda-body exp)))))
42 665c255d 2023-08-04 jrmu (bproc (analyze-sequence (lambda-body exp))))
43 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
44 665c255d 2023-08-04 jrmu (succeed (make-procedure vars bproc env)
46 665c255d 2023-08-04 jrmu (define (analyze-if exp)
47 665c255d 2023-08-04 jrmu (let ((pproc (analyze (if-predicate exp)))
48 665c255d 2023-08-04 jrmu (cproc (analyze (if-consequent exp)))
49 665c255d 2023-08-04 jrmu (aproc (analyze (if-alternative exp))))
50 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
52 665c255d 2023-08-04 jrmu ;; success continuation for evaluating the predicate
53 665c255d 2023-08-04 jrmu ;; to obtain pred-value
54 665c255d 2023-08-04 jrmu (lambda (pred-value fail2)
55 665c255d 2023-08-04 jrmu (if (true? pred-value)
56 665c255d 2023-08-04 jrmu (cproc env succeed fail2)
57 665c255d 2023-08-04 jrmu (aproc env succeed fail2)))
58 665c255d 2023-08-04 jrmu ;; failure continuation for evaluating the predicate
60 665c255d 2023-08-04 jrmu (define (analyze-sequence exps)
61 665c255d 2023-08-04 jrmu (define (sequentially a b)
62 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
64 665c255d 2023-08-04 jrmu ;; success continuation for calling a
65 665c255d 2023-08-04 jrmu (lambda (a-value fail2)
66 665c255d 2023-08-04 jrmu (b env succeed fail2))
67 665c255d 2023-08-04 jrmu ;; failure continuation for calling a
69 665c255d 2023-08-04 jrmu (define (loop first-proc rest-procs)
70 665c255d 2023-08-04 jrmu (if (null? rest-procs)
72 665c255d 2023-08-04 jrmu (loop (sequentially first-proc (car rest-procs))
73 665c255d 2023-08-04 jrmu (cdr rest-procs))))
74 665c255d 2023-08-04 jrmu (let ((procs (map analyze exps)))
75 665c255d 2023-08-04 jrmu (if (null? procs)
76 665c255d 2023-08-04 jrmu (error "Empty sequence -- ANALYZE"))
77 665c255d 2023-08-04 jrmu (loop (car procs) (cdr procs))))
78 665c255d 2023-08-04 jrmu (define (analyze-definition exp)
79 665c255d 2023-08-04 jrmu (let ((var (definition-variable exp))
80 665c255d 2023-08-04 jrmu (vproc (analyze (definition-value exp))))
81 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
83 665c255d 2023-08-04 jrmu (lambda (val fail2)
84 665c255d 2023-08-04 jrmu (define-variable! var val env)
85 665c255d 2023-08-04 jrmu (succeed 'ok fail2))
87 665c255d 2023-08-04 jrmu (define (analyze-assignment exp)
88 665c255d 2023-08-04 jrmu (let ((var (assignment-variable exp))
89 665c255d 2023-08-04 jrmu (vproc (analyze (assignment-value exp))))
90 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
92 665c255d 2023-08-04 jrmu (lambda (val fail2) ; *1*
93 665c255d 2023-08-04 jrmu (let ((old-value
94 665c255d 2023-08-04 jrmu (lookup-variable-value var env)))
95 665c255d 2023-08-04 jrmu (set-variable-value! var val env)
96 665c255d 2023-08-04 jrmu (succeed 'ok
97 665c255d 2023-08-04 jrmu (lambda () ; *2*
98 665c255d 2023-08-04 jrmu (set-variable-value! var
101 665c255d 2023-08-04 jrmu (fail2)))))
104 665c255d 2023-08-04 jrmu (define (analyze-application exp)
105 665c255d 2023-08-04 jrmu (let ((fproc (analyze (operator exp)))
106 665c255d 2023-08-04 jrmu (aprocs (map analyze (operands exp))))
107 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
109 665c255d 2023-08-04 jrmu (lambda (proc fail2)
110 665c255d 2023-08-04 jrmu (get-args aprocs
112 665c255d 2023-08-04 jrmu (lambda (args fail3)
113 665c255d 2023-08-04 jrmu (execute-application
114 665c255d 2023-08-04 jrmu proc args succeed fail3))
117 665c255d 2023-08-04 jrmu (define (get-args aprocs env succeed fail)
118 665c255d 2023-08-04 jrmu (if (null? aprocs)
119 665c255d 2023-08-04 jrmu (succeed '() fail)
120 665c255d 2023-08-04 jrmu ((car aprocs) env
121 665c255d 2023-08-04 jrmu ;; success continuation for this aproc
122 665c255d 2023-08-04 jrmu (lambda (arg fail2)
123 665c255d 2023-08-04 jrmu (get-args (cdr aprocs)
125 665c255d 2023-08-04 jrmu ;; success continuation for recursive
126 665c255d 2023-08-04 jrmu ;; call to get-args
127 665c255d 2023-08-04 jrmu (lambda (args fail3)
128 665c255d 2023-08-04 jrmu (succeed (cons arg args)
133 665c255d 2023-08-04 jrmu (define (analyze-amb exp)
134 665c255d 2023-08-04 jrmu (let ((cprocs (map analyze (amb-choices exp))))
135 665c255d 2023-08-04 jrmu (lambda (env succeed fail)
136 665c255d 2023-08-04 jrmu (define (try-next choices)
137 665c255d 2023-08-04 jrmu (if (null? choices)
139 665c255d 2023-08-04 jrmu ((car choices) env
142 665c255d 2023-08-04 jrmu (try-next (cdr choices))))))
143 665c255d 2023-08-04 jrmu (try-next cprocs))))
150 665c255d 2023-08-04 jrmu (define (tagged-list? exp tag)
151 665c255d 2023-08-04 jrmu (if (pair? exp)
152 665c255d 2023-08-04 jrmu (eq? (car exp) tag)
156 665c255d 2023-08-04 jrmu (define (amb? exp) (tagged-list? exp 'amb))
157 665c255d 2023-08-04 jrmu (define (amb-choices exp) (cdr exp))
159 665c255d 2023-08-04 jrmu ;; self-evaluating/variable/quoted
160 665c255d 2023-08-04 jrmu (define (self-evaluating? exp)
161 665c255d 2023-08-04 jrmu (cond ((number? exp) true)
162 665c255d 2023-08-04 jrmu ((string? exp) true)
163 665c255d 2023-08-04 jrmu (else false)))
164 665c255d 2023-08-04 jrmu (define (variable? exp) (symbol? exp))
165 665c255d 2023-08-04 jrmu (define (quoted? exp)
166 665c255d 2023-08-04 jrmu (tagged-list? exp 'quote))
167 665c255d 2023-08-04 jrmu (define (text-of-quotation exp) (cadr exp))
169 665c255d 2023-08-04 jrmu ;; assignment/definition
170 665c255d 2023-08-04 jrmu (define (assignment? exp)
171 665c255d 2023-08-04 jrmu (tagged-list? exp 'set!))
172 665c255d 2023-08-04 jrmu (define (assignment-variable exp) (cadr exp))
173 665c255d 2023-08-04 jrmu (define (assignment-value exp) (caddr exp))
174 665c255d 2023-08-04 jrmu (define (make-assignment var val)
175 665c255d 2023-08-04 jrmu (list 'set! var val))
176 665c255d 2023-08-04 jrmu (define (definition? exp)
177 665c255d 2023-08-04 jrmu (tagged-list? exp 'define))
178 665c255d 2023-08-04 jrmu (define (definition-variable exp)
179 665c255d 2023-08-04 jrmu (if (symbol? (cadr exp))
181 665c255d 2023-08-04 jrmu (caadr exp)))
182 665c255d 2023-08-04 jrmu (define (definition-value exp)
183 665c255d 2023-08-04 jrmu (if (symbol? (cadr exp))
184 665c255d 2023-08-04 jrmu (caddr exp)
185 665c255d 2023-08-04 jrmu (make-lambda (cdadr exp) ; formal parameters
186 665c255d 2023-08-04 jrmu (cddr exp)))) ; body
187 665c255d 2023-08-04 jrmu (define (make-definition var val)
188 665c255d 2023-08-04 jrmu `(define ,var ,val))
190 665c255d 2023-08-04 jrmu ;; if/and/or
191 665c255d 2023-08-04 jrmu (define (if? exp) (tagged-list? exp 'if))
192 665c255d 2023-08-04 jrmu (define (if-predicate exp) (cadr exp))
193 665c255d 2023-08-04 jrmu (define (if-consequent exp) (caddr exp))
194 665c255d 2023-08-04 jrmu (define (if-alternative exp)
195 665c255d 2023-08-04 jrmu (if (not (null? (cdddr exp)))
196 665c255d 2023-08-04 jrmu (cadddr exp)
198 665c255d 2023-08-04 jrmu (define (make-if predicate consequent alternative)
199 665c255d 2023-08-04 jrmu (list 'if predicate consequent alternative))
201 665c255d 2023-08-04 jrmu (define (and? exp)
202 665c255d 2023-08-04 jrmu (tagged-list? exp 'and))
203 665c255d 2023-08-04 jrmu (define (and-clauses exp)
205 665c255d 2023-08-04 jrmu (define (or? exp)
206 665c255d 2023-08-04 jrmu (tagged-list? exp 'or))
207 665c255d 2023-08-04 jrmu (define (or-clauses exp)
209 665c255d 2023-08-04 jrmu (define (and->if exp)
210 665c255d 2023-08-04 jrmu (define (expand-clauses clauses)
211 665c255d 2023-08-04 jrmu (cond ((null? clauses) 'true)
212 665c255d 2023-08-04 jrmu ((null? (cdr clauses)) (car clauses))
213 665c255d 2023-08-04 jrmu (else (make-if (car clauses)
214 665c255d 2023-08-04 jrmu (expand-clauses (cdr clauses))
216 665c255d 2023-08-04 jrmu (expand-clauses (and-clauses exp)))
217 665c255d 2023-08-04 jrmu (define (or->if exp)
218 665c255d 2023-08-04 jrmu (define (expand-clauses clauses)
219 665c255d 2023-08-04 jrmu (if (null? clauses)
221 665c255d 2023-08-04 jrmu (make-if (car clauses)
222 665c255d 2023-08-04 jrmu (car clauses)
223 665c255d 2023-08-04 jrmu (expand-clauses (cdr clauses)))))
224 665c255d 2023-08-04 jrmu (expand-clauses (or-clauses exp)))
226 665c255d 2023-08-04 jrmu ;; lambda/let/let*/letrec
227 665c255d 2023-08-04 jrmu (define (lambda? exp) (tagged-list? exp 'lambda))
228 665c255d 2023-08-04 jrmu (define (lambda-parameters exp) (cadr exp))
229 665c255d 2023-08-04 jrmu (define (lambda-body exp) (cddr exp))
230 665c255d 2023-08-04 jrmu (define (make-lambda parameters body)
231 665c255d 2023-08-04 jrmu (cons 'lambda (cons parameters body)))
233 665c255d 2023-08-04 jrmu (define (make-let vars vals body)
235 665c255d 2023-08-04 jrmu (cons (map list vars vals)
237 665c255d 2023-08-04 jrmu (define (let? exp)
238 665c255d 2023-08-04 jrmu (and (tagged-list? exp 'let)
239 665c255d 2023-08-04 jrmu (not (symbol? (cadr exp)))))
240 665c255d 2023-08-04 jrmu (define (let-vars exp)
241 665c255d 2023-08-04 jrmu (map car (cadr exp)))
242 665c255d 2023-08-04 jrmu (define (let-vals exp)
243 665c255d 2023-08-04 jrmu (map cadr (cadr exp)))
244 665c255d 2023-08-04 jrmu (define (let-body exp)
245 665c255d 2023-08-04 jrmu (cddr exp))
246 665c255d 2023-08-04 jrmu (define (let->combination exp)
247 665c255d 2023-08-04 jrmu (make-application (make-lambda (let-vars exp) (let-body exp))
248 665c255d 2023-08-04 jrmu (let-vals exp)))
249 665c255d 2023-08-04 jrmu (define (named-let? exp)
250 665c255d 2023-08-04 jrmu (and (tagged-list? exp 'let)
251 665c255d 2023-08-04 jrmu (symbol? (cadr exp))))
252 665c255d 2023-08-04 jrmu (define (named-let-name exp)
253 665c255d 2023-08-04 jrmu (cadr exp))
254 665c255d 2023-08-04 jrmu (define (named-let-vars exp)
255 665c255d 2023-08-04 jrmu (map car (caddr exp)))
256 665c255d 2023-08-04 jrmu (define (named-let-vals exp)
257 665c255d 2023-08-04 jrmu (map cadr (caddr exp)))
258 665c255d 2023-08-04 jrmu (define (named-let-body exp)
259 665c255d 2023-08-04 jrmu (cdddr exp))
260 665c255d 2023-08-04 jrmu (define (named-let->combination exp)
261 665c255d 2023-08-04 jrmu (sequence->exp
262 665c255d 2023-08-04 jrmu (list (make-definition (named-let-name exp)
263 665c255d 2023-08-04 jrmu (make-lambda (named-let-vars exp)
264 665c255d 2023-08-04 jrmu (named-let-body exp)))
265 665c255d 2023-08-04 jrmu (make-application (named-let-name exp)
266 665c255d 2023-08-04 jrmu (named-let-vals exp)))))
267 665c255d 2023-08-04 jrmu (define (make-named-let name vars vals body)
270 665c255d 2023-08-04 jrmu (cons (map list vars vals)
273 665c255d 2023-08-04 jrmu (define (letrec? exp)
274 665c255d 2023-08-04 jrmu (tagged-list? exp 'letrec))
276 665c255d 2023-08-04 jrmu (define (letrec-vars exp)
277 665c255d 2023-08-04 jrmu (map car (cadr exp)))
278 665c255d 2023-08-04 jrmu (define (letrec-vals exp)
279 665c255d 2023-08-04 jrmu (map cadr (cadr exp)))
280 665c255d 2023-08-04 jrmu (define (letrec-body exp)
281 665c255d 2023-08-04 jrmu (cddr exp))
282 665c255d 2023-08-04 jrmu (define (letrec->let exp)
283 665c255d 2023-08-04 jrmu (let* ((vars (letrec-vars exp))
284 665c255d 2023-08-04 jrmu (unassigneds (map (lambda (var) ''*unassigned*)
286 665c255d 2023-08-04 jrmu (vals (letrec-vals exp))
287 665c255d 2023-08-04 jrmu (assignments (map (lambda (var val)
288 665c255d 2023-08-04 jrmu (make-assignment var val))
291 665c255d 2023-08-04 jrmu (body (letrec-body exp)))
292 665c255d 2023-08-04 jrmu (make-let vars
293 665c255d 2023-08-04 jrmu unassigneds
294 665c255d 2023-08-04 jrmu (append assignments body))))
296 665c255d 2023-08-04 jrmu (define (make-application op args)
297 665c255d 2023-08-04 jrmu (cons op args))
299 665c255d 2023-08-04 jrmu (define (let*? exp)
300 665c255d 2023-08-04 jrmu (tagged-list? exp 'let*))
301 665c255d 2023-08-04 jrmu (define let*-vars let-vars)
302 665c255d 2023-08-04 jrmu (define let*-vals let-vals)
303 665c255d 2023-08-04 jrmu (define let*-body let-body)
304 665c255d 2023-08-04 jrmu (define (let*->nested-lets exp)
305 665c255d 2023-08-04 jrmu (define (expand-lets vars vals)
306 665c255d 2023-08-04 jrmu (if (null? (cdr vars))
307 665c255d 2023-08-04 jrmu (make-let (list (car vars))
308 665c255d 2023-08-04 jrmu (list (car vals))
309 665c255d 2023-08-04 jrmu (let*-body exp))
310 665c255d 2023-08-04 jrmu (make-let (list (car vars))
311 665c255d 2023-08-04 jrmu (list (car vals))
312 665c255d 2023-08-04 jrmu (list (expand-lets (cdr vars) (cdr vals))))))
313 665c255d 2023-08-04 jrmu (let ((vars (let*-vars exp))
314 665c255d 2023-08-04 jrmu (vals (let*-vals exp)))
315 665c255d 2023-08-04 jrmu (if (null? vars)
316 665c255d 2023-08-04 jrmu (sequence->exp (let*-body exp))
317 665c255d 2023-08-04 jrmu (expand-lets vars vals))))
320 665c255d 2023-08-04 jrmu (define (do? exp)
321 665c255d 2023-08-04 jrmu (tagged-list? exp 'do))
322 665c255d 2023-08-04 jrmu (define (do-vars exp)
323 665c255d 2023-08-04 jrmu (map car (cadr exp)))
324 665c255d 2023-08-04 jrmu (define (do-inits exp)
325 665c255d 2023-08-04 jrmu (map cadr (cadr exp)))
326 665c255d 2023-08-04 jrmu (define (do-steps exp)
327 665c255d 2023-08-04 jrmu (map (lambda (var-init-step)
328 665c255d 2023-08-04 jrmu (if (null? (cddr var-init-step))
329 665c255d 2023-08-04 jrmu (car var-init-step)
330 665c255d 2023-08-04 jrmu (caddr var-init-step)))
331 665c255d 2023-08-04 jrmu (cadr exp)))
332 665c255d 2023-08-04 jrmu (define (do-test exp)
333 665c255d 2023-08-04 jrmu (caaddr exp))
334 665c255d 2023-08-04 jrmu (define (do-expressions exp)
335 665c255d 2023-08-04 jrmu (if (null? (cdaddr exp))
336 665c255d 2023-08-04 jrmu (caddr exp)
337 665c255d 2023-08-04 jrmu (cdaddr exp)))
338 665c255d 2023-08-04 jrmu (define (do-commands exp)
339 665c255d 2023-08-04 jrmu (cdddr exp))
340 665c255d 2023-08-04 jrmu (define (do->combination exp)
341 665c255d 2023-08-04 jrmu (make-named-let
343 665c255d 2023-08-04 jrmu (do-vars exp)
344 665c255d 2023-08-04 jrmu (do-inits exp)
347 665c255d 2023-08-04 jrmu (do-test exp)
348 665c255d 2023-08-04 jrmu (sequence->exp (do-expressions exp))
349 665c255d 2023-08-04 jrmu (sequence->exp
350 665c255d 2023-08-04 jrmu (append (do-commands exp)
351 665c255d 2023-08-04 jrmu (list (make-application
353 665c255d 2023-08-04 jrmu (do-steps exp)))))))))
356 665c255d 2023-08-04 jrmu ;; begin/sequence
357 665c255d 2023-08-04 jrmu (define (begin? exp) (tagged-list? exp 'begin))
358 665c255d 2023-08-04 jrmu (define (begin-actions exp) (cdr exp))
359 665c255d 2023-08-04 jrmu (define (last-exp? seq) (null? (cdr seq)))
360 665c255d 2023-08-04 jrmu (define (first-exp seq) (car seq))
361 665c255d 2023-08-04 jrmu (define (rest-exps seq) (cdr seq))
362 665c255d 2023-08-04 jrmu (define (sequence->exp seq)
363 665c255d 2023-08-04 jrmu (cond ((null? seq) seq)
364 665c255d 2023-08-04 jrmu ((last-exp? seq) (first-exp seq))
365 665c255d 2023-08-04 jrmu (else (make-begin seq))))
366 665c255d 2023-08-04 jrmu (define (make-begin seq) (cons 'begin seq))
368 665c255d 2023-08-04 jrmu ;; application
369 665c255d 2023-08-04 jrmu (define (application? exp) (pair? exp))
370 665c255d 2023-08-04 jrmu (define (operator exp) (car exp))
371 665c255d 2023-08-04 jrmu (define (operands exp) (cdr exp))
372 665c255d 2023-08-04 jrmu (define (no-operands? ops) (null? ops))
373 665c255d 2023-08-04 jrmu (define (first-operand ops) (car ops))
374 665c255d 2023-08-04 jrmu (define (rest-operands ops) (cdr ops))
377 665c255d 2023-08-04 jrmu (define (cond? exp) (tagged-list? exp 'cond))
378 665c255d 2023-08-04 jrmu (define (cond-clauses exp) (cdr exp))
379 665c255d 2023-08-04 jrmu (define (cond-else-clause? clause)
380 665c255d 2023-08-04 jrmu (eq? (cond-predicate clause) 'else))
381 665c255d 2023-08-04 jrmu (define (cond-predicate clause) (car clause))
382 665c255d 2023-08-04 jrmu (define (cond-actions clause) (cdr clause))
383 665c255d 2023-08-04 jrmu (define (cond-extended-clause? clause)
384 665c255d 2023-08-04 jrmu (and (not (null? (cdr clause))) (eq? (cadr clause) '=>)))
385 665c255d 2023-08-04 jrmu (define (cond-extended-proc clause)
386 665c255d 2023-08-04 jrmu (caddr clause))
387 665c255d 2023-08-04 jrmu (define (cond->if exp)
388 665c255d 2023-08-04 jrmu (expand-clauses (cond-clauses exp)))
389 665c255d 2023-08-04 jrmu (define (expand-clauses clauses)
390 665c255d 2023-08-04 jrmu (if (null? clauses)
391 665c255d 2023-08-04 jrmu 'false ; no else clause
392 665c255d 2023-08-04 jrmu (let ((first (car clauses))
393 665c255d 2023-08-04 jrmu (rest (cdr clauses)))
394 665c255d 2023-08-04 jrmu (if (cond-else-clause? first)
395 665c255d 2023-08-04 jrmu (if (null? rest)
396 665c255d 2023-08-04 jrmu (sequence->exp (cond-actions first))
397 665c255d 2023-08-04 jrmu (error "ELSE clause isn't last -- COND->IF"
399 665c255d 2023-08-04 jrmu (if (cond-extended-clause? first)
400 665c255d 2023-08-04 jrmu (make-if (cond-predicate first)
401 665c255d 2023-08-04 jrmu (make-application
402 665c255d 2023-08-04 jrmu (cond-extended-proc first)
403 665c255d 2023-08-04 jrmu (list (cond-predicate first)))
404 665c255d 2023-08-04 jrmu (expand-clauses rest))
405 665c255d 2023-08-04 jrmu (make-if (cond-predicate first)
406 665c255d 2023-08-04 jrmu (sequence->exp (cond-actions first))
407 665c255d 2023-08-04 jrmu (expand-clauses rest)))))))
408 665c255d 2023-08-04 jrmu (define (true? x)
409 665c255d 2023-08-04 jrmu (not (eq? x false)))
410 665c255d 2023-08-04 jrmu (define (false? x)
411 665c255d 2023-08-04 jrmu (eq? x false))
413 665c255d 2023-08-04 jrmu ;; procedure
414 665c255d 2023-08-04 jrmu (define (make-procedure parameters body env)
415 665c255d 2023-08-04 jrmu (list 'procedure parameters body env))
416 665c255d 2023-08-04 jrmu (define (scan-out-defines body)
417 665c255d 2023-08-04 jrmu (let* ((definitions (filter definition? body))
418 665c255d 2023-08-04 jrmu (vars (map definition-variable definitions))
419 665c255d 2023-08-04 jrmu (unassigneds (map (lambda (var) ''*unassigned*)
421 665c255d 2023-08-04 jrmu (vals (map definition-value definitions))
422 665c255d 2023-08-04 jrmu (assignments
423 665c255d 2023-08-04 jrmu (map (lambda (var val)
424 665c255d 2023-08-04 jrmu (make-assignment var val))
425 665c255d 2023-08-04 jrmu vars vals))
426 665c255d 2023-08-04 jrmu (exps (remove definition? body)))
427 665c255d 2023-08-04 jrmu (if (null? definitions)
430 665c255d 2023-08-04 jrmu (make-let vars
431 665c255d 2023-08-04 jrmu unassigneds
432 665c255d 2023-08-04 jrmu (append assignments exps))))))
433 665c255d 2023-08-04 jrmu (define (compound-procedure? p)
434 665c255d 2023-08-04 jrmu (tagged-list? p 'procedure))
435 665c255d 2023-08-04 jrmu (define (procedure-parameters p) (cadr p))
436 665c255d 2023-08-04 jrmu (define (procedure-body p) (caddr p))
437 665c255d 2023-08-04 jrmu (define (procedure-environment p) (cadddr p))
439 665c255d 2023-08-04 jrmu ;; environment
440 665c255d 2023-08-04 jrmu (define (enclosing-environment env) (cdr env))
441 665c255d 2023-08-04 jrmu (define (first-frame env) (car env))
442 665c255d 2023-08-04 jrmu (define the-empty-environment '())
443 665c255d 2023-08-04 jrmu (define (make-frame variables values)
444 665c255d 2023-08-04 jrmu (cons variables values))
445 665c255d 2023-08-04 jrmu (define (frame-variables frame) (car frame))
446 665c255d 2023-08-04 jrmu (define (frame-values frame) (cdr frame))
447 665c255d 2023-08-04 jrmu (define (add-binding-to-frame! var val frame)
448 665c255d 2023-08-04 jrmu (set-car! frame (cons var (car frame)))
449 665c255d 2023-08-04 jrmu (set-cdr! frame (cons val (cdr frame))))
450 665c255d 2023-08-04 jrmu (define (extend-environment vars vals base-env)
451 665c255d 2023-08-04 jrmu (if (= (length vars) (length vals))
452 665c255d 2023-08-04 jrmu (cons (make-frame vars vals) base-env)
453 665c255d 2023-08-04 jrmu (if (< (length vars) (length vals))
454 665c255d 2023-08-04 jrmu (error "Too many arguments supplied" vars vals)
455 665c255d 2023-08-04 jrmu (error "Too few arguments supplied" vars vals))))
456 665c255d 2023-08-04 jrmu (define (lookup-variable-value var env)
457 665c255d 2023-08-04 jrmu (define (env-loop env)
458 665c255d 2023-08-04 jrmu (define (scan vars vals)
459 665c255d 2023-08-04 jrmu (cond ((null? vars)
460 665c255d 2023-08-04 jrmu (env-loop (enclosing-environment env)))
461 665c255d 2023-08-04 jrmu ((eq? var (car vars))
462 665c255d 2023-08-04 jrmu (let ((val (car vals)))
463 665c255d 2023-08-04 jrmu (if (eq? val '*unassigned*)
464 665c255d 2023-08-04 jrmu (error "Var not yet defined -- LOOKUP-VARIABLE-VALUE" var)
466 665c255d 2023-08-04 jrmu (else (scan (cdr vars) (cdr vals)))))
467 665c255d 2023-08-04 jrmu (if (eq? env the-empty-environment)
468 665c255d 2023-08-04 jrmu (error "Unbound variable" var)
469 665c255d 2023-08-04 jrmu (let ((frame (first-frame env)))
470 665c255d 2023-08-04 jrmu (scan (frame-variables frame)
471 665c255d 2023-08-04 jrmu (frame-values frame)))))
472 665c255d 2023-08-04 jrmu (env-loop env))
473 665c255d 2023-08-04 jrmu (define (set-variable-value! var val env)
474 665c255d 2023-08-04 jrmu (define (env-loop env)
475 665c255d 2023-08-04 jrmu (define (scan vars vals)
476 665c255d 2023-08-04 jrmu (cond ((null? vars)
477 665c255d 2023-08-04 jrmu (env-loop (enclosing-environment env)))
478 665c255d 2023-08-04 jrmu ((eq? var (car vars))
479 665c255d 2023-08-04 jrmu (set-car! vals val))
480 665c255d 2023-08-04 jrmu (else (scan (cdr vars) (cdr vals)))))
481 665c255d 2023-08-04 jrmu (if (eq? env the-empty-environment)
482 665c255d 2023-08-04 jrmu (error "Unbound variable -- SET!" var)
483 665c255d 2023-08-04 jrmu (let ((frame (first-frame env)))
484 665c255d 2023-08-04 jrmu (scan (frame-variables frame)
485 665c255d 2023-08-04 jrmu (frame-values frame)))))
486 665c255d 2023-08-04 jrmu (env-loop env))
487 665c255d 2023-08-04 jrmu (define (define-variable! var val env)
488 665c255d 2023-08-04 jrmu (let ((frame (first-frame env)))
489 665c255d 2023-08-04 jrmu (define (scan vars vals)
490 665c255d 2023-08-04 jrmu (cond ((null? vars)
491 665c255d 2023-08-04 jrmu (add-binding-to-frame! var val frame))
492 665c255d 2023-08-04 jrmu ((eq? var (car vars))
493 665c255d 2023-08-04 jrmu (set-car! vals val))
494 665c255d 2023-08-04 jrmu (else (scan (cdr vars) (cdr vals)))))
495 665c255d 2023-08-04 jrmu (scan (frame-variables frame)
496 665c255d 2023-08-04 jrmu (frame-values frame))))
498 665c255d 2023-08-04 jrmu ;; (define (remove-binding-from-frame! var frame)
499 665c255d 2023-08-04 jrmu ;; (define (scan vars vals)
500 665c255d 2023-08-04 jrmu ;; (cond ((null? (cdr vars))
501 665c255d 2023-08-04 jrmu ;; (error "Binding not found -- REMOVE-BINDING-FROM-FRAME!" var))
502 665c255d 2023-08-04 jrmu ;; ((eq? var (cadr vars))
503 665c255d 2023-08-04 jrmu ;; (set-cdr! vars (cddr vars))
504 665c255d 2023-08-04 jrmu ;; (set-cdr! vals (cddr vals)))
505 665c255d 2023-08-04 jrmu ;; (else (scan (cdr vars) (cdr vals)))))
506 665c255d 2023-08-04 jrmu ;; (let ((vars (frame-variables frame))
507 665c255d 2023-08-04 jrmu ;; (vals (frame-values frame)))
508 665c255d 2023-08-04 jrmu ;; (if (eq? var (car vars))
509 665c255d 2023-08-04 jrmu ;; (begin (set-car! frame (cdr vars))
510 665c255d 2023-08-04 jrmu ;; (set-cdr! frame (cdr vals)))
511 665c255d 2023-08-04 jrmu ;; (scan vars vals))))
513 665c255d 2023-08-04 jrmu ;; primitives
514 665c255d 2023-08-04 jrmu (define (primitive-procedure? proc)
515 665c255d 2023-08-04 jrmu (tagged-list? proc 'primitive))
516 665c255d 2023-08-04 jrmu (define (primitive-implementation proc) (cadr proc))
517 665c255d 2023-08-04 jrmu (define primitive-procedures
518 665c255d 2023-08-04 jrmu (list (list 'car car)
519 665c255d 2023-08-04 jrmu (list 'cdr cdr)
520 665c255d 2023-08-04 jrmu (list 'caar caar)
521 665c255d 2023-08-04 jrmu (list 'cadr cadr)
522 665c255d 2023-08-04 jrmu (list 'cddr cddr)
523 665c255d 2023-08-04 jrmu (list 'cons cons)
524 665c255d 2023-08-04 jrmu (list 'null? null?)
525 665c255d 2023-08-04 jrmu (list '* *)
526 665c255d 2023-08-04 jrmu (list '/ /)
527 665c255d 2023-08-04 jrmu (list '+ +)
528 665c255d 2023-08-04 jrmu (list '- -)
529 665c255d 2023-08-04 jrmu (list '= =)
530 665c255d 2023-08-04 jrmu (list '< <)
531 665c255d 2023-08-04 jrmu (list '> >)
532 665c255d 2023-08-04 jrmu (list '<= <=)
533 665c255d 2023-08-04 jrmu (list '>= >=)
534 665c255d 2023-08-04 jrmu (list 'remainder remainder)
535 665c255d 2023-08-04 jrmu (list 'eq? eq?)
536 665c255d 2023-08-04 jrmu (list 'equal? equal?)
537 665c255d 2023-08-04 jrmu (list 'display display)))
538 665c255d 2023-08-04 jrmu (define (primitive-procedure-names)
540 665c255d 2023-08-04 jrmu primitive-procedures))
541 665c255d 2023-08-04 jrmu (define (primitive-procedure-objects)
542 665c255d 2023-08-04 jrmu (map (lambda (proc) (list 'primitive (cadr proc)))
543 665c255d 2023-08-04 jrmu primitive-procedures))
544 665c255d 2023-08-04 jrmu (define (apply-primitive-procedure proc args)
546 665c255d 2023-08-04 jrmu (primitive-implementation proc) args))
548 665c255d 2023-08-04 jrmu ;; execute application
550 665c255d 2023-08-04 jrmu (define (execute-application proc args succeed fail)
551 665c255d 2023-08-04 jrmu (cond ((primitive-procedure? proc)
552 665c255d 2023-08-04 jrmu (succeed (apply-primitive-procedure proc args)
554 665c255d 2023-08-04 jrmu ((compound-procedure? proc)
555 665c255d 2023-08-04 jrmu ((procedure-body proc)
556 665c255d 2023-08-04 jrmu (extend-environment (procedure-parameters proc)
558 665c255d 2023-08-04 jrmu (procedure-environment proc))
563 665c255d 2023-08-04 jrmu "Unknown procedure type -- EXECUTE-APPLICATION"
567 665c255d 2023-08-04 jrmu ;; driver-loop
568 665c255d 2023-08-04 jrmu (define (prompt-for-input string)
569 665c255d 2023-08-04 jrmu (newline) (newline) (display string) (newline))
570 665c255d 2023-08-04 jrmu (define (announce-output string)
571 665c255d 2023-08-04 jrmu (newline) (display string) (newline))
572 665c255d 2023-08-04 jrmu (define (user-print object)
573 665c255d 2023-08-04 jrmu (if (compound-procedure? object)
574 665c255d 2023-08-04 jrmu (display (list 'compound-procedure
575 665c255d 2023-08-04 jrmu (procedure-parameters object)
576 665c255d 2023-08-04 jrmu (procedure-body object)
577 665c255d 2023-08-04 jrmu '<procedure-env>))
578 665c255d 2023-08-04 jrmu (display object)))
579 665c255d 2023-08-04 jrmu (define (setup-environment)
580 665c255d 2023-08-04 jrmu (let ((initial-env
581 665c255d 2023-08-04 jrmu (extend-environment (primitive-procedure-names)
582 665c255d 2023-08-04 jrmu (primitive-procedure-objects)
583 665c255d 2023-08-04 jrmu the-empty-environment)))
584 665c255d 2023-08-04 jrmu (define-variable! 'true true initial-env)
585 665c255d 2023-08-04 jrmu (define-variable! 'false false initial-env)
586 665c255d 2023-08-04 jrmu initial-env))
587 665c255d 2023-08-04 jrmu (define the-global-environment (setup-environment))
589 665c255d 2023-08-04 jrmu (define input-prompt ";;; Amb-Eval input:")
590 665c255d 2023-08-04 jrmu (define output-prompt ";;; Amb-Eval value:")
591 665c255d 2023-08-04 jrmu (define (driver-loop)
592 665c255d 2023-08-04 jrmu (define (internal-loop try-again)
593 665c255d 2023-08-04 jrmu (prompt-for-input input-prompt)
594 665c255d 2023-08-04 jrmu (let ((input (read)))
595 665c255d 2023-08-04 jrmu (if (eq? input 'try-again)
596 665c255d 2023-08-04 jrmu (try-again)
599 665c255d 2023-08-04 jrmu (display ";;; Starting a new problem ")
600 665c255d 2023-08-04 jrmu (ambeval input
601 665c255d 2023-08-04 jrmu the-global-environment
602 665c255d 2023-08-04 jrmu ;; ambeval success
603 665c255d 2023-08-04 jrmu (lambda (val next-alternative)
604 665c255d 2023-08-04 jrmu (announce-output output-prompt)
605 665c255d 2023-08-04 jrmu (user-print val)
606 665c255d 2023-08-04 jrmu (internal-loop next-alternative))
607 665c255d 2023-08-04 jrmu ;; ambeval failure
609 665c255d 2023-08-04 jrmu (announce-output
610 665c255d 2023-08-04 jrmu ";;; There are no more values of")
611 665c255d 2023-08-04 jrmu (user-print input)
612 665c255d 2023-08-04 jrmu (driver-loop)))))))
613 665c255d 2023-08-04 jrmu (internal-loop
616 665c255d 2023-08-04 jrmu (display ";;; There is no current problem")
617 665c255d 2023-08-04 jrmu (driver-loop))))
620 665c255d 2023-08-04 jrmu ;; auxiliary
621 665c255d 2023-08-04 jrmu (define (test-case actual expected)
623 665c255d 2023-08-04 jrmu (display "Actual: ")
624 665c255d 2023-08-04 jrmu (display actual)
626 665c255d 2023-08-04 jrmu (display "Expected: ")
627 665c255d 2023-08-04 jrmu (display expected)
629 665c255d 2023-08-04 jrmu (define try-again
631 665c255d 2023-08-04 jrmu "No current problem"))
632 665c255d 2023-08-04 jrmu (define (geval exp) ;; eval globally
633 665c255d 2023-08-04 jrmu (if (eq? exp 'try-again)
634 665c255d 2023-08-04 jrmu (try-again)
635 665c255d 2023-08-04 jrmu (ambeval exp
636 665c255d 2023-08-04 jrmu the-global-environment
637 665c255d 2023-08-04 jrmu (lambda (val next-alternative)
638 665c255d 2023-08-04 jrmu (set! try-again next-alternative)
641 665c255d 2023-08-04 jrmu (set! try-again
643 665c255d 2023-08-04 jrmu "No current problem"))
644 665c255d 2023-08-04 jrmu "No alternatives"))))
645 665c255d 2023-08-04 jrmu (define (test-eval exp expected)
646 665c255d 2023-08-04 jrmu (test-case (geval exp) expected))
649 665c255d 2023-08-04 jrmu ;; test-suite
651 665c255d 2023-08-04 jrmu ;; procedure definitions
654 665c255d 2023-08-04 jrmu '(define (assoc key records)
655 665c255d 2023-08-04 jrmu (cond ((null? records) false)
656 665c255d 2023-08-04 jrmu ((equal? key (caar records)) (car records))
657 665c255d 2023-08-04 jrmu (else (assoc key (cdr records))))))
660 665c255d 2023-08-04 jrmu '(define (map proc list)
661 665c255d 2023-08-04 jrmu (if (null? list)
663 665c255d 2023-08-04 jrmu (cons (proc (car list))
664 665c255d 2023-08-04 jrmu (map proc (cdr list))))))
667 665c255d 2023-08-04 jrmu '(define (accumulate op initial sequence)
668 665c255d 2023-08-04 jrmu (if (null? sequence)
670 665c255d 2023-08-04 jrmu (op (car sequence)
671 665c255d 2023-08-04 jrmu (accumulate op initial (cdr sequence))))))
673 665c255d 2023-08-04 jrmu ;; ;; all special forms
674 665c255d 2023-08-04 jrmu (test-eval '(begin 5 6) 6)
675 665c255d 2023-08-04 jrmu (test-eval '10 10)
676 665c255d 2023-08-04 jrmu (geval '(define x 3))
677 665c255d 2023-08-04 jrmu (test-eval 'x 3)
678 665c255d 2023-08-04 jrmu (test-eval '(set! x -25) 'ok)
679 665c255d 2023-08-04 jrmu (test-eval 'x -25)
680 665c255d 2023-08-04 jrmu (geval '(define z (lambda (x y) (+ x (* x y)))))
681 665c255d 2023-08-04 jrmu (test-eval '(z 3 4) 15)
682 665c255d 2023-08-04 jrmu (test-eval '(cond ((= x -2) 'x=-2)
683 665c255d 2023-08-04 jrmu ((= x -25) 'x=-25)
684 665c255d 2023-08-04 jrmu (else 'failed))
686 665c255d 2023-08-04 jrmu (test-eval '(if true false true) false)
689 665c255d 2023-08-04 jrmu '(let ((x 4) (y 7))
690 665c255d 2023-08-04 jrmu (+ x y (* x y)))
691 665c255d 2023-08-04 jrmu (+ 4 7 (* 4 7)))
695 665c255d 2023-08-04 jrmu (geval '(define x (+ 3 8)))
696 665c255d 2023-08-04 jrmu (test-eval '(and 0 true x) 11)
697 665c255d 2023-08-04 jrmu (test-eval '(and 0 true x false) false)
698 665c255d 2023-08-04 jrmu (test-eval '(and 0 true x (set! x -2) false) false)
699 665c255d 2023-08-04 jrmu (test-eval 'x -2)
700 665c255d 2023-08-04 jrmu (test-eval '(and 0 true x false (set! x -5)) false)
701 665c255d 2023-08-04 jrmu (test-eval 'x -2)
702 665c255d 2023-08-04 jrmu (test-eval '(or false (set! x 25)) 'ok)
703 665c255d 2023-08-04 jrmu (test-eval 'x 25)
704 665c255d 2023-08-04 jrmu (test-eval '(or (set! x 2) (set! x 4)) 'ok)
705 665c255d 2023-08-04 jrmu (test-eval 'x 2)
706 665c255d 2023-08-04 jrmu (test-eval '(or false (set! x 25) true false) 'ok)
707 665c255d 2023-08-04 jrmu (test-eval 'x 25)
708 665c255d 2023-08-04 jrmu (test-eval '(or ((lambda (x) x) 5)) 5)
709 665c255d 2023-08-04 jrmu (test-eval '(or (begin (set! x (+ x 1)) x)) 26) ;; this fails because or->if repeats the same clause twice
711 665c255d 2023-08-04 jrmu (display "Failure expected")
717 665c255d 2023-08-04 jrmu '(cond ((assoc 'b '((a 1) (b 2))) => cadr)
718 665c255d 2023-08-04 jrmu (else false))
722 665c255d 2023-08-04 jrmu '(cond ((= 3 4) 'not-true)
723 665c255d 2023-08-04 jrmu ((= (* 2 4) 3) 'also-false)
724 665c255d 2023-08-04 jrmu ((map (lambda (x)
725 665c255d 2023-08-04 jrmu (* x (+ x 1)))
726 665c255d 2023-08-04 jrmu '(2 4 1 9))
728 665c255d 2023-08-04 jrmu (lambda (x)
729 665c255d 2023-08-04 jrmu (accumulate + 0 x)))
730 665c255d 2023-08-04 jrmu (else 'never-reach))
732 665c255d 2023-08-04 jrmu ;; '(6 20 2 90)
735 665c255d 2023-08-04 jrmu ;; procedure definition and application
737 665c255d 2023-08-04 jrmu '(define (factorial n)
738 665c255d 2023-08-04 jrmu (if (= n 0)
740 665c255d 2023-08-04 jrmu (* n (factorial (- n 1))))))
741 665c255d 2023-08-04 jrmu (test-eval '(factorial 5) 120)
746 665c255d 2023-08-04 jrmu '(map (lambda (x)
747 665c255d 2023-08-04 jrmu (* x (+ x 1)))
748 665c255d 2023-08-04 jrmu '(2 1 4 2 8 3))
749 665c255d 2023-08-04 jrmu '(6 2 20 6 72 12))
750 665c255d 2023-08-04 jrmu ;; accumulate
753 665c255d 2023-08-04 jrmu '(accumulate + 0 '(1 2 3 4 5))
756 665c255d 2023-08-04 jrmu ;; make-let
758 665c255d 2023-08-04 jrmu (make-let '(x y) '(3 5) '((+ x y)))
765 665c255d 2023-08-04 jrmu '(let ((x 3))
769 665c255d 2023-08-04 jrmu '(let ((x 3)
774 665c255d 2023-08-04 jrmu '(let ((x 3)
776 665c255d 2023-08-04 jrmu (+ (let ((x (+ y 2))
780 665c255d 2023-08-04 jrmu (+ (* 4 3) 3 2))
782 665c255d 2023-08-04 jrmu '(let ((x 6)
783 665c255d 2023-08-04 jrmu (y (let ((x 2))
785 665c255d 2023-08-04 jrmu (z (let ((a (* 3 2)))
794 665c255d 2023-08-04 jrmu '(let* ((x 3)
795 665c255d 2023-08-04 jrmu (y (+ x 2))
796 665c255d 2023-08-04 jrmu (z (+ x y 5)))
805 665c255d 2023-08-04 jrmu '(let* ((x 3))
806 665c255d 2023-08-04 jrmu (let* ((y 5))
811 665c255d 2023-08-04 jrmu '(let* ((x 3)
812 665c255d 2023-08-04 jrmu (y (+ x 1)))
813 665c255d 2023-08-04 jrmu (+ (let* ((x (+ y 2))
817 665c255d 2023-08-04 jrmu (+ (* 6 6) 3 4))
819 665c255d 2023-08-04 jrmu '(let* ((x 6)
820 665c255d 2023-08-04 jrmu (y (let* ((x 2)
821 665c255d 2023-08-04 jrmu (a (let* ((x (* 3 x)))
824 665c255d 2023-08-04 jrmu (z (+ x y)))
828 665c255d 2023-08-04 jrmu ;; named-let
831 665c255d 2023-08-04 jrmu '(let eight ()
837 665c255d 2023-08-04 jrmu '(let loop ((count 0))
838 665c255d 2023-08-04 jrmu (if (= 100 count)
840 665c255d 2023-08-04 jrmu (loop (+ count 1))))
843 665c255d 2023-08-04 jrmu '(define (prime? x)
844 665c255d 2023-08-04 jrmu (let prime-iter ((i 2))
845 665c255d 2023-08-04 jrmu (cond ((> (* i i) x) true)
846 665c255d 2023-08-04 jrmu ((= (remainder x i) 0) false)
847 665c255d 2023-08-04 jrmu (else (prime-iter (+ i 1)))))))
849 665c255d 2023-08-04 jrmu '(let primes ((x 2)
851 665c255d 2023-08-04 jrmu (cond ((= n 0) '())
852 665c255d 2023-08-04 jrmu ((prime? x)
854 665c255d 2023-08-04 jrmu (primes (+ x 1) (- n 1))))
855 665c255d 2023-08-04 jrmu (else (primes (+ x 1) n))))
856 665c255d 2023-08-04 jrmu '(2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59 61 67 71))
859 665c255d 2023-08-04 jrmu '(define (fib n)
860 665c255d 2023-08-04 jrmu (let fib-iter ((a 1)
863 665c255d 2023-08-04 jrmu (if (= count 0)
865 665c255d 2023-08-04 jrmu (fib-iter (+ a b) a (- count 1))))))
866 665c255d 2023-08-04 jrmu (test-eval '(fib 19) 4181)
870 665c255d 2023-08-04 jrmu '(let ((y 0))
871 665c255d 2023-08-04 jrmu (do ((x 0 (+ x 1)))
872 665c255d 2023-08-04 jrmu ((= x 5) y)
873 665c255d 2023-08-04 jrmu (set! y (+ y 1))))
884 665c255d 2023-08-04 jrmu '(let ((y 0))
886 665c255d 2023-08-04 jrmu ((= y 5) y)
887 665c255d 2023-08-04 jrmu (set! y (+ y 1))))
891 665c255d 2023-08-04 jrmu '(do ((y '(1 2 3 4)))
892 665c255d 2023-08-04 jrmu ((null? y))
893 665c255d 2023-08-04 jrmu (set! y (cdr y)))
896 665c255d 2023-08-04 jrmu '(let ((y 0))
897 665c255d 2023-08-04 jrmu (do ((x 0 (+ x 1)))
898 665c255d 2023-08-04 jrmu ((= x 5) y)
899 665c255d 2023-08-04 jrmu (set! y (+ y 1))))
902 665c255d 2023-08-04 jrmu '(let ((x '(1 3 5 7 9)))
903 665c255d 2023-08-04 jrmu (do ((x x (cdr x))
904 665c255d 2023-08-04 jrmu (sum 0 (+ sum (car x))))
905 665c255d 2023-08-04 jrmu ((null? x) sum)))
908 665c255d 2023-08-04 jrmu '(let ((z '()))
909 665c255d 2023-08-04 jrmu (do ((x '(1 2 3 4) (cdr x))
910 665c255d 2023-08-04 jrmu (y '(1 2 3 4 5 6 7 8) (cddr y)))
911 665c255d 2023-08-04 jrmu ((null? x) y x z)
912 665c255d 2023-08-04 jrmu (set! z (cons (car x) z))))
913 665c255d 2023-08-04 jrmu '(4 3 2 1))
917 665c255d 2023-08-04 jrmu ;; make-unbound!
918 665c255d 2023-08-04 jrmu ;; broken now due to scan-out-defines
920 665c255d 2023-08-04 jrmu ;; (test-eval
921 665c255d 2023-08-04 jrmu ;; '(let ((x 3))
922 665c255d 2023-08-04 jrmu ;; (let ((x 5))
923 665c255d 2023-08-04 jrmu ;; (make-unbound! x)
924 665c255d 2023-08-04 jrmu ;; (* x x)))
927 665c255d 2023-08-04 jrmu ;; (test-eval
928 665c255d 2023-08-04 jrmu ;; '(let ((x 3))
929 665c255d 2023-08-04 jrmu ;; (let ((x 5))
930 665c255d 2023-08-04 jrmu ;; (define y x)
931 665c255d 2023-08-04 jrmu ;; (make-unbound! x)
932 665c255d 2023-08-04 jrmu ;; (* y x)))
935 665c255d 2023-08-04 jrmu ;; (test-eval
936 665c255d 2023-08-04 jrmu ;; '(let ((y -1) (x 3))
937 665c255d 2023-08-04 jrmu ;; (let ((y 0.5) (x 5))
938 665c255d 2023-08-04 jrmu ;; (define a x)
939 665c255d 2023-08-04 jrmu ;; (define b y)
940 665c255d 2023-08-04 jrmu ;; (make-unbound! x)
941 665c255d 2023-08-04 jrmu ;; (make-unbound! y)
942 665c255d 2023-08-04 jrmu ;; (* a b x y)))
943 665c255d 2023-08-04 jrmu ;; (* 5 3 -1 0.5))
945 665c255d 2023-08-04 jrmu ;; (test-eval
946 665c255d 2023-08-04 jrmu ;; '(let ((x 3) (y 4))
947 665c255d 2023-08-04 jrmu ;; (let ((x 5))
948 665c255d 2023-08-04 jrmu ;; (make-unbound! x)
949 665c255d 2023-08-04 jrmu ;; (+ x 4)))
952 665c255d 2023-08-04 jrmu ;; (test-eval
953 665c255d 2023-08-04 jrmu ;; '(let ((a 1) (b 2) (c 3) (d 4))
954 665c255d 2023-08-04 jrmu ;; (make-unbound! b)
955 665c255d 2023-08-04 jrmu ;; (+ a c d))
956 665c255d 2023-08-04 jrmu ;; (+ 1 3 4))
958 665c255d 2023-08-04 jrmu ;; (test-eval
959 665c255d 2023-08-04 jrmu ;; '(let ((x 4) (y 5))
960 665c255d 2023-08-04 jrmu ;; (let ((a 1) (b 2) (c 3))
961 665c255d 2023-08-04 jrmu ;; (let ((x (+ a b)) (y (+ c a)))
962 665c255d 2023-08-04 jrmu ;; (make-unbound! x)
963 665c255d 2023-08-04 jrmu ;; (let ((a x) (b (+ x y)))
964 665c255d 2023-08-04 jrmu ;; (define z b)
965 665c255d 2023-08-04 jrmu ;; (make-unbound! b)
966 665c255d 2023-08-04 jrmu ;; (* (+ a z)
967 665c255d 2023-08-04 jrmu ;; (+ a b y))))))
968 665c255d 2023-08-04 jrmu ;; (* (+ 4 8)
969 665c255d 2023-08-04 jrmu ;; (+ 4 2 4)))
971 665c255d 2023-08-04 jrmu ;; x 3 -- y 4
972 665c255d 2023-08-04 jrmu ;; x 4 -- y 4
973 665c255d 2023-08-04 jrmu ;; a 4 -- b 4
974 665c255d 2023-08-04 jrmu ;; a 4 -- b 2
976 665c255d 2023-08-04 jrmu ;; scan-out-defines
979 665c255d 2023-08-04 jrmu '(define (f x)
980 665c255d 2023-08-04 jrmu (define (even? n)
981 665c255d 2023-08-04 jrmu (if (= n 0)
983 665c255d 2023-08-04 jrmu (odd? (- n 1))))
984 665c255d 2023-08-04 jrmu (define (odd? n)
985 665c255d 2023-08-04 jrmu (if (= n 0)
987 665c255d 2023-08-04 jrmu (even? (- n 1))))
988 665c255d 2023-08-04 jrmu (even? x)))
989 665c255d 2023-08-04 jrmu (test-eval '(f 5) false)
990 665c255d 2023-08-04 jrmu (test-eval '(f 10) true)
992 665c255d 2023-08-04 jrmu ;; ;; (geval
993 665c255d 2023-08-04 jrmu ;; ;; '(let ((x 5))
994 665c255d 2023-08-04 jrmu ;; ;; (define y x)
995 665c255d 2023-08-04 jrmu ;; ;; (define x 3)
996 665c255d 2023-08-04 jrmu ;; ;; (+ x y)))
997 665c255d 2023-08-04 jrmu ;; ;; signal an error because x is undefined if variables are scanned out
999 665c255d 2023-08-04 jrmu ;; ;; letrec
1002 665c255d 2023-08-04 jrmu ;; '(define (f x)
1003 665c255d 2023-08-04 jrmu ;; (letrec ((even?
1004 665c255d 2023-08-04 jrmu ;; (lambda (n)
1005 665c255d 2023-08-04 jrmu ;; (if (= n 0)
1007 665c255d 2023-08-04 jrmu ;; (odd? (- n 1)))))
1009 665c255d 2023-08-04 jrmu ;; (lambda (n)
1010 665c255d 2023-08-04 jrmu ;; (if (= n 0)
1012 665c255d 2023-08-04 jrmu ;; (even? (- n 1))))))
1013 665c255d 2023-08-04 jrmu ;; (even? x))))
1014 665c255d 2023-08-04 jrmu ;; (test-eval '(f 11) false)
1015 665c255d 2023-08-04 jrmu ;; (test-eval '(f 16) true)
1017 665c255d 2023-08-04 jrmu ;; (test-eval
1018 665c255d 2023-08-04 jrmu ;; '(letrec ((fact
1019 665c255d 2023-08-04 jrmu ;; (lambda (n)
1020 665c255d 2023-08-04 jrmu ;; (if (= n 1)
1022 665c255d 2023-08-04 jrmu ;; (* n (fact (- n 1)))))))
1023 665c255d 2023-08-04 jrmu ;; (fact 10))
1024 665c255d 2023-08-04 jrmu ;; 3628800)
1027 665c255d 2023-08-04 jrmu (test-eval '(amb 1 2 3) 1)
1028 665c255d 2023-08-04 jrmu (test-eval 'try-again 2)
1029 665c255d 2023-08-04 jrmu (test-eval 'try-again 3)
1030 665c255d 2023-08-04 jrmu (test-eval 'try-again "No alternatives")
1031 665c255d 2023-08-04 jrmu (test-eval 'try-again "No current problem")
1032 665c255d 2023-08-04 jrmu (test-eval 'try-again "No current problem")
1033 665c255d 2023-08-04 jrmu (test-eval '(amb (amb 1 2) (amb 'a 'b))
1035 665c255d 2023-08-04 jrmu (test-eval 'try-again 2)
1036 665c255d 2023-08-04 jrmu (test-eval 'try-again 'a)
1037 665c255d 2023-08-04 jrmu (test-eval 'try-again 'b)
1038 665c255d 2023-08-04 jrmu (test-eval 'try-again "No alternatives")
