;;; "pscheme.init" SLIB init file for Pocket Scheme	-*-scheme-*-
;;; Author: Ben Goetter <goetter@mazama.net>
;;;   last revised for 1.1.0 on 16 October 2000
;;; Initial work for 0.2.3 by Robert Goldman (goldman@htc.honeywell.com)
;;; SLIB orig Author: Aubrey Jaffer (agj @ alum.mit.edu)
;;;
;;; This code is in the public domain.

; best fit for Windows CE?
(define (software-type) 'MS-DOS)

(define (scheme-implementation-type) 'Pocket-Scheme)
(define (scheme-implementation-version)
  (let ((v (version)))
    (string-append
      (number->string (car v)) "."
      (number->string (cadr v)) "."
      (number->string (caddr v)))))
(define (scheme-implementation-home-page) "http://www.mazama.net/scheme/pscheme.htm")

(define (implementation-vicinity) "\\Program Files\\Pocket Scheme\\")
(define (library-vicinity) (in-vicinity (implementation-vicinity) "slib\\"))
(define (home-vicinity)	"\\My Documents\\")

;(define (implementation-vicinity) "D:\\SRC\\PSCHEME\\BUILD\\TARGET\\X86\\NT\\DBG\\")
;(define (library-vicinity) "D:\\SRC\\SLIB\\")
;(define (home-vicinity) "D:\\SRC\\PSCHEME\\")
;@
(define in-vicinity string-append)
;@
(define (user-vicinity)
  (case (software-type)
    ((vms)	"[.]")
    (else	"")))

(define *load-pathname* #f)
;@
(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)))))))

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

		       ;; 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

;;;	r3rs				;conforms to

;;;	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.

			;; 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
; Undef this to get the SLIB TRACE macros
;;;	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)
;;;	current-time			;returns time in seconds since 1/1/1970

		  ;; Implementation Specific features

	))

;;; (OUTPUT-PORT-WIDTH <port>)
;;; (OUTPUT-PORT-HEIGHT <port>)
;; $BUGBUG completely bogus values.
(define (output-port-width . arg) 79)
(define (output-port-height . arg) 12)

;;; (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)
 (with-handlers (((lambda (x) #t) (lambda (x) #f)))
  (close-input-port (open-input-file f))
  #t))

;; pscheme: current-error-port, delete-file, force-output already defined

(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'")))

;;; CHAR-CODE-LIMIT is one greater than the largest integer which can
;;; be returned by CHAR->INTEGER.
;(define char-code-limit
; (with-handlers (
;  ((lambda (x) #t) (lambda (x) 256))
;                )
;  (integer->char 65535)
;  65536))
;;; Currently there are only three clients of this symbol.
;;; Following observations relate to PScheme 0.3.5, JACAL 1a9, SLIB 2c5.
;;; JACAL: crashes when set to 65536.
;;; make-crc: extremely inefficient when set to 65536, spending forever in init
;;; precedence-parse: ignores any setting in excess of 256
;;; So we patch it to 256.
(define char-code-limit 256)

;;; MOST-POSITIVE-FIXNUM is used in modular.scm
;;; This is the most positive immediate-value fixnum in PScheme.
(define most-positive-fixnum #x07FFFFFF)

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

;;; 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 defmacro in terms of our define-macro
(define-macro (defmacro name args . body)
 `(define-macro (,name ,@args) ,@body))

; following defns removed in 0.6.3 while I rethink macro support
;(define defmacro? macro?)
;(define macroexpand expand-macro)
;(define macroexpand-1 expand-macro-1)

(define gentemp gensym)

(define base:eval slib:eval)
(define defmacro:eval slib:eval)
;; slib:eval-load definition moved to "require.scm"

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

(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)

;;; As announced by feature string-port
(define (call-with-output-string t)
 (let* ((p (open-output-string))
        (r (t p))
        (s (get-output-string p)))
  (close-output-port p)
  s))

(define (call-with-input-string s t)
 (let* ((p (open-input-string s))
        (r (t p)))
  (close-input-port p)
  r))

;;; 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 exit)

;;; 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)
 (if (not (file-exists? f))
  (set! f (string-append f (scheme-file-suffix))))
 (load f))

;;; (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)

;;; Pscheme and SLIB both define REQUIRE, so dispatch on argument type.
;;; The SLIB REQUIRE does accept strings, though this facility seems never to be used.
(define pscheme:require require)
(slib:load (in-vicinity (library-vicinity) "require"))
(define slib:require require)
(define (require x)
 (if (string? x) (pscheme:require x) (slib:require x)))