Scheme - 積極制御評価機(エラーの捕捉(基本手続きの作用で生じるエラーの取り扱い(car, 除算(/))))

計算機プログラムの構造と解釈
Gerald Jay Sussman, Julie Sussman
Harold Abelson (原著) 和田 英一 (翻訳)

開発環境

• OS X Mavericks - Apple(OS)
• Emacs (CUI)、BBEdit - Bare Bones Software, Inc. (GUI) (Text Editor)
• Scheme (プログラミング言語)
• MIT/GNU Scheme (処理系)

計算機プログラムの構造と解釈(Gerald Jay Sussman(原著)、Julie Sussman(原著)、Harold Abelson(原著)、和田 英一(翻訳)、ピアソンエデュケーション、原書: Structure and Interpretation of Computer Programs (MIT Electrical Engineering and Computer Science)(SICP))の5(レジスタ計算機での計算)、5.4(積極制御評価機)、5.4.4(評価の実行)、評価器の性能監視、問題 5.30-b.を解いてみる。

その他参考書籍

• Instructor's Manual to Accompany Structure & Interpretation of Computer Programs

問題 5.30-b.

修正、追加箇所。

コード(BBEdit)

eval.scm

;;
(define (apply-primitive-procedure proc args)
  (let ((p (primitive-implementation proc)))
    (cond ((and (eq? p car) (not (pair? (car args))))
           'apply-primitive-procedure-error)
          ((and (eq? p /) (eq? (cadr args) 0))
           'apply-primitive-procedure-error)
          (else
           (my-apply p args)))))

(define (apply-primitive-procedure-error? val)
  (eq? val 'apply-primitive-procedure-error))
;;

コード(BBEdit)

eceval.scm

;;
   (list 'apply-primitive-procedure-error? apply-primitive-procedure-error?)
;;
primitive-apply
  (assign val (op apply-primitive-procedure)
              (reg proc)
              (reg argl))
  (test (op apply-primitive-procedure-error?) (reg val))
  (branch (label primitive-apply-error))
  (restore continue)
  (goto (reg continue))
primitive-apply-error
  (assign val (const primitive-apply-error))
  (goto (label signal-error))
;;

コード(BBEdit)

sample.scm

(load "./eval.scm")
(load "./register.scm")
(load "./eceval.scm")
(start eceval)

入出力結果(Terminal, REPL(Read, Eval, Print, Loop))

$ scheme
MIT/GNU Scheme running under MacOSX
Type `^C' (control-C) followed by `H' to obtain information about interrupts.

Copyright (C) 2011 Massachusetts Institute of Technology
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Image saved on Saturday October 26, 2013 at 11:02:50 PM
  Release 9.1.1 || Microcode 15.3 || Runtime 15.7 || SF 4.41 || LIAR/C 4.118
  Edwin 3.116

1 ]=> (load "./sample.scm")

;Loading "./sample.scm"...
;  Loading "eval.scm"... done
;  Loading "register.scm"...
;  Loading "eceval.scm"... done


;;; EC-Eval input:
(/ 10 5)

(total-pushes = 8 maximum-depth = 5)
;;; EC-Eval value:
2

;;; EC-Eval input:
(/ 10 0)
primitive-apply-error

;;; EC-Eval input:
(car '(1 2))

(total-pushes = 5 maximum-depth = 3)
;;; EC-Eval value:
1

;;; EC-Eval input:
(car 1)
primitive-apply-error

;;; EC-Eval input:
End of input stream reached.
Moriturus te saluto.
$