;;;"scheme48.init" Initialisation for SLIB for Scheme48	-*-scheme-*-
;;; Author: Aubrey Jaffer
;;;
;;; This code is in the public domain.

,batch on
,load-package floatnums
,config
,load =scheme48/misc/packages.scm
(define-structure slib-primitives
  (export s48-getenv
	  s48-system
	  s48-current-error-port
	  s48-force-output
	  s48-with-handler
	  s48-ascii->char
	  s48-error)
  (open scheme signals ascii extended-ports i/o primitives handle
	unix-getenv			;Comment out for versions >= 0.54
;;;	posix				;Comment out for versions < 0.54
	)
  (begin
    (define s48-getenv
      getenv				;Comment out for versions >= 0.54
;;;      lookup-environment-variable	;Comment out for versions < 0.54
      )
    (define s48-system (lambda (c) (vm-extension 96 c)))
    (define s48-current-error-port current-error-port)
    (define s48-force-output force-output)
    (define s48-with-handler with-handler)
    (define s48-ascii->char ascii->char)
    (define s48-error error)))
,user
,open slib-primitives

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

;;; (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-home-page) should return a (string) URI
;;; (Uniform Resource Identifier) for this scheme implementation's home
;;; page; or false if there isn't one.
(define (scheme-implementation-home-page) "http://s48.org/")

;;; (scheme-implementation-version) should return a string describing
;;; the version of the scheme implementation loading this file.
(define scheme-implementation-version
  (let ((version (getenv "S48_VERSION")))
    (lambda () version)))

;;; (implementation-vicinity) should be defined to be the pathname of
;;; the directory where any auxiliary files to your Scheme
;;; implementation reside.
(define implementation-vicinity
  (let ((vic (getenv "S48_VICINITY")))
    (lambda () vic)))

;;; (library-vicinity) should be defined to be the pathname of the
;;; directory where files of Scheme library functions reside.
(define library-vicinity
  (let ((vic (getenv "SCHEME_LIBRARY_PATH")))
    (lambda () vic)))

;;; (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 (getenv "HOME")))
    (and home
	 (case (software-type)
	   ((UNIX COHERENT MS-DOS)	;V7 unix has a / on HOME
	    (if (eqv? #\/ (string-ref home (+ -1 (string-length home))))
		home
		(string-append home "/")))
	   (else home)))))

(let* ((siv (scheme-implementation-version))
       (num-ver (and siv (string->number siv))))
  (cond ((not num-ver))
	((>= num-ver 0.54)
	 (set! system #f))))

;;; *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")

		       ;; Scheme report features

	r5rs				;conforms to
	eval				;R5RS two-argument eval
	values				;R5RS multiple values
	dynamic-wind			;R5RS dynamic-wind
	macro				;R5RS high level macros
	delay				;has DELAY and FORCE
	multiarg-apply			;APPLY can take more than 2 args.
	char-ready?
	rationalize
	rev4-optional-procedures	;LIST-TAIL, STRING->LIST,
					;LIST->STRING, STRING-COPY,
					;STRING-FILL!, LIST->VECTOR,
					;VECTOR->LIST, and VECTOR-FILL!

	r4rs				;conforms to

	ieee-p1178			;conforms to

;	r3rs				;conforms to

;	rev2-procedures			;SUBSTRING-MOVE-LEFT!,
					;SUBSTRING-MOVE-RIGHT!,
					;SUBSTRING-FILL!,
					;STRING-NULL?, APPEND!, 1+,
					;-1+, <?, <=?, =?, >?, >=?
;	object-hash			;has OBJECT-HASH

;	multiarg/and-			;/ and - can take more than 2 args.
	with-file			;has WITH-INPUT-FROM-FILE and
					;WITH-OUTPUT-TO-FILE
;	transcript			;TRANSCRIPT-ON and TRANSCRIPT-OFF
;	ieee-floating-point		;conforms to IEEE Standard 754-1985
					;IEEE Standard for Binary
					;Floating-Point Arithmetic.
	full-continuation		;can return multiple times

			;; Other common features

;	srfi				;srfi-0, COND-EXPAND finds all srfi-*
;	sicp				;runs code from Structure and
					;Interpretation of Computer
					;Programs by Abelson and Sussman.
	defmacro			;has Common Lisp DEFMACRO
;	record				;has user defined data structures
;	string-port			;has CALL-WITH-INPUT-STRING and
					;CALL-WITH-OUTPUT-STRING
;	sort
;	pretty-print
;	object->string
;	format				;Common-lisp output formatting
;	trace				;has macros: TRACE and UNTRACE
;	compiler			;has (COMPILER)
;	ed				;(ED) is editor
	getenv				;posix (getenv <string>)
;	program-arguments		;returns list of strings (argv)
;	current-time			;returns time in seconds since 1/1/1970
		  ;; Implementation Specific features
	))

(if system				;posix (system <string>)
    (set! *features* (cons 'system *features*)))

;;; (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))))

(define (make-exchanger obj)
  (lambda (rep) (let ((old obj)) (set! obj rep) old)))
(define (open-file filename modes)
  (case modes
    ((r rb) (open-input-file filename))
    ((w wb) (open-output-file filename))
    (else (slib:error 'open-file 'mode? modes))))
(define (port? obj) (or (input-port? port) (output-port? port)))
(define (call-with-open-ports . ports)
  (define proc (car ports))
  (cond ((procedure? proc) (set! ports (cdr ports)))
	(else (set! ports (reverse ports))
	      (set! proc (car ports))
	      (set! ports (reverse (cdr ports)))))
  (let ((ans (apply proc ports)))
    (for-each close-port ports)
    ans))
(define (close-port port)
  (cond ((input-port? port)
	 (close-input-port port)
	 (if (output-port? port) (close-output-port port)))
	((output-port? port) (close-output-port port))
	(else (slib:error 'close-port 'port? port))))

(define (browse-url url)
  (define (try cmd) (eqv? 0 (system (sprintf #f cmd url))))
  (or (try "netscape-remote -remote 'openURL(%s)'")
      (try "netscape -remote 'openURL(%s)'")
      (try "netscape '%s'&")
      (try "netscape '%s'")))

;;; "rationalize" adjunct procedures.
(define (find-ratio x e)
  (let ((rat (rationalize x e)))
    (list (numerator rat) (denominator rat))))
(define (find-ratio-between x y)
  (find-ratio (/ (+ x y) 2) (/ (- x y) 2)))

;;; 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)))))

;;; Workaround atan bug
(define two-arg:atan atan)
(define (atan y . x)
  (if (null? x) (two-arg:atan y 1) (two-arg:atan y (car x))))
;;; asin is totally busted
(define (asin y) (two-arg:atan y (sqrt (- 1 (* y y)))))

;;; Workaround inexact->exact and exact->inexact bugs.
(define inexact->exact
  (let ((i->e inexact->exact))
    (lambda (z)
      (if (exact? z) z (i->e z)))))
(define exact->inexact
  (let ((e->i exact->inexact))
    (lambda (z)
      (if (inexact? z) z (e->i z)))))

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

;;; Return argument
(define identity values)

;;; 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:load macro:load)

(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 ((cep (current-error-port)))
      (if (provided? 'trace) (print-call-stack cep))
      (display "Warn: " cep)
      (write (car args) cep)
      (newline cep)
      (for-each (lambda (x)
		  (display "      " cep)
		  (write x cep)
		  (newline cep))
		(cdr args)))))

;;; define an error procedure for the library
(define (slib:error . args)
  (if (provided? 'trace) (print-call-stack (current-error-port)))
  (apply s48-error args))

;;; 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)

;;; Jacques Mequin wins the Spring 2001 SLIB extreme cleverness award:
(define-syntax defmacro
  (lambda (e r c)
    (let* ((e-fields (cdr e))
	   (macro-name (car e-fields))
	   (macro-args (cdr e-fields))
	   (slib-store (eval 'defmacro:eval (interaction-environment))))
      (slib-store `(defmacro ,macro-name ,@macro-args)))
    `(define-syntax ,(cadr e)
       (lambda (em rm cm)
	 (let ((macro-name ',(cadr e))
	       (macro-args (cdr em))
	       (slib-eval (eval 'macroexpand-1 (interaction-environment))))
	   (slib-eval `(,macro-name ,@macro-args)))))))

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

;;; Needed to support defmacro
(require 'defmacroexpand)
(define *args* '())
(define (program-arguments) (cons "scheme48" *args*))
(set! *catalog* #f)

,collect
,batch off
,dump slib.image "(slib 3a1)"
,exit