;;;"scheme48.init" Initialisation for SLIB for Scheme48	-*-scheme-*-
;;; Copyright (C) 1992, 1993, 1994, 1995, 1997 Aubrey Jaffer.
;
;Permission to copy this software, to redistribute it, and to use it
;for any purpose is granted, subject to the following restrictions and
;understandings.
;
;1.  Any copy made of this software must include this copyright notice
;in full.
;
;2.  I have made no warrantee or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3.  In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.

;;; If you know the magic incantation to make a "," command available
;;; as a scheme procedure, you can make a nifty slib function to do
;;; this (like `slib:dump' in "vscm.init").  But for now, type:
;;;	make slib48

;;; (software-type) should be set to the generic operating system type.
;;; UNIX, VMS, MACOS, AMIGA and MS-DOS are supported.

(define (software-type) 'UNIX)

;;; (scheme-implementation-type) should return the name of the scheme
;;; implementation loading this file.

(define (scheme-implementation-type) 'Scheme48)

;;; (scheme-implementation-version) should return a string describing
;;; the version of the scheme implementation loading this file.

(define scheme-implementation-version
  (cond ((= -86400 (modulo -2177452800 -86400))
	 (display "scheme48-0.36 has been superseded by")
	 (newline)
	 (display "ftp@ftp-swiss.ai.mit.edu:pub/s48/scheme48-0.46.tgz")
	 (newline)
	 (display "ftp://ftp-swiss.ai.mit.edu/pub/s48/scheme48-0.46.tgz")
	 (newline)
	 (lambda () "0.36"))
	(else (lambda () "0.46"))))

;;; (implementation-vicinity) should be defined to be the pathname of
;;; the directory where any auxiliary files to your Scheme
;;; implementation reside.

;;; [ defined from the Makefile ]

;;; (library-vicinity) should be defined to be the pathname of the
;;; directory where files of Scheme library functions reside.

;;; [ defined from the Makefile ]

(define getenv s48-getenv)
(define system s48-system)

;;; (home-vicinity) should return the vicinity of the user's HOME
;;; directory, the directory which typically contains files which
;;; customize a computer environment for a user.

(define home-vicinity
  (let ((home-path (getenv "HOME")))
    (lambda () home-path)))

;;; *FEATURES* should be set to a list of symbols describing features
;;; of this implementation.  See Template.scm for the list of feature
;;; names.

(define *features*
      '(
	source				;can load scheme source files
					;(slib:load-source "filename")
;	compiled			;can load compiled files
					;(slib:load-compiled "filename")
	rev4-report			;conforms to
	ieee-p1178			;conforms to
	rev4-optional-procedures
	multiarg/and-
	multiarg-apply
	rationalize
	delay				;has delay and force
	with-file
	char-ready?			;has
	eval				;proposed 2-argument eval
	values				;proposed multiple values
	dynamic-wind			;proposed dynamic-wind
	full-continuation		;can return multiple times
	macro				;R4RS appendix's DEFINE-SYNTAX
	system				;posix (system <string>)
	getenv				;posix (getenv <string>)
	))

;;; (OUTPUT-PORT-WIDTH <port>)
(define (output-port-width . arg) 79)

;;; (OUTPUT-PORT-HEIGHT <port>)
(define (output-port-height . arg) 24)

;;; (CURRENT-ERROR-PORT)
(define current-error-port s48-current-error-port)

;;; (TMPNAM) makes a temporary file name.
(define tmpnam
  (let ((cntr 100))
    (lambda () (set! cntr (+ 1 cntr))
	    (let ((tmp (string-append "slib_" (number->string cntr))))
	      (if (file-exists? tmp) (tmpnam) tmp)))))

;;; (FILE-EXISTS? <string>)
(define (file-exists? f)
  (call-with-current-continuation
   (lambda (k)
     (s48-with-handler
      (lambda (condition decline)
	(k #f))
      (lambda ()
	(close-input-port (open-input-file f))
	#t)))))

;;; (DELETE-FILE <string>)
(define (delete-file file-name)
  (s48-system (string-append "rm " file-name)))

;;; FORCE-OUTPUT flushes any pending output on optional arg output port
;;; use this definition if your system doesn't have such a procedure.
(define (force-output . arg)
  (s48-force-output
   (if (null? arg) (current-output-port) (car arg))))

;;; CHAR-CODE-LIMIT is one greater than the largest integer which can
;;; be returned by CHAR->INTEGER.
(define integer->char s48-ascii->char)
(define char->integer
  (let ((char->integer char->integer)
	(code0 (char->integer (integer->char 0))))
    (lambda (char) (- (char->integer char) code0))))
(define char-code-limit 256)

;;; Workaround MODULO bug
(define modulo
  (let ((modulo modulo))
    (lambda (n1 n2)
      (let ((ans (modulo n1 n2)))
	(if (= ans n2) (- ans ans) ans)))))

;;; MOST-POSITIVE-FIXNUM is used in modular.scm
(define most-positive-fixnum #x1FFFFFFF)

;;; Return argument
(define (identity x) x)

;;; SLIB:EVAL is single argument eval using the top-level (user) environment.
(define slib:eval
  (let ((eval eval)
	(interaction-environment interaction-environment))
    (lambda (form)
      (eval form (interaction-environment)))))

;;; If your implementation provides R4RS macros:
(define macro:eval slib:eval)
(define (macro:load <pathname>)
  (if (not (file-exists? <pathname>))
      (set! <pathname> (string-append <pathname> (scheme-file-suffix))))
  (load <pathname>))

(define *defmacros*
  (list (cons 'defmacro
	      (lambda (name parms . body)
		`(set! *defmacros* (cons (cons ',name (lambda ,parms ,@body))
				      *defmacros*))))))
(define (defmacro? m) (and (assq m *defmacros*) #t))

(define (macroexpand-1 e)
  (if (pair? e) (let ((a (car e)))
		  (cond ((symbol? a) (set! a (assq a *defmacros*))
				     (if a (apply (cdr a) (cdr e)) e))
			(else e)))
      e))

(define (macroexpand e)
  (if (pair? e) (let ((a (car e)))
		  (cond ((symbol? a)
			 (set! a (assq a *defmacros*))
			 (if a (macroexpand (apply (cdr a) (cdr e))) e))
			(else e)))
      e))

(define gentemp
  (let ((*gensym-counter* -1))
    (lambda ()
      (set! *gensym-counter* (+ *gensym-counter* 1))
      (string->symbol
       (string-append "slib:G" (number->string *gensym-counter*))))))

(define base:eval slib:eval)
(define (defmacro:eval x) (base:eval (defmacro:expand* x)))
(define (defmacro:expand* x)
  (require 'defmacroexpand) (apply defmacro:expand* x '()))

(define (defmacro:load <pathname>)
  (slib:eval-load <pathname> defmacro:eval))

(define (slib:eval-load <pathname> evl)
  (if (not (file-exists? <pathname>))
      (set! <pathname> (string-append <pathname> (scheme-file-suffix))))
  (call-with-input-file <pathname>
    (lambda (port)
      (let ((old-load-pathname *load-pathname*))
	(set! *load-pathname* <pathname>)
	(do ((o (read port) (read port)))
	    ((eof-object? o))
	  (evl o))
	(set! *load-pathname* old-load-pathname)))))

(define slib:warn
  (lambda args
    (let ((port (current-error-port)))
      (display "Warn: " port)
      (for-each (lambda (x) (display x port)) args))))

;;; define an error procedure for the library
(define slib:error s48-error)

;;; define these as appropriate for your system.
(define slib:tab (s48-ascii->char 9))
(define slib:form-feed (s48-ascii->char 12))

;;; Support for older versions of Scheme.  Not enough code for its own file.
(define (last-pair l) (if (pair? (cdr l)) (last-pair (cdr l)) l))
(define t #t)
(define nil #f)

;;; Define these if your implementation's syntax can support them and if
;;; they are not already defined.

(define (1+ n) (+ n 1))
(define (-1+ n) (+ n -1))
;(define 1- -1+)

(define in-vicinity string-append)

;;; Define SLIB:EXIT to be the implementation procedure to exit or
;;; return if exitting not supported.
(define slib:exit (lambda args #f))

;;; Here for backward compatability
(define scheme-file-suffix
  (case (software-type)
    ((NOSVE) (lambda () "_scm"))
    (else (lambda () ".scm"))))

;;; (SLIB:LOAD-SOURCE "foo") should load "foo.scm" or with whatever
;;; suffix all the module files in SLIB have.  See feature 'SOURCE.

(define (slib:load-source f) (load (string-append f (scheme-file-suffix))))

;;; (SLIB:LOAD-COMPILED "foo") should load the file that was produced
;;; by compiling "foo.scm" if this implementation can compile files.
;;; See feature 'COMPILED.

(define slib:load-compiled load)

;;; At this point SLIB:LOAD must be able to load SLIB files.

(define slib:load slib:load-source)

;;; Scheme48 complains that these are not defined (even though they
;;; won't be called until they are).
(define synclo:load #f)
(define syncase:load #f)
(define macwork:load #f)
(define transcript-on #f)
(define transcript-off #f)

(slib:load (in-vicinity (library-vicinity) "require"))
