; -*- Mode: Scheme; Syntax: Scheme; Package: Scheme; -*-

; This is file stub.scm.

;;;; Data manipulation stub

; ----- DATA -----

(define (enter-fixnum x)   x)
(define (extract-fixnum x) x)
(define (enter-boolean x)  x)
(define (enter-char x)     x)
(define (extract-char x)   x)

(define false (if (eq? #f '()) (vector '<false>) #f))   ;????
(define (false? x) (or (eq? x false) (eq? x '())))
(define true #t)
(define null '())
(define unspecified  (list '<unspecified>))

(define unassigned-marker (list '<unassigned>))
(define unbound-marker    (list '<unbound>))

(define (undefined? x)
  (or (eq? x unassigned-marker)
      (eq? x unbound-marker)))

(define fixnum? integer?)

(define (available? n) n #t)   ;Used by make-rest-list code

; ----- STRUCT -----

(define (extract-string x) x)

(define (intern string symbol-table)
  symbol-table ;ignored
  (string->symbol string))

(define (reverse-list->string l len)  ;can we flush this?
  (let ((str (make-string len)))
    (do ((i (- len 1) (- i 1))
	 (l l (cdr l)))
	((< i 0) str)
      (string-set! str i (car l)))))

(define (make-port mode index id)
  mode id ;ignored
  (case index
    ((0) (current-input-port))
    ((1) (current-output-port))
    ;; Fix later
    (else (error "bogus argument to make-port" index))))

; ----- GC -----

(define *finished* (unassigned))
(define *root* (unassigned))
(define *retrying-after-gc?* #f)

(define (collect) (computed-goto *finished*))
(define (collect-and-retry) (computed-goto *finished*))

(define (initialize-heap) 'done)

(define (time-to-collect?) #f)

; ----- TRANSPORT stub -----

(define *system-environment* (unassigned))
(define *symbol-table* '<the-symbol-table>)
(define (initialize-transporter)
  (set! *system-environment* (make-empty-environment))
  'done)

(define (enter x) x)
(define (extract x) x)

; ----- RESUME stub -----

(define (initialize-memory) 'ok)