;;;"vscm.init" Configuration of *features* for VSCM	-*-scheme-*-
;Copyright (C) 1994, 1996, 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.

;;; From: Matthias Blume <blume@cs.Princeton.EDU>
;;; Date: Tue, 1 Mar 1994 11:42:31 -0500
;;; Disclaimer: The code below is only a quick hack.  If I find some
;;; time to spare I might get around to make some more things work.

;;; You have to provide ``vscm.init'' as an explicit command line
;;; argument.  Since this is not very nice I would recommend the
;;; following installation procedure:

;1. run scheme
;2. (load "vscm.init")
;3. (slib:dump "dumpfile")
;3. mv dumpfile place-where-vscm-standard-bootfile-resides, e.g.
;   mv dumpfile /usr/local/vscm/lib/scheme-boot
;   (In this case vscm should have been compiled with flag
;    -DDEFAULT_BOOTFILE='"/usr/local/vscm/lib/scheme-boot"'.  See
;    Makefile (definition of DDP) for details.)

(define (slib:dump dump-to-file)
  (let ((args (dump dump-to-file)))
    (if args
	(begin
	  (display "[SLIB available]")
	  (newline)
	  (((mcm) 'toplevel) args))
	(quit))))

;;; Caveat: While playing with this code I discovered a nasty bug.
;;; (Something is wrong with my ``restore'' code -- it seems to break
;;; on 64 bit machines (not always, though).)  It works on MIPS, etc.

;;; (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) 'Vscm)

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

(define (scheme-implementation-version) "?")

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

(define (implementation-vicinity)
  (case (software-type)
    ((UNIX)	 "/usr/local/src/scheme/")
    ((VMS)	"scheme$src:")
    ((MS-DOS)	"C:\\scheme\\")))

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

(define library-vicinity
  (let ((library-path
	 (or (getenv "SCHEME_LIBRARY_PATH")
	     ;; Uses this path if SCHEME_LIBRARY_PATH is not set.
	     (case (software-type)
	       ((UNIX) "/usr/local/lib/slib/")
	       ((VMS) "lib$scheme:")
	       ((MS-DOS) "C:\\SLIB\\")
	       (else "")))))
    (lambda () library-path)))

;;; (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.  Suggestions for features are:

(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
;	rev3-report			;conforms to
	ieee-p1178			;conforms to
;	sicp				;runs code from Structure and
					;Interpretation of Computer
					;Programs by Abelson and Sussman.
	rev4-optional-procedures	;LIST-TAIL, STRING->LIST,
					;LIST->STRING, STRING-COPY,
					;STRING-FILL!, LIST->VECTOR,
					;VECTOR->LIST, and VECTOR-FILL!
	rev3-procedures			;LAST-PAIR, T, and NIL
;	rev2-procedures			;SUBSTRING-MOVE-LEFT!,
					;SUBSTRING-MOVE-RIGHT!,
					;SUBSTRING-FILL!,
					;STRING-NULL?, APPEND!, 1+,
					;-1+, <?, <=?, =?, >?, >=?
	multiarg/and-			;/ and - can take more than 2 args.
	multiarg-apply			;APPLY can take more than 2 args.
	rationalize
	delay				;has DELAY and FORCE
	with-file			;has WITH-INPUT-FROM-FILE and
					;WITH-OUTPUT-FROM-FILE
	string-port			;has CALL-WITH-INPUT-STRING and
					;CALL-WITH-OUTPUT-STRING
;	transcript			;TRANSCRIPT-ON and TRANSCRIPT-OFF
;	char-ready?
;	macro				;has R4RS high level macros
;	defmacro			;has Common Lisp DEFMACRO
	eval				;SLIB:EVAL is single argument eval
;	record				;has user defined data structures
	values				;proposed multiple values
;	dynamic-wind			;proposed dynamic-wind
	ieee-floating-point		;conforms to
	full-continuation		;can return multiple times
;	object-hash			;has OBJECT-HASH

;	sort
;	queue				;queues
;	pretty-print
	object->string
;	format
;	trace				;has macros: TRACE and UNTRACE
;	compiler			;has (COMPILER)
;	ed				;(ED) is editor
	system				;posix (system <string>)
	getenv				;posix (getenv <string>)
	program-arguments		;returns list of strings (argv)
;	Xwindows			;X support
;	curses				;screen management package
;	termcap				;terminal description package
;	terminfo			;sysV terminal description
	))

;;; (OBJECT->STRING obj)  -- analogous to WRITE
(define object->string string-write)

;;; (PROGRAM-ARGUMENTS)
;;; 
(define (program-arguments) command-line-arguments)

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

;;; (CURRENT-ERROR-PORT)
(define current-error-port
  (standard-port 2))

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

;;; (FILE-EXISTS? <string>)
(define (file-exists? f)
  (system (string-append "test -f " f)))

;;; (DELETE-FILE <string>)
(define (delete-file f)
  (remove-file f))

;;; FORCE-OUTPUT flushes any pending output on optional arg output port
(define force-output flush)

;;; CALL-WITH-INPUT-STRING and CALL-WITH-OUTPUT-STRING are the string
;;; port versions of CALL-WITH-*PUT-FILE.

(define (call-with-output-string proc)
  (let ((outsp (open-output-string)))
    (proc outsp)
    (close-output-port outsp)))

(define (call-with-input-string string proc)
  (let* ((insp (open-input-string string))
	 (res (proc insp)))
    (close-input-port insp)
    res))

;;; Implementation of string ports using generic ports
(define (open-input-string s)

  (let ((l (string-length s))
	(eof (call-with-values (lambda () (string-read "")) (lambda (x y) x))))

    (define (read)
      (call-with-values
       (lambda ()
	 (string-read s))
       (lambda (obj res)
	 (set! s res)
	 (set! l (string-length res))
	 obj)))

  (define (read-char)
    (if (zero? l)
	eof
	(let ((c (string-ref s 0)))
	  (set! s (substring s 1 l))
	  (set! l (- l 1))
	  c)))

  (define (peek-char)
    (if (zero? l) eof (string-ref s 0)))

  (define (char-ready?) #t)

  (define (close) s)

  (open-input-generic read read-char peek-char char-ready? close)))

(define (open-output-string)

  (let ((s ""))

    (define (write x)
      (set! s (string-append s (string-write x)))
      x)

    (define (display x)
      (set! s (string-append s (string-display x)))
      x)

    (define (write-char x)
      (set! s (string-append s (string x)))
      x)

    (define (newline)
      (set! s (string-append s "\n"))
      #f)

    (define (flush) #f)

    (define (close) s)

    (open-output-generic write display write-char newline flush close)))

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

;;; MOST-POSITIVE-FIXNUM is used in modular.scm
(define most-positive-fixnum #x0fffffff)

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

;;; If your implementation provides eval SLIB:EVAL is single argument
;;; eval using the top-level (user) environment.
(define slib:eval eval)

;;; If your implementation provides R4RS macros:
(define macro:eval slib:eval)
(define macro:load load)

(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 error)

;;; define these as appropriate for your system.
(define slib:tab #\Tab)
(define slib:form-feed #\d12)

;;; 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 it 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
    (cond ((null? args) (quit))
	  ((eqv? #t (car args)) (quit))
	  ((eqv? #f (car args)) (quit 1))
	  (else (quit (car args))))))

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

;;; (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)

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