Install explicit-control evaluator
parent
c421911b3a
commit
6cfaff4c07
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@ -1,5 +1,17 @@
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(load "util.scm")
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(load "misc/sicp-regsim.scm")
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(load "misc/sicp-eceval.scm")
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(display "\nex-5.23\n")
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(define the-global-environment (setup-environment))
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(set-register-contents! eceval 'exp '(+ 1 2))
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(start eceval)
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(assert (get-register-contents eceval 'val) 3)
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(display "\nex-5.23 - derived-expressions\n")
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(display "\nex-5.24\n")
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;(display "\nex-5.25\n")
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@ -0,0 +1,188 @@
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;;;;SIMULATION OF ECEVAL MACHINE OPERATIONS --
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;;;;loaded by load-eceval.scm and by load-eceval-compiler.scm
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;;;;FIRST A LOT FROM 4.1.2-4.1.4
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;(load "ch5-syntax.scm"); ;section 4.1.2 syntax procedures
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(load "misc/sicp-eceval-syntax.scm") ;section 4.1.2 syntax procedures
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;;;SECTION 4.1.3
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;;; operations used by compiled code and eceval except as noted
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(define (true? x)
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(not (eq? x false)))
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;;* not used by eceval itself -- used by compiled code when that
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;; is run in the eceval machine
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(define (false? x)
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(eq? x false))
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;;following compound-procedure operations not used by compiled code
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(define (make-procedure parameters body env)
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(list 'procedure parameters body env))
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(define (compound-procedure? p)
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(tagged-list? p 'procedure))
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(define (procedure-parameters p) (cadr p))
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(define (procedure-body p) (caddr p))
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(define (procedure-environment p) (cadddr p))
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;;(end of compound procedures)
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(define (enclosing-environment env) (cdr env))
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(define (first-frame env) (car env))
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(define the-empty-environment '())
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(define (make-frame variables values)
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(cons variables values))
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(define (frame-variables frame) (car frame))
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(define (frame-values frame) (cdr frame))
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(define (add-binding-to-frame! var val frame)
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(set-car! frame (cons var (car frame)))
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(set-cdr! frame (cons val (cdr frame))))
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(define (extend-environment vars vals base-env)
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(if (= (length vars) (length vals))
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(cons (make-frame vars vals) base-env)
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(if (< (length vars) (length vals))
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(error "Too many arguments supplied" vars vals)
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(error "Too few arguments supplied" vars vals))))
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(define (lookup-variable-value var env)
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(define (env-loop env)
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(define (scan vars vals)
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(cond ((null? vars)
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(env-loop (enclosing-environment env)))
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((eq? var (car vars))
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(car vals))
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(else (scan (cdr vars) (cdr vals)))))
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(if (eq? env the-empty-environment)
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(error "Unbound variable" var)
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(let ((frame (first-frame env)))
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(scan (frame-variables frame)
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(frame-values frame)))))
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(env-loop env))
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(define (set-variable-value! var val env)
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(define (env-loop env)
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(define (scan vars vals)
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(cond ((null? vars)
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(env-loop (enclosing-environment env)))
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((eq? var (car vars))
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(set-car! vals val))
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(else (scan (cdr vars) (cdr vals)))))
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(if (eq? env the-empty-environment)
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(error "Unbound variable -- SET!" var)
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(let ((frame (first-frame env)))
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(scan (frame-variables frame)
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(frame-values frame)))))
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(env-loop env))
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(define (define-variable! var val env)
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(let ((frame (first-frame env)))
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(define (scan vars vals)
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(cond ((null? vars)
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(add-binding-to-frame! var val frame))
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((eq? var (car vars))
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(set-car! vals val))
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(else (scan (cdr vars) (cdr vals)))))
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(scan (frame-variables frame)
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(frame-values frame))))
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;;;SECTION 4.1.4
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(define (setup-environment)
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(let ((initial-env
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(extend-environment (primitive-procedure-names)
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(primitive-procedure-objects)
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the-empty-environment)))
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(define-variable! 'true true initial-env)
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(define-variable! 'false false initial-env)
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initial-env))
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(define (primitive-procedure? proc)
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(tagged-list? proc 'primitive))
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(define (primitive-implementation proc) (cadr proc))
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(define primitive-procedures
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(list (list 'car car)
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(list 'cdr cdr)
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(list 'cons cons)
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(list 'null? null?)
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;;above from book -- here are some more
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(list '+ +)
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(list '- -)
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(list '* *)
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(list '= =)
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(list '/ /)
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(list '> >)
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(list '< <)
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))
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(define (primitive-procedure-names)
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(map car
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primitive-procedures))
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(define (primitive-procedure-objects)
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(map (lambda (proc) (list 'primitive (cadr proc)))
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primitive-procedures))
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(define apply-in-underlying-scheme apply)
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(define (apply-primitive-procedure proc args)
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(apply-in-underlying-scheme
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(primitive-implementation proc) args))
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(define (prompt-for-input string)
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(newline) (newline) (display string) (newline))
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(define (announce-output string)
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(newline) (display string) (newline))
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(define (user-print object)
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(if (compound-procedure? object)
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(display (list 'compound-procedure
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(procedure-parameters object)
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(procedure-body object)
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'<procedure-env>))
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(display object)))
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;;; Simulation of new machine operations needed by
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;;; eceval machine (not used by compiled code)
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;;; From section 5.4.1 footnote
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(define (empty-arglist) '())
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(define (adjoin-arg arg arglist)
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(append arglist (list arg)))
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(define (last-operand? ops)
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(null? (cdr ops)))
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;;; From section 5.4.2 footnote, for non-tail-recursive sequences
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(define (no-more-exps? seq) (null? seq))
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;;; From section 5.4.4 footnote
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(define (get-global-environment)
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the-global-environment)
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;; will do following when ready to run, not when load this file
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;;(define the-global-environment (setup-environment))
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;;; Simulation of new machine operations needed for compiled code
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;;; and eceval/compiler interface (not used by plain eceval machine)
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;;; From section 5.5.2 footnote
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(define (make-compiled-procedure entry env)
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(list 'compiled-procedure entry env))
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(define (compiled-procedure? proc)
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(tagged-list? proc 'compiled-procedure))
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(define (compiled-procedure-entry c-proc) (cadr c-proc))
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(define (compiled-procedure-env c-proc) (caddr c-proc))
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@ -0,0 +1,120 @@
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;;;;SCHEME SYNTAX FROM SECTION 4.1.2 OF STRUCTURE AND INTERPRETATION OF
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;;; COMPUTER PROGRAMS, TO SUPPORT CHAPTER 5
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;;;;Loaded by compiler.scm (for use by compiler), and by eceval-support.scm
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;;;; (for simulation of eceval machine operations)
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(define (self-evaluating? exp)
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(cond ((number? exp) true)
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((string? exp) true)
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(else false)))
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(define (quoted? exp)
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(tagged-list? exp 'quote))
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(define (text-of-quotation exp) (cadr exp))
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(define (tagged-list? exp tag)
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(if (pair? exp)
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(eq? (car exp) tag)
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false))
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(define (variable? exp) (symbol? exp))
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(define (assignment? exp)
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(tagged-list? exp 'set!))
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(define (assignment-variable exp) (cadr exp))
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(define (assignment-value exp) (caddr exp))
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(define (definition? exp)
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(tagged-list? exp 'define))
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(define (definition-variable exp)
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(if (symbol? (cadr exp))
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(cadr exp)
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(caadr exp)))
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(define (definition-value exp)
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(if (symbol? (cadr exp))
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(caddr exp)
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(make-lambda (cdadr exp)
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(cddr exp))))
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(define (lambda? exp) (tagged-list? exp 'lambda))
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(define (lambda-parameters exp) (cadr exp))
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(define (lambda-body exp) (cddr exp))
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(define (make-lambda parameters body)
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(cons 'lambda (cons parameters body)))
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(define (if? exp) (tagged-list? exp 'if))
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(define (if-predicate exp) (cadr exp))
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(define (if-consequent exp) (caddr exp))
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(define (if-alternative exp)
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(if (not (null? (cdddr exp)))
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(cadddr exp)
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'false))
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(define (begin? exp) (tagged-list? exp 'begin))
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(define (begin-actions exp) (cdr exp))
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(define (last-exp? seq) (null? (cdr seq)))
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(define (first-exp seq) (car seq))
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(define (rest-exps seq) (cdr seq))
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(define (application? exp) (pair? exp))
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(define (operator exp) (car exp))
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(define (operands exp) (cdr exp))
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(define (no-operands? ops) (null? ops))
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(define (first-operand ops) (car ops))
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(define (rest-operands ops) (cdr ops))
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;;;**following needed only to implement COND as derived expression,
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;;; not needed by eceval machine in text. But used by compiler
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;; from 4.1.2
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(define (make-if predicate consequent alternative)
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(list 'if predicate consequent alternative))
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(define (sequence->exp seq)
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(cond ((null? seq) seq)
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((last-exp? seq) (first-exp seq))
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(else (make-begin seq))))
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(define (make-begin seq) (cons 'begin seq))
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(define (cond? exp) (tagged-list? exp 'cond))
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(define (cond-clauses exp) (cdr exp))
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(define (cond-else-clause? clause)
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(eq? (cond-predicate clause) 'else))
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(define (cond-predicate clause) (car clause))
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(define (cond-actions clause) (cdr clause))
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(define (cond->if exp)
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(expand-clauses (cond-clauses exp)))
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(define (expand-clauses clauses)
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(if (null? clauses)
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'false ; no else clause
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(let ((first (car clauses))
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(rest (cdr clauses)))
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(if (cond-else-clause? first)
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(if (null? rest)
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(sequence->exp (cond-actions first))
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(error "ELSE clause isn't last -- COND->IF"
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clauses))
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(make-if (cond-predicate first)
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(sequence->exp (cond-actions first))
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(expand-clauses rest))))))
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;; end of Cond support
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@ -0,0 +1,289 @@
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;;;;EXPLICIT-CONTROL EVALUATOR FROM SECTION 5.4 OF
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;;;; STRUCTURE AND INTERPRETATION OF COMPUTER PROGRAMS
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;;;;Matches code in ch5.scm
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;;; To use it
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;;; -- load "load-eceval.scm", which loads this file and the
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;;; support it needs (including the register-machine simulator)
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;;; -- To initialize and start the machine, do
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;: (define the-global-environment (setup-environment))
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;: (start eceval)
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(load "misc/sicp-eceval-support.scm")
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;; To restart, can do just
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;: (start eceval)
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;;;;;;;;;;
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;;**NB. To [not] monitor stack operations, comment in/[out] the line after
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;; print-result in the machine controller below
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;;**Also choose the desired make-stack version in regsim.scm
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(define eceval-operations
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(list
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;;primitive Scheme operations
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(list 'read read)
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;;operations in syntax.scm
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(list 'self-evaluating? self-evaluating?)
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(list 'quoted? quoted?)
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(list 'text-of-quotation text-of-quotation)
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(list 'variable? variable?)
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(list 'assignment? assignment?)
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(list 'assignment-variable assignment-variable)
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(list 'assignment-value assignment-value)
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(list 'definition? definition?)
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(list 'definition-variable definition-variable)
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(list 'definition-value definition-value)
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(list 'lambda? lambda?)
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(list 'lambda-parameters lambda-parameters)
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(list 'lambda-body lambda-body)
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(list 'if? if?)
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(list 'if-predicate if-predicate)
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(list 'if-consequent if-consequent)
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(list 'if-alternative if-alternative)
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(list 'begin? begin?)
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(list 'begin-actions begin-actions)
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(list 'last-exp? last-exp?)
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(list 'first-exp first-exp)
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(list 'rest-exps rest-exps)
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(list 'application? application?)
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(list 'operator operator)
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(list 'operands operands)
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(list 'no-operands? no-operands?)
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(list 'first-operand first-operand)
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(list 'rest-operands rest-operands)
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;;operations in eceval-support.scm
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(list 'true? true?)
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(list 'make-procedure make-procedure)
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(list 'compound-procedure? compound-procedure?)
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(list 'procedure-parameters procedure-parameters)
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(list 'procedure-body procedure-body)
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(list 'procedure-environment procedure-environment)
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(list 'extend-environment extend-environment)
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(list 'lookup-variable-value lookup-variable-value)
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(list 'set-variable-value! set-variable-value!)
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(list 'define-variable! define-variable!)
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(list 'primitive-procedure? primitive-procedure?)
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(list 'apply-primitive-procedure apply-primitive-procedure)
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(list 'prompt-for-input prompt-for-input)
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(list 'announce-output announce-output)
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(list 'user-print user-print)
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(list 'empty-arglist empty-arglist)
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(list 'adjoin-arg adjoin-arg)
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(list 'last-operand? last-operand?)
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(list 'no-more-exps? no-more-exps?) ;for non-tail-recursive machine
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(list 'get-global-environment get-global-environment))
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)
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(define eceval
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(make-machine
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'(exp env val proc argl continue unev)
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eceval-operations
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'(
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(perform (op initialize-stack))
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(assign env (op get-global-environment))
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(assign continue (label ev-done))
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(goto (label eval-dispatch))
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unknown-expression-type
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(assign val (const unknown-expression-type-error))
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(goto (label signal-error))
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unknown-procedure-type
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(restore continue)
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(assign val (const unknown-procedure-type-error))
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(goto (label signal-error))
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signal-error
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(perform (op user-print) (reg val))
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(goto (label ev-done))
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;;SECTION 5.4.1
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eval-dispatch
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(test (op self-evaluating?) (reg exp))
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(branch (label ev-self-eval))
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(test (op variable?) (reg exp))
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(branch (label ev-variable))
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(test (op quoted?) (reg exp))
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(branch (label ev-quoted))
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(test (op assignment?) (reg exp))
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(branch (label ev-assignment))
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(test (op definition?) (reg exp))
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(branch (label ev-definition))
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(test (op if?) (reg exp))
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(branch (label ev-if))
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(test (op lambda?) (reg exp))
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(branch (label ev-lambda))
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(test (op begin?) (reg exp))
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(branch (label ev-begin))
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(test (op application?) (reg exp))
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(branch (label ev-application))
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(goto (label unknown-expression-type))
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ev-self-eval
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(assign val (reg exp))
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(goto (reg continue))
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ev-variable
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(assign val (op lookup-variable-value) (reg exp) (reg env))
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(goto (reg continue))
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ev-quoted
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(assign val (op text-of-quotation) (reg exp))
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(goto (reg continue))
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ev-lambda
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(assign unev (op lambda-parameters) (reg exp))
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(assign exp (op lambda-body) (reg exp))
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(assign val (op make-procedure)
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(reg unev) (reg exp) (reg env))
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(goto (reg continue))
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ev-application
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(save continue)
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(save env)
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(assign unev (op operands) (reg exp))
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(save unev)
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(assign exp (op operator) (reg exp))
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(assign continue (label ev-appl-did-operator))
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(goto (label eval-dispatch))
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ev-appl-did-operator
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(restore unev)
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(restore env)
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(assign argl (op empty-arglist))
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(assign proc (reg val))
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(test (op no-operands?) (reg unev))
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||||
(branch (label apply-dispatch))
|
||||
(save proc)
|
||||
ev-appl-operand-loop
|
||||
(save argl)
|
||||
(assign exp (op first-operand) (reg unev))
|
||||
(test (op last-operand?) (reg unev))
|
||||
(branch (label ev-appl-last-arg))
|
||||
(save env)
|
||||
(save unev)
|
||||
(assign continue (label ev-appl-accumulate-arg))
|
||||
(goto (label eval-dispatch))
|
||||
ev-appl-accumulate-arg
|
||||
(restore unev)
|
||||
(restore env)
|
||||
(restore argl)
|
||||
(assign argl (op adjoin-arg) (reg val) (reg argl))
|
||||
(assign unev (op rest-operands) (reg unev))
|
||||
(goto (label ev-appl-operand-loop))
|
||||
ev-appl-last-arg
|
||||
(assign continue (label ev-appl-accum-last-arg))
|
||||
(goto (label eval-dispatch))
|
||||
ev-appl-accum-last-arg
|
||||
(restore argl)
|
||||
(assign argl (op adjoin-arg) (reg val) (reg argl))
|
||||
(restore proc)
|
||||
(goto (label apply-dispatch))
|
||||
apply-dispatch
|
||||
(test (op primitive-procedure?) (reg proc))
|
||||
(branch (label primitive-apply))
|
||||
(test (op compound-procedure?) (reg proc))
|
||||
(branch (label compound-apply))
|
||||
(goto (label unknown-procedure-type))
|
||||
|
||||
primitive-apply
|
||||
(assign val (op apply-primitive-procedure)
|
||||
(reg proc)
|
||||
(reg argl))
|
||||
(restore continue)
|
||||
(goto (reg continue))
|
||||
|
||||
compound-apply
|
||||
(assign unev (op procedure-parameters) (reg proc))
|
||||
(assign env (op procedure-environment) (reg proc))
|
||||
(assign env (op extend-environment)
|
||||
(reg unev) (reg argl) (reg env))
|
||||
(assign unev (op procedure-body) (reg proc))
|
||||
(goto (label ev-sequence))
|
||||
|
||||
;;;SECTION 5.4.2
|
||||
ev-begin
|
||||
(assign unev (op begin-actions) (reg exp))
|
||||
(save continue)
|
||||
(goto (label ev-sequence))
|
||||
|
||||
ev-sequence
|
||||
(assign exp (op first-exp) (reg unev))
|
||||
(test (op last-exp?) (reg unev))
|
||||
(branch (label ev-sequence-last-exp))
|
||||
(save unev)
|
||||
(save env)
|
||||
(assign continue (label ev-sequence-continue))
|
||||
(goto (label eval-dispatch))
|
||||
ev-sequence-continue
|
||||
(restore env)
|
||||
(restore unev)
|
||||
(assign unev (op rest-exps) (reg unev))
|
||||
(goto (label ev-sequence))
|
||||
ev-sequence-last-exp
|
||||
(restore continue)
|
||||
(goto (label eval-dispatch))
|
||||
|
||||
;;;SECTION 5.4.3
|
||||
|
||||
ev-if
|
||||
(save exp)
|
||||
(save env)
|
||||
(save continue)
|
||||
(assign continue (label ev-if-decide))
|
||||
(assign exp (op if-predicate) (reg exp))
|
||||
(goto (label eval-dispatch))
|
||||
ev-if-decide
|
||||
(restore continue)
|
||||
(restore env)
|
||||
(restore exp)
|
||||
(test (op true?) (reg val))
|
||||
(branch (label ev-if-consequent))
|
||||
ev-if-alternative
|
||||
(assign exp (op if-alternative) (reg exp))
|
||||
(goto (label eval-dispatch))
|
||||
ev-if-consequent
|
||||
(assign exp (op if-consequent) (reg exp))
|
||||
(goto (label eval-dispatch))
|
||||
|
||||
ev-assignment
|
||||
(assign unev (op assignment-variable) (reg exp))
|
||||
(save unev)
|
||||
(assign exp (op assignment-value) (reg exp))
|
||||
(save env)
|
||||
(save continue)
|
||||
(assign continue (label ev-assignment-1))
|
||||
(goto (label eval-dispatch))
|
||||
ev-assignment-1
|
||||
(restore continue)
|
||||
(restore env)
|
||||
(restore unev)
|
||||
(perform
|
||||
(op set-variable-value!) (reg unev) (reg val) (reg env))
|
||||
(assign val (const ok))
|
||||
(goto (reg continue))
|
||||
|
||||
ev-definition
|
||||
(assign unev (op definition-variable) (reg exp))
|
||||
(save unev)
|
||||
(assign exp (op definition-value) (reg exp))
|
||||
(save env)
|
||||
(save continue)
|
||||
(assign continue (label ev-definition-1))
|
||||
(goto (label eval-dispatch))
|
||||
ev-definition-1
|
||||
(restore continue)
|
||||
(restore env)
|
||||
(restore unev)
|
||||
(perform
|
||||
(op define-variable!) (reg unev) (reg val) (reg env))
|
||||
(assign val (const ok))
|
||||
(goto (reg continue))
|
||||
ev-done
|
||||
)))
|
||||
|
||||
'(EXPLICIT CONTROL EVALUATOR LOADED)
|
||||
Loading…
Reference in New Issue