;    Initialization file for TinySCHEME 1.39
;
; Copyright (c) 2000, Dimitrios Souflis
; All rights reserved.
; 
; Redistribution and use in source and binary forms, with or without
; modification, are permitted provided that the following conditions are
; met:
; 
; Redistributions of source code must retain the above copyright notice,
; this list of conditions and the following disclaimer.
; 
; Redistributions in binary form must reproduce the above copyright
; notice, this list of conditions and the following disclaimer in the
; documentation and/or other materials provided with the distribution.
; 
; Neither the name of Dimitrios Souflis nor the names of the
; contributors may be used to endorse or promote products derived from
; this software without specific prior written permission.
; 
; THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
; ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
; LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 
; A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR 
; CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
; EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
; PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
; PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
; LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
; NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
; SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;

; Per R5RS, up to four deep compositions should be defined
(define (caar x) (car (car x)))
(define (cadr x) (car (cdr x)))
(define (cdar x) (cdr (car x)))
(define (cddr x) (cdr (cdr x)))
(define (caaar x) (car (car (car x))))
(define (caadr x) (car (car (cdr x))))
(define (cadar x) (car (cdr (car x))))
(define (caddr x) (car (cdr (cdr x))))
(define (cdaar x) (cdr (car (car x))))
(define (cdadr x) (cdr (car (cdr x))))
(define (cddar x) (cdr (cdr (car x))))
(define (cdddr x) (cdr (cdr (cdr x))))
(define (caaaar x) (car (car (car (car x)))))
(define (caaadr x) (car (car (car (cdr x)))))
(define (caadar x) (car (car (cdr (car x)))))
(define (caaddr x) (car (car (cdr (cdr x)))))
(define (cadaar x) (car (cdr (car (car x)))))
(define (cadadr x) (car (cdr (car (cdr x)))))
(define (caddar x) (car (cdr (cdr (car x)))))
(define (cadddr x) (car (cdr (cdr (cdr x)))))
(define (cdaaar x) (cdr (car (car (car x)))))
(define (cdaadr x) (cdr (car (car (cdr x)))))
(define (cdadar x) (cdr (car (cdr (car x)))))
(define (cdaddr x) (cdr (car (cdr (cdr x)))))
(define (cddaar x) (cdr (cdr (car (car x)))))
(define (cddadr x) (cdr (cdr (car (cdr x)))))
(define (cdddar x) (cdr (cdr (cdr (car x)))))
(define (cddddr x) (cdr (cdr (cdr (cdr x)))))

(macro (unless form)
     `(if (not ,(cadr form)) (begin ,@(cddr form))))

(macro (when form)
     `(if ,(cadr form) (begin ,@(cddr form))))

; DEFINE-MACRO Contributed by Andy Gaynor
(macro (define-macro dform)
  (if (symbol? (cadr dform))
    `(macro ,@(cdr dform))
    (let ((form (gensym)))
      `(macro (,(caadr dform) ,form)
         (apply (lambda ,(cdadr dform) ,@(cddr dform)) (cdr ,form))))))

; Utilities for math. Notice that inexact->exact is primitive,
; but exact->inexact is not.
(define exact? integer?)
(define (inexact? x) (and (real? x) (not (integer? x))))
(define (even? n) (= (remainder n 2) 0))
(define (odd? n) (not (= (remainder n 2) 0)))
(define (zero? n) (= n 0))
(define (positive? n) (> n 0))
(define (negative? n) (< n 0))
(define complex? number?)
(define rational? real?)
(define (abs n) (if (>= n 0) n (- n)))
(define (exact->inexact n) (* n 1.0))
(define (<> n1 n2) (not (= n1 n2)))
(define (max . lst)
     (foldr (lambda (a b) (if (> a b) a b)) (car lst) (cdr lst)))
(define (min . lst)
     (foldr (lambda (a b) (if (< a b) a b)) (car lst) (cdr lst)))
(define (succ x) (+ x 1))
(define (pred x) (- x 1))
(define (gcd a b)
  (let ((aa (abs a))
	(bb (abs b)))
     (if (= bb 0)
          aa
          (gcd bb (remainder aa bb)))))
(define (lcm a b)
     (if (or (= a 0) (= b 0))
          0
          (abs (* (quotient a (gcd a b)) b))))

(define call/cc call-with-current-continuation)

(define (string . charlist)
     (list->string charlist))

(define (list->string charlist)
     (let* ((len (length charlist))
            (newstr (make-string len))
            (fill-string!
               (lambda (str i len charlist)
                    (if (= i len)
                         str
                         (begin (string-set! str i (car charlist))
                         (fill-string! str (+ i 1) len (cdr charlist)))))))
          (fill-string! newstr 0 len charlist)))

(define (string-fill! s e)
     (let ((n (string-length s)))
          (let loop ((i 0))
               (if (= i n)
                    s
                    (begin (string-set! s i e) (loop (succ i)))))))

(define (string->list s)
     (let loop ((n (pred (string-length s))) (l '()))
          (if (= n -1)
               l
               (loop (pred n) (cons (string-ref s n) l)))))

(define (string-copy str)
     (string-append str))

(define (string->anyatom str pred)
     (let* ((a (string->atom str)))
       (if (pred a) a
	   (error "string->xxx: not a xxx" a))))

(define (string->number str) (string->anyatom str number?))

(define (anyatom->string n pred)
  (if (pred n)
      (atom->string n)
      (error "xxx->string: not a xxx" n)))
  

(define (number->string n) (anyatom->string n number?))    

(define (char-cmp? cmp a b)
     (cmp (char->integer a) (char->integer b)))
(define (char-ci-cmp? cmp a b)
     (cmp (char->integer (char-downcase a)) (char->integer (char-downcase b))))

(define (char=? a b) (char-cmp? = a b))
(define (char<? a b) (char-cmp? < a b))
(define (char>? a b) (char-cmp? > a b))
(define (char<=? a b) (char-cmp? <= a b))
(define (char>=? a b) (char-cmp? >= a b))

(define (char-ci=? a b) (char-ci-cmp? = a b))
(define (char-ci<? a b) (char-ci-cmp? < a b))
(define (char-ci>? a b) (char-ci-cmp? > a b))
(define (char-ci<=? a b) (char-ci-cmp? <= a b))
(define (char-ci>=? a b) (char-ci-cmp? >= a b))

; Note the trick of returning (cmp x y)
(define (string-cmp? chcmp cmp a b)
     (let ((na (string-length a)) (nb (string-length b)))
          (let loop ((i 0))
               (cond
                    ((= i na)
                         (if (= i nb) (cmp 0 0) (cmp 0 1)))
                    ((= i nb)
                         (cmp 1 0))
                    ((chcmp = (string-ref a i) (string-ref b i))
                         (loop (succ i)))
                    (else
                         (chcmp cmp (string-ref a i) (string-ref b i)))))))


(define (string=? a b) (string-cmp? char-cmp? = a b))
(define (string<? a b) (string-cmp? char-cmp? < a b))
(define (string>? a b) (string-cmp? char-cmp? > a b))
(define (string<=? a b) (string-cmp? char-cmp? <= a b))
(define (string>=? a b) (string-cmp? char-cmp? >= a b))

(define (string-ci=? a b) (string-cmp? char-ci-cmp? = a b))
(define (string-ci<? a b) (string-cmp? char-ci-cmp? < a b))
(define (string-ci>? a b) (string-cmp? char-ci-cmp? > a b))
(define (string-ci<=? a b) (string-cmp? char-ci-cmp? <= a b))
(define (string-ci>=? a b) (string-cmp? char-ci-cmp? >= a b))

(define (list . x) x)

(define (foldr f x lst)
     (if (null? lst)
          x
          (foldr f (f x (car lst)) (cdr lst))))

(define (unzip1-with-cdr . lists)
  (unzip1-with-cdr-iterative lists '() '()))

(define (unzip1-with-cdr-iterative lists cars cdrs)
  (if (null? lists)
      (cons cars cdrs)
      (let ((car1 (caar lists))
	    (cdr1 (cdar lists)))
	(unzip1-with-cdr-iterative 
	 (cdr lists) 
	 (append cars (list car1))
	 (append cdrs (list cdr1))))))

(define (map proc . lists)
  (if (null? lists)
      (apply proc)
      (if (null? (car lists))
	  '()
	  (let* ((unz (apply unzip1-with-cdr lists))
		 (cars (car unz))
		 (cdrs (cdr unz)))
	    (cons (apply proc cars) (apply map (cons proc cdrs)))))))

(define (for-each proc . lists)
  (if (null? lists)
      (apply proc)
      (if (null? (car lists))
	  #t
	  (let* ((unz (apply unzip1-with-cdr lists))
		 (cars (car unz))
		 (cdrs (cdr unz)))
	    (apply proc cars) (apply map (cons proc cdrs))))))

(define (list-tail x k)
    (if (zero? k)
        x
        (list-tail (cdr x) (- k 1))))

(define (list-ref x k)
    (car (list-tail x k)))

(define (last-pair x)
    (if (pair? (cdr x))
        (last-pair (cdr x))
        x))

(define (head stream) (car stream))

(define (tail stream) (force (cdr stream)))

(define (vector-equal? x y)
     (and (vector? x) (vector? y) (= (vector-length x) (vector-length y))
          (let ((n (vector-length x)))
               (let loop ((i 0))
                    (if (= i n)
                         #t
                         (and (equal? (vector-ref x i) (vector-ref y i))
                              (loop (succ i))))))))

(define (list->vector x)
     (apply vector x))

(define (vector-fill! v e)
     (let ((n (vector-length v)))
          (let loop ((i 0))
               (if (= i n)
                    v
                    (begin (vector-set! v i e) (loop (succ i)))))))

(define (vector->list v)
     (let loop ((n (pred (vector-length v))) (l '()))
          (if (= n -1)
               l
               (loop (pred n) (cons (vector-ref v n) l)))))

;; The following quasiquote macro is due to Eric S. Tiedemann.
;;   Copyright 1988 by Eric S. Tiedemann; all rights reserved.
;;
;; Subsequently modified to handle vectors: D. Souflis

(macro
 quasiquote
 (lambda (l)
   (define (mcons f l r)
     (if (and (pair? r)
              (eq? (car r) 'quote)
              (eq? (car (cdr r)) (cdr f))
              (pair? l)
              (eq? (car l) 'quote)
              (eq? (car (cdr l)) (car f)))
         (if (or (procedure? f) (number? f) (string? f))
               f
               (list 'quote f))
         (if (eqv? l vector)
               (apply l (eval r))
               (list 'cons l r)
               )))
   (define (mappend f l r)
     (if (or (null? (cdr f))
             (and (pair? r)
                  (eq? (car r) 'quote)
                  (eq? (car (cdr r)) '())))
         l
         (list 'append l r)))
   (define (foo level form)
     (cond ((not (pair? form))
               (if (or (procedure? form) (number? form) (string? form))
                    form
                    (list 'quote form))
               )
           ((eq? 'quasiquote (car form))
            (mcons form ''quasiquote (foo (+ level 1) (cdr form))))
           (#t (if (zero? level)
                   (cond ((eq? (car form) 'unquote) (car (cdr form)))
                         ((eq? (car form) 'unquote-splicing)
                          (error "Unquote-splicing wasn't in a list:"
                                 form))
                         ((and (pair? (car form))
                               (eq? (car (car form)) 'unquote-splicing))
                          (mappend form (car (cdr (car form)))
                                   (foo level (cdr form))))
                         (#t (mcons form (foo level (car form))
                                         (foo level (cdr form)))))
                   (cond ((eq? (car form) 'unquote)
                          (mcons form ''unquote (foo (- level 1)
                                                     (cdr form))))
                         ((eq? (car form) 'unquote-splicing)
                          (mcons form ''unquote-splicing
                                      (foo (- level 1) (cdr form))))
                         (#t (mcons form (foo level (car form))
                                         (foo level (cdr form)))))))))
   (foo 0 (car (cdr l)))))


;;;;; atom? and equal? written by a.k

;;;; atom?
(define (atom? x)
  (not (pair? x)))

;;;;    equal?
(define (equal? x y)
     (cond
          ((pair? x)
               (and (pair? y)
                    (equal? (car x) (car y))
                    (equal? (cdr x) (cdr y))))
          ((vector? x)
               (and (vector? y) (vector-equal? x y)))
          ((string? x)
               (and (string? y) (string=? x y)))
          (else (eqv? x y))))

;;;; (do ((var init inc) ...) (endtest result ...) body ...)
;;
(macro do
  (lambda (do-macro)
    (apply (lambda (do vars endtest . body)
             (let ((do-loop (gensym)))
               `(letrec ((,do-loop
                           (lambda ,(map (lambda (x)
                                           (if (pair? x) (car x) x))
                                      `,vars)
                             (if ,(car endtest)
                               (begin ,@(cdr endtest))
                               (begin
                                 ,@body
                                 (,do-loop
                                   ,@(map (lambda (x)
                                            (cond
                                              ((not (pair? x)) x)
                                              ((< (length x) 3) (car x))
                                              (else (car (cdr (cdr x))))))
                                       `,vars)))))))
                  (,do-loop
                    ,@(map (lambda (x)
                             (if (and (pair? x) (cdr x))
                               (car (cdr x))
                               '()))
                        `,vars)))))
      do-macro)))

;;;; generic-member
(define (generic-member cmp obj lst)
  (cond
    ((null? lst) #f)
    ((cmp obj (car lst)) lst)
    (else (generic-member cmp obj (cdr lst)))))

(define (memq obj lst)
     (generic-member eq? obj lst))
(define (memv obj lst)
     (generic-member eqv? obj lst))
(define (member obj lst)
     (generic-member equal? obj lst))

;;;; generic-assoc
(define (generic-assoc cmp obj alst)
     (cond
          ((null? alst) #f)
          ((cmp obj (caar alst)) (car alst))
          (else (generic-assoc cmp obj (cdr alst)))))

(define (assq obj alst)
     (generic-assoc eq? obj alst))
(define (assv obj alst)
     (generic-assoc eqv? obj alst))
(define (assoc obj alst)
     (generic-assoc equal? obj alst))

(define (acons x y z) (cons (cons x y) z))

;;;; Utility to ease macro creation
(define (macro-expand form)
     ((eval (get-closure-code (eval (car form)))) form))

;;;; Handy for imperative programs
;;;; Used as: (define-with-return (foo x y) .... (return z) ...)
(macro (define-with-return form)
     `(define ,(cadr form)
          (call/cc (lambda (return) ,@(cddr form)))))

;;;; Simple exception handling
;
;    Exceptions are caught as follows:
;
;         (catch (do-something to-recover and-return meaningful-value)
;              (if-something goes-wrong)
;              (with-these calls))
;
;    "Catch" establishes a scope spanning multiple call-frames
;    until another "catch" is encountered.
;
;    Exceptions are thrown with:
;
;         (throw "message")
;
;    If used outside a (catch ...), reverts to (error "message)

(define *handlers* (list))

(define (push-handler proc)
     (set! *handlers* (cons proc *handlers*)))

(define (pop-handler)
     (let ((h (car *handlers*)))
          (set! *handlers* (cdr *handlers*))
          h))

(define (more-handlers?)
     (pair? *handlers*))

(define (throw . x)
     (if (more-handlers?)
          (apply (pop-handler))
          (apply error x)))

(macro (catch form)
     (let ((label (gensym)))
          `(call/cc (lambda (exit)
               (push-handler (lambda () (exit ,(cadr form))))
               (let ((,label (begin ,@(cddr form))))
                    (pop-handler)
                    ,label)))))

(define *error-hook* throw)


;;;;; Definition of MAKE-ENVIRONMENT, to be used with two-argument EVAL

(macro (make-environment form)
     `(apply (lambda ()
               ,@(cdr form)
               (current-environment))))

(define-macro (eval-polymorphic x . envl)
  (display envl)
  (let* ((env (if (null? envl) (current-environment) (eval (car envl))))
         (xval (eval x env)))
    (if (closure? xval)
	(make-closure (get-closure-code xval) env)
	xval)))

; Redefine this if you install another package infrastructure
; Also redefine 'package'
(define *colon-hook* eval)

;;;;; I/O

(define (input-output-port? p)
     (and (input-port? p) (output-port? p)))

(define (close-port p)
     (cond 
          ((input-output-port? p) (close-input-port (close-output-port p)))
          ((input-port? p) (close-input-port p))
          ((output-port? p) (close-output-port p))
          (else (throw "Not a port" p))))

(define (call-with-input-file s p)
     (let ((inport (open-input-file s)))
          (if (eq? inport #f)
               #f
               (let ((res (p inport)))
                    (close-input-port inport)
                    res))))

(define (call-with-output-file s p)
     (let ((outport (open-output-file s)))
          (if (eq? outport #f)
               #f
               (let ((res (p outport)))
                    (close-output-port outport)
                    res))))

(define (with-input-from-file s p)
     (let ((inport (open-input-file s)))
          (if (eq? inport #f)
               #f
               (let ((prev-inport (current-input-port)))
                    (set-input-port inport)
                    (let ((res (p)))
                         (close-input-port inport)
                         (set-input-port prev-inport)
                         res)))))

(define (with-output-to-file s p)
     (let ((outport (open-output-file s)))
          (if (eq? outport #f)
               #f
               (let ((prev-outport (current-output-port)))
                    (set-output-port outport)
                    (let ((res (p)))
                         (close-output-port outport)
                         (set-output-port prev-outport)
                         res)))))

(define (with-input-output-from-to-files si so p)
     (let ((inport (open-input-file si))
           (outport (open-input-file so)))
          (if (not (and inport outport))
               (begin
                    (close-input-port inport)
                    (close-output-port outport)
                    #f)
               (let ((prev-inport (current-input-port))
                     (prev-outport (current-output-port)))
                    (set-input-port inport)
                    (set-output-port outport)
                    (let ((res (p)))
                         (close-input-port inport)
                         (close-output-port outport)
                         (set-input-port prev-inport)
                         (set-output-port prev-outport)
                         res)))))

; Random number generator (maximum cycle)
(define *seed* 1)
(define (random-next)
     (let* ((a 16807) (m 2147483647) (q (quotient m a)) (r (modulo m a)))
          (set! *seed*
               (-   (* a (- *seed*
                         (* (quotient *seed* q) q)))
                    (* (quotient *seed* q) r)))
          (if (< *seed* 0) (set! *seed* (+ *seed* m)))
          *seed*))
;; SRFI-0 
;; COND-EXPAND
;; Implemented as a macro
(define *features* '(srfi-0))

(define-macro (cond-expand . cond-action-list)
  (cond-expand-runtime cond-action-list))

(define (cond-expand-runtime cond-action-list)
  (if (null? cond-action-list)
      #t
      (if (cond-eval (caar cond-action-list))
          `(begin ,@(cdar cond-action-list))
          (cond-expand-runtime (cdr cond-action-list)))))

(define (cond-eval-and cond-list)
  (foldr (lambda (x y) (and (cond-eval x) (cond-eval y))) #t cond-list))

(define (cond-eval-or cond-list)
  (foldr (lambda (x y) (or (cond-eval x) (cond-eval y))) #f cond-list))

(define (cond-eval condition)
  (cond ((symbol? condition)
	 (if (member condition *features*) #t #f))
	((eq? condition #t) #t)
	((eq? condition #f) #f)
	(else (case (car condition)
		((and) (cond-eval-and (cdr condition)))
		((or) (cond-eval-or (cdr condition)))
		((not) (if (not (null? (cddr condition)))
			   (error "cond-expand : 'not' takes 1 argument")
			   (not (cond-eval (cadr condition)))))
		(else (error "cond-expand : unknown operator" (car condition)))))))

(gc-verbose #f)