;;; "s7.init" Initialization for SLIB for S7        -*-scheme-*-
;;; Author: Aubrey Jaffer
;;;
;;; This code is in the public domain.

;;; S7 is embedded in Snd or Sndlib;
;;; It does not exist as a stand-alone program.

;;@ (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) 's7)

;;@ (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://ccrma.stanford.edu/software/snd/")

;;@ (scheme-implementation-version) should return a string describing
;;; the version the scheme implementation loading this file.
(define scheme-implementation-version s7-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
  (let ((impl-path
	 (or (getenv "S7_IMPLEMENTATION_PATH")
	     (case (software-type)
	       ((unix) "/usr/local/share/snd/")
	       ((vms) "scheme$src:")
	       ((ms-dos) "C:\\Program Files\\snd\\")
	       (else "")))))
    (lambda () impl-path)))

;;@ (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
	  ;; Use this getenv if your implementation supports it.
	  (getenv "SCHEME_LIBRARY_PATH")
	  ;; Use this path if your scheme does not support GETENV
	  ;; or if SCHEME_LIBRARY_PATH is not set.
	  (case (software-type)
	    ((unix) "/usr/local/lib/slib/")
	    ((vms) "lib$scheme:")
	    ((ms-dos) "C:\\Program Files\\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 (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)))))

;@
(define in-vicinity string-append)

;@
(define (user-vicinity)
  (case (software-type)
    ((vms)	"[.]")
    (else	"")))

(define *load-pathname* #f)	 ; *load-path* is a list of dirs in s7

;@
(define vicinity:suffix?
  (let ((suffi
	 (case (software-type)
	   ((amiga)				'(#\: #\/))
	   ((macos thinkc)			'(#\:))
	   ((ms-dos windows atarist os/2)	'(#\\ #\/))
	   ((nosve)				'(#\: #\.))
	   ((unix coherent plan9)		'(#\/))
	   ((vms)				'(#\: #\]))
	   (else
	    (slib:warn "require.scm" 'unknown 'software-type (software-type))
	    "/"))))
    (lambda (chr) (and (memv chr suffi) #t))))
;@
(define (pathname->vicinity pathname)
  (let loop ((i (- (string-length pathname) 1)))
    (cond ((negative? i) "")
	  ((vicinity:suffix? (string-ref pathname i))
	   (substring pathname 0 (+ i 1)))
	  (else (loop (- i 1))))))
(define (program-vicinity)
  (if *load-pathname*
      (pathname->vicinity *load-pathname*)
      (slib:error 'program-vicinity " called; use slib:load to load")))
;@
(define sub-vicinity
  (case (software-type)
    ((vms) (lambda (vic name)
	     (let ((l (string-length vic)))
	       (if (or (zero? (string-length vic))
		       (not (char=? #\] (string-ref vic (- l 1)))))
		   (string-append vic "[" name "]")
		   (string-append (substring vic 0 (- l 1))
				  "." name "]")))))
    (else (let ((*vicinity-suffix*
		 (case (software-type)
		   ((nosve) ".")
		   ((macos thinkc) ":")
		   ((ms-dos windows atarist os/2) "\\")
		   ((unix coherent plan9 amiga) "/"))))
	    (lambda (vic name)
	      (string-append vic name *vicinity-suffix*))))))
;@
(define (make-vicinity <pathname>) <pathname>)
;@
(define with-load-pathname
  (let ((exchange
	 (lambda (new)
	   (let ((old *load-pathname*))
	     (set! *load-pathname* new)
	     old))))
    (lambda (path thunk)
      (let ((old #f))
	(dynamic-wind
	    (lambda () (set! old (exchange path)))
	    thunk
	    (lambda () (exchange old)))))))

;;@ SLIB:FEATURES is a list of symbols naming the (SLIB) features
;;; initially supported by this implementation.
(define slib:features
  '(
    source				;can load scheme source files
					;(SLIB:LOAD-SOURCE "filename")
;;;	compiled			;can load compiled files
					;(SLIB:LOAD-COMPILED "filename")
    vicinity
    srfi-59
    srfi-96

    ;; Scheme report features
    ;; R5RS-compliant implementations should provide all 9 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?
    rev4-optional-procedures	       ;LIST-TAIL, STRING-COPY,
					;STRING-FILL!, and VECTOR-FILL!

    ;; These four features are optional in both R4RS and R5RS

    multiarg/and-		   ;/ and - can take more than 2 args.
    rationalize
;;;	transcript			;TRANSCRIPT-ON and TRANSCRIPT-OFF
    with-file				;has WITH-INPUT-FROM-FILE and
					;WITH-OUTPUT-TO-FILE

;;;	r4rs				;conforms to

;;;	ieee-p1178			;conforms to
;;; I don't know what ieee-p1178 is

;;;	r3rs				;conforms to
;;; I don't know what this means

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

    full-continuation			;can return multiple times
;;;	ieee-floating-point		;conforms to IEEE Standard 754-1985
					;IEEE Standard for Binary
					;Floating-Point Arithmetic.
;;; if this means all the NaN and inf stuff, then s7 does not conform

    ;; Other common features

;;;	srfi-0				;srfi-0, COND-EXPAND finds all srfi-*
;;;	sicp				;runs code from Structure and
					;Interpretation of Computer
					;Programs by Abelson and Sussman.
;;; ?? never tried to run it

    defmacro				;has Common Lisp DEFMACRO
;;;	syntax-case			;has syncase:eval and syncase:load
;;;	record				;has user defined data structures
    string-port			    ;has CALL-WITH-INPUT-STRING and
					;CALL-WITH-OUTPUT-STRING
;;;	sort
;;; s7 has sort! but not merge etc

;;;	pretty-print
    object->string
    format				;Common-lisp output formatting
;;;	trace				;has macros: TRACE and UNTRACE
;;; s7 does have these functions, but not "print-call-stack"

;;;	compiler			;has (COMPILER)
;;;	ed				;(ED) is editor
    system				;posix (system <string>)
    getenv				;posix (getenv <string>)
;;;	program-arguments		;returns list of strings (argv)
;;;	current-time			;returns time in seconds since 1/1/1970

    ;; Implementation Specific features
    random

    ))

;;@ (FILE-POSITION <port> . <k>)
(define (file-position . args) #f)

;;@ (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
  (let ((port (current-output-port)))
    (lambda () port)))

;;@ (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) #f)

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

;;@ 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) #t)

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

;;@ "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 char-code-limit 256)

;;@ MOST-POSITIVE-FIXNUM is used in modular.scm
;;(define most-positive-fixnum #x0FFFFFFF)

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

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

(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)
  (slib:require 'defmacroexpand) (apply defmacro:expand* x '()))
;@
(define (defmacro:load <pathname>)
  (slib:eval-load <pathname> defmacro:eval))
;@
(define slib:warn
  (lambda args
    (let ((cep (current-error-port)))
      (if (provided? 'trace) (print-call-stack cep))
      (display "Warn: " cep)
      (for-each (lambda (x) (display #\space cep) (write x cep)) args)
      (newline cep))))

;;@ define an error procedure for the library
(define slib:error
  (let ((error error))
    (lambda args
      (if (provided? 'trace) (print-call-stack (current-error-port)))
      (apply error args))))
;@
(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? obj) (output-port? obj)))
(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 end) (zero? (system (string-append cmd url end))))
  (or (try "netscape-remote -remote 'openURL(" ")'")
      (try "netscape -remote 'openURL(" ")'")
      (try "netscape '" "'&")
      (try "netscape '" "'")))

;;@ define these as appropriate for your system.
(define slib:tab (integer->char 9))
(define slib:form-feed (integer->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 it and if
;;; they are not already defined.
(define (1+ n) (+ n 1))
(define (-1+ n) (+ n -1))
(define 1- -1+)

;;@ Define SLIB:EXIT to be the implementation procedure to exit or
;;; return if exiting not supported.
(define slib:exit s7-version) 

;;@ 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 ".scm")))

;;@ (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)

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

;;; If your implementation provides syntax-case macros:
;;(define syncase:eval slib:eval)
;;(define syncase:load slib:load-source)

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