csi.scm

;;;; csi.scm - Interpreter stub for CHICKEN
;
; Copyright (c) 2008-2011, The Chicken Team
; Copyright (c) 2000-2007, Felix L. Winkelmann
; 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 the author nor the names of its 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 COPYRIGHT HOLDERS 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.


(declare
  (uses chicken-syntax ports extras)
  (usual-integrations)
  (disable-interrupts)
  (compile-syntax)
  (foreign-declare #<<EOF
#if defined(HAVE_DIRECT_H)
# include <direct.h>
#else
# define _getcwd(buf, len)       NULL
#endif
EOF
) )

(include "banner")

(private csi 
  print-usage print-banner
  run hexdump del 
  parse-option-string chop-separator lookup-script-file
  report describe dump hexdump bytevector-data get-config
  deldups tty-input?
  history-list history-count history-add history-ref history-clear history-show)

(declare
  (always-bound
    ##sys#windows-platform)
  (hide parse-option-string bytevector-data member* canonicalize-args 
	describer-table dirseparator? circular-list? improper-pairs?
	show-frameinfo selected-frame select-frame copy-from-frame
	findall command-table default-editor) )


;;; Parameters:

(define-constant init-file ".csirc")

(set! ##sys#repl-print-length-limit 2048)
(set! ##sys#features (cons #:csi ##sys#features))
(set! ##sys#notices-enabled #t)

(define editor-command (make-parameter #f))
(define selected-frame #f)

(define default-editor 
  (or (get-environment-variable "EDITOR")
      (get-environment-variable "VISUAL")
      (if (get-environment-variable "EMACS")
	  "emacsclient"
	  "vi")))			; shudder


;;; Print all sorts of information:

(define (print-usage)
  (display #<<EOF
usage: csi [FILENAME | OPTION ...]

  `csi' is the CHICKEN interpreter.
  
  FILENAME is a Scheme source file name with optional extension. OPTION may be
  one of the following:

    -h  -help  --help             display this text and exit
    -v  -version                  display version and exit
        -release                  print release number and exit
    -i  -case-insensitive         enable case-insensitive reading
    -e  -eval EXPRESSION          evaluate given expression
    -p  -print EXPRESSION         evaluate and print result(s)
    -P  -pretty-print EXPRESSION  evaluate and print result(s) prettily
    -D  -feature SYMBOL           register feature identifier
        -no-feature SYMBOL        disable built-in feature identifier
    -q  -quiet                    do not print banner

EOF
)
  (display #<#EOF
    -n  -no-init                  do not load initialization file #{#\`} #{init-file} #{#\'}

EOF
)
  (display  #<<EOF
    -b  -batch                    terminate after command-line processing
    -w  -no-warnings              disable all warnings
    -K  -keyword-style STYLE      enable alternative keyword-syntax
                                   (prefix, suffix or none)
        -no-parentheses-synonyms  disables list delimiter synonyms
        -no-symbol-escape         disables support for escaped symbols
        -r5rs-syntax              disables the Chicken extensions to
                                   R5RS syntax
    -s  -script PATHNAME          use interpreter for shell scripts
        -ss PATHNAME              shell script with `main' procedure
        -sx PATHNAME              same as `-s', but print each expression
                                   as it is evaluated
        -setup-mode               prefer the current directory when locating extensions
    -R  -require-extension NAME   require extension and import before
                                   executing code
    -I  -include-path PATHNAME    add PATHNAME to include path
    --                            ignore all following options

EOF
) ) ;|  <--- for emacs font-lock

(define (print-banner)
  (newline)
  ;;UNUSED
  #;(when (and (tty-input?) (##sys#fudge 11))
    (let* ((t (string-copy +product+))
	   (len (string-length t))
	   (c (make-string len #\x08)))
      (do ((i (sub1 (* 2 len)) (sub1 i)))
	  ((zero? i))
	(let* ((p (abs (- i len)))
	       (o (string-ref t p)))
	  (string-set! t p #\@)
	  (print* t)
	  (string-set! t p o)
	  (let ((t0 (+ (current-milliseconds) 20)))
	    (let loop ()		; crude, but doesn't need srfi-18
	      (when (< (current-milliseconds) t0)
		(loop))))
	  (print* c) ) ) ) )
  (print +product+)
  (print +banner+ (chicken-version #t) "\n") )


;;; Reader for REPL history:

(set! ##sys#user-read-hook
  (let ([read-char read-char]
	[read read]
	[old-hook ##sys#user-read-hook] )
    (lambda (char port)
      (cond [(or (char=? #\) char) (char-whitespace? char))
	     `',(history-ref (fx- history-count 1)) ]
	    [else (old-hook char port)] ) ) ) )

(set! ##sys#sharp-number-hook
  (lambda (port n)
    `',(history-ref n) ) )


;;; Chop terminating separator from pathname:

(define (dirseparator? c)
  (or (char=? c #\\) (char=? c #\/)))

(define chop-separator 
  (let ([substring substring] )
    (lambda (str)
      (let* ((len (sub1 (##sys#size str)))
	     (c (string-ref str len)))
	(if (and (fx> len 0) (dirseparator? c))
	    (substring str 0 len)
	    str) ) ) ) )


;;; Find script in PATH (only used for Windows/DOS):

(define @ #f)

(define lookup-script-file 
  (let* ([buf (make-string 256)]
	 [_getcwd (foreign-lambda nonnull-c-string "_getcwd" scheme-pointer int)] )
    (define (addext name)
      (if (file-exists? name)
	  name
	  (let ([n2 (string-append name ".bat")])
	    (and (file-exists? n2) n2) ) ) )
    (define (string-index proc str1)
      (let ((len (##sys#size str1)))
	(let loop ((i 0))
	  (cond ((fx>= i len) #f)
		((proc (##core#inline "C_subchar" str1 i)) i)
		(else (loop (fx+ i 1))) ) ) ) )
    (lambda (name)
      (let ([path (get-environment-variable "PATH")])
	(and (> (##sys#size name) 0)
	     (cond [(dirseparator? (string-ref name 0)) (addext name)]
		   [(string-index dirseparator? name)
		    (and-let* ([p (_getcwd buf 256)])
		      (addext (string-append (chop-separator p) "/" name)) ) ]
		   [(addext name)]
		   [else
		    (let ([name2 (string-append "/" name)])
		      (let loop ([ps (string-split path ";")])
			(and (pair? ps)
			     (let ([name2 (string-append (chop-separator (##sys#slot ps 0)) name2)])
			       (or (addext name2)
				   (loop (##sys#slot ps 1)) ) ) ) ) ) ] ) ) ) ) ) )
				   

;;; REPL customization:

(define history-list (make-vector 32))
(define history-count 1)

(define history-add
  (let ([vector-resize vector-resize])
    (lambda (vals)
      (let ([x (if (null? vals) (##sys#void) (##sys#slot vals 0))]
	    [size (##sys#size history-list)] )
	(when (fx>= history-count size)
	  (set! history-list (vector-resize history-list (fx* 2 size))) )
	(vector-set! history-list history-count x)
	(set! history-count (fx+ history-count 1))
	x) ) ) )

(define (history-clear)
  (vector-fill! history-list (##sys#void)))

(define history-show
  (let ((newline newline))
    (lambda ()
      (do ((i 1 (fx+ i 1)))
	  ((>= i history-count))
	(printf "#~a: " i)
	(##sys#with-print-length-limit
	 80
	 (lambda ()
	   (##sys#print (vector-ref history-list i) #t ##sys#standard-output)))
	(newline)))))

(define (history-ref index)
  (let ([i (inexact->exact index)])
    (if (and (fx> i 0) (fx<= i history-count))
	(vector-ref history-list i) 
	(##sys#error "history entry index out of range" index) ) ) )

(repl-prompt
 (let ((sprintf sprintf))
   (lambda ()
     (sprintf "#;~A~A> "
       (let ((m (##sys#current-module)))
	 (if m
	     (sprintf "~a:" (##sys#module-name m))
	     ""))
       history-count))))

(define (tty-input?)
  (or (##sys#fudge 12) (##sys#tty-port? ##sys#standard-input)) )

(set! ##sys#break-on-error #f)

(set! ##sys#read-prompt-hook
  (let ([old ##sys#read-prompt-hook])
    (lambda ()
      (when (tty-input?) (old)) ) ) )

(define command-table '())

(define (toplevel-command name proc #!optional help)
  (##sys#check-symbol name 'toplevel-command)
  (when help (##sys#check-string help 'toplevel-command))
  (cond ((assq name command-table) =>
	 (lambda (a)
	   (set-cdr! a (list proc help)) ))
	(else
	 (set! command-table (cons (list name proc help) command-table))))
  (##sys#void))

(set! ##sys#repl-eval-hook
  (let ((eval eval)
	(load-noisily load-noisily)
	(read read)
	(read-line read-line)
	(length length)
	(display display)
	(write write)
	(string-split string-split)
	(printf printf)
	(expand expand)
	(pretty-print pretty-print)
	(integer? integer?)
	(values values) )
    (lambda (form)
      (cond ((eof-object? form) (exit))
	    ((and (pair? form)
		  (eq? 'unquote (##sys#slot form 0)) )
	     (let ((cmd (cadr form)))
	       (cond ((assq cmd command-table) =>
		      (lambda (p)
			((cadr p))
			(##sys#void) ) )
		     (else
		      ;;XXX use `toplevel-command' to define as many as possible of these
		      (case cmd
			((x)
			 (let ([x (read)])
			   (pretty-print (##sys#strip-syntax (expand x)))
			   (##sys#void) ) )
			((p)
			 (let* ([x (read)]
				[xe (eval x)] )
			   (pretty-print xe)
			   (##sys#void) ) )
			((d)
			 (let* ([x (read)]
				[xe (eval x)] )
			   (describe xe) ) )
			((du)
			 (let* ([x (read)]
				[xe (eval x)] )
			   (dump xe) ) )
			((dur)
			 (let* ([x (read)]
				[n (read)]
				[xe (eval x)] 
				[xn (eval n)] )
			   (dump xe xn) ) )
			((r) (report))
			((q) (exit))
			((l)
			 (let ((fns (string-split (read-line))))
			   (for-each load fns)
			   (##sys#void) ) )
			((ln) 
			 (let ((fns (string-split (read-line))))
			   (for-each (cut load-noisily <> printer: (lambda (x) (pretty-print x) (print* "==> "))) fns)
			   (##sys#void) ) )
			((t)
			 (let ((x (read)))
			   (receive rs (time (eval x))
			     (history-add rs)
			     (apply values rs) ) ) )
			((exn) 
			 (when ##sys#last-exception
			   (history-add (list ##sys#last-exception))
			   (describe ##sys#last-exception) ) )
			((e)
			 (let ((r (system
				   (string-append 
				    (or (editor-command) default-editor)
				    " " (read-line)))))
			   (if (not (zero? r))
			       (printf "editor returned with non-zero exit status ~a" r))))
			((ch)
			 (history-clear)
			 (##sys#void))
			((h)
			 (history-show)
			 (##sys#void))
			((c)
			 (show-frameinfo selected-frame)
			 (##sys#void))
			((f)
			 (select-frame (read))
			 (##sys#void))
			((g)
			 (copy-from-frame (read)))
			((s)
			 (let* ((str (read-line))
				(r (system str)) )
			   (history-add (list r))
			   r) )
			((?)
			 (display 
			  "Toplevel commands:

 ,?                Show this text
 ,p EXP            Pretty print evaluated expression EXP
 ,d EXP            Describe result of evaluated expression EXP
 ,du EXP           Dump data of expression EXP
 ,dur EXP N        Dump range
 ,q                Quit interpreter
 ,l FILENAME ...   Load one or more files
 ,ln FILENAME ...  Load one or more files and print result of each top-level expression
 ,r                Show system information
 ,h                Show history of expression results
 ,ch               Clear history of expression results
 ,e FILENAME       Run external editor
 ,s TEXT ...       Execute shell-command
 ,exn              Describe last exception
 ,c                Show call-chain of most recent error
 ,f N              Select frame N
 ,g NAME           Get variable NAME from current frame
 ,t EXP            Evaluate form and print elapsed time
 ,x EXP            Pretty print expanded expression EXP\n")
			 (for-each
			  (lambda (a) 
			    (let ((help (caddr a)))
			      (if help
				  (print #\space help)
				  (print " ," (car a)) ) ) )
			  command-table)
			 (##sys#void) )
			(else
			 (printf "undefined toplevel command ~s - enter `,?' for help~%" form) 
			 (##sys#void) ) ) ) ) ) )
	    (else
	     (receive rs (eval form)
	       (history-add rs)
	       (apply values rs) ) ) ) ) ) )


;;; Builtin toplevel commands:

(toplevel-command
 'm 
 (let ((printf printf))
   (lambda ()
     (let ((name (read)))
       (cond ((not name)
	      (##sys#current-module #f)
	      (printf "; resetting current module to toplevel~%"))
	     ((string? name)
	      (set! name (##sys#string->symbol name)))
	     ((not (symbol? name))
	      (printf "invalid module name `~a'~%" name))
	     ((##sys#find-module name #f) =>
	      (lambda (m)
		(##sys#current-module m)
		(printf "; switching current module to `~a'~%" name)))
	     (else
	      (printf "undefined module `~a'~%" name))))))
 ",m MODULE         switch to module with name `MODULE'")


;;; Parse options from string:

(define (parse-option-string str)
  (let ([ins (open-input-string str)])
    (map (lambda (o)
	   (if (string? o)
	       o
	       (let ([os (open-output-string)])
		 (write o os)
		 (get-output-string os) ) ) )
	 (handle-exceptions ex (##sys#error "invalid option syntax" str)
	   (do ([x (read ins) (read ins)]
		[xs '() (cons x xs)] )
	       ((eof-object? x) (reverse xs)) ) ) ) ) )


;;; Print status information:

(define report
  (let ((printf printf)
	(chop chop)
	(sort sort)
	(with-output-to-port with-output-to-port)
	(current-output-port current-output-port) 
	(argv argv)
	(prefix
	 (or (get-environment-variable "CHICKEN_PREFIX")
	     (foreign-value "C_INSTALL_PREFIX" c-string) ) ))
    (lambda port
      (with-output-to-port (if (pair? port) (car port) (current-output-port))
	(lambda ()
	  (gc)
	  (let ([sinfo (##sys#symbol-table-info)]
		[minfo (memory-statistics)] )
	    (define (shorten n) (/ (truncate (* n 100)) 100))
	    (printf "Features:~%~%")
	    (let ((fs (sort (map keyword->string ##sys#features) string<?))
		  (c 0))
	      (for-each
	       (lambda (f)
		 (printf "  ~a" f)
		 (let* ((len (string-length f))
			(pad (- 16 len)))
		   (set! c (add1 c))
		   (when (<= pad 0)
		     (set! c (add1 c))
		     (set! pad (+ pad 18)))
		   (cond ((>= c 3)
			  (display "\n")
			  (set! c 0))
			 (else 
			  (display (make-string pad #\space))))))
	       fs))
	    (printf "~%~%~
                   Machine type:    \t~A ~A~%~
                   Software type:   \t~A~%~
                   Software version:\t~A~%~
                   Build platform:  \t~A~%~
                   Installation prefix:\t~A~%~
                   Extension path:  \t~A~%~
                   Include path:    \t~A~%~
                   Symbol-table load:\t~S~%  ~
                     Avg bucket length:\t~S~%  ~
                     Total symbol count:\t~S~%~
                   Memory:\theap size is ~S bytes~A with ~S bytes currently in use~%~  
                     nursery size is ~S bytes, stack grows ~A~%~
                   Command line:    \t~S~%"
		    (machine-type)
		    (if (##sys#fudge 3) "(64-bit)" "")
		    (software-type)
		    (software-version)
		    (build-platform)
		    prefix
		    (repository-path)
		    ##sys#include-pathnames
		    (shorten (vector-ref sinfo 0))
		    (shorten (vector-ref sinfo 1))
		    (vector-ref sinfo 2)
		    (vector-ref minfo 0)
		    (if (##sys#fudge 17) " (fixed)" "")
		    (vector-ref minfo 1)
		    (vector-ref minfo 2)
		    (if (= 1 (##sys#fudge 18)) "downward" "upward")
		    (argv))
	    (##sys#write-char-0 #\newline ##sys#standard-output)
	    (when (##sys#fudge 14) (display "interrupts are enabled\n"))
	    (when (##sys#fudge 15) (display "symbol gc is enabled\n")) 
	    (##core#undefined) ) ) ) ) ) )


;;; Describe & dump:

(define bytevector-data
  '((u8vector "vector of unsigned bytes" u8vector-length u8vector-ref)
    (s8vector "vector of signed bytes" s8vector-length s8vector-ref)
    (u16vector "vector of unsigned 16-bit words" u16vector-length u16vector-ref)
    (s16vector "vector of signed 16-bit words" s16vector-length s16vector-ref)
    (u32vector "vector of unsigned 32-bit words" u32vector-length u32vector-ref)
    (s32vector "vector of signed 32-bit words" s32vector-length s32vector-ref)
    (f32vector "vector of 32-bit floats" f32vector-length f32vector-ref)
    (f64vector "vector of 64-bit floats" f64vector-length f64vector-ref) ) )

(define (circular-list? x)
  (let lp ((x x) (lag x))
    (and (pair? x)
	 (let ((x (cdr x)))
	   (and (pair? x)
		(let ((x   (cdr x))
		      (lag (cdr lag)))
		  (or (eq? x lag) (lp x lag))))))))

(define (improper-pairs? x)
  (let lp ((x x))
    (if (not (pair? x)) #f
       (or (eq? x (car x))
           (lp (cdr x))))))

(define-constant max-describe-lines 40)

(define describer-table (make-vector 37 '()))

(define describe
  (let ([sprintf sprintf]
	[printf printf] 
	[fprintf fprintf]
	[length length]
	[list-ref list-ref]
	[string-ref string-ref])
    (lambda (x #!optional (out ##sys#standard-output))
      (define (descseq name plen pref start)
	(let ((len (fx- (plen x) start)))
	  (when name (fprintf out "~A of length ~S~%" name len))
	  (let loop1 ((i 0))
	    (cond ((fx>= i len))
		  ((fx>= i max-describe-lines)
		   (fprintf out "~% (~A elements not displayed)~%" (fx- len i)) )
		  (else
		   (let ((v (pref x (fx+ start i))))
		     (let loop2 ((n 1) (j (fx+ i (fx+ start 1))))
		       (cond ((fx>= j len)
			      (fprintf out " ~S: ~S" i v)
			      (if (fx> n 1)
				  (fprintf out "\t(followed by ~A identical instance~a)~% ...~%" 
					   (fx- n 1)
					   (if (eq? n 2) "" "s"))
				  (newline out) )
			      (loop1 (fx+ i n)) )
			     ((eq? v (pref x j)) (loop2 (fx+ n 1) (fx+ j 1)))
			     (else (loop2 n len)) ) ) ) ) ) ) ) )
      (when (##sys#permanent? x)
	(fprintf out "statically allocated (0x~X) " (##sys#block-address x)) )
      (cond [(char? x)
	     (let ([code (char->integer x)])
	       (fprintf out "character ~S, code: ~S, #x~X, #o~O~%" x code code code) ) ]
	    [(eq? x #t) (fprintf out "boolean true~%")]
	    [(eq? x #f) (fprintf out "boolean false~%")]
	    [(null? x) (fprintf out "empty list~%")]
	    [(eof-object? x) (fprintf out "end-of-file object~%")]
	    [(eq? (##sys#void) x) (fprintf out "unspecified object~%")]
	    [(fixnum? x)
	     (fprintf out "exact integer ~S~%  #x~X~%  #o~O~%  #b~B" x x x x)
	     (let ([code (integer->char x)])
	       (when (fx< x #x10000) (fprintf out ", character ~S" code)) )
	     (##sys#write-char-0 #\newline ##sys#standard-output) ]
	    [(eq? x (##sys#slot '##sys#arbitrary-unbound-symbol 0))
	     (fprintf out "unbound value~%") ]
	    [(flonum? x) (fprintf out "inexact number ~S~%" x)]
	    [(number? x) (fprintf out "number ~S~%" x)]
	    [(string? x) (descseq "string" ##sys#size string-ref 0)]
	    [(vector? x) (descseq "vector" ##sys#size ##sys#slot 0)]
	    ((keyword? x)
	     (fprintf out "keyword symbol with name ~s~%" 
	       (##sys#symbol->string x)))
	    [(symbol? x)
	     (unless (##sys#symbol-has-toplevel-binding? x)
	       (display "unbound " out))
	     (let ((q (##sys#qualified-symbol? x)))
	       (fprintf out "~a~asymbol with name ~S~%"
		 (if (##sys#interned-symbol? x) "" "uninterned ")
		 (if q "qualified " "")
		 (if q 
		     (##sys#symbol->qualified-string x)
		     (##sys#symbol->string x))))
	     (let ((plist (##sys#slot x 2)))
	       (unless (null? plist)
		 (display "  \nproperties:\n\n" out)
		 (do ((plist plist (cddr plist)))
		     ((null? plist))
		   (fprintf out "  ~s\t" (car plist))
		   (##sys#with-print-length-limit
		    1000
		    (lambda ()
		      (write (cadr plist) out) ) )
		   (newline out) ) ) ) ]
	    [(or (circular-list? x) (improper-pairs? x))
	     (fprintf out "circular structure: ")
	     (let loop-print ((x x)
                              (cdr-refs (list x)))
               (cond ((or (atom? x)
                          (null? x)) (printf "eol~%"))
                     ((memq (car x) cdr-refs)
                      (fprintf out "(circle)~%" ))
		     ((not (memq (car x) cdr-refs))
		      (fprintf out "~S -> " (car x))
		      (loop-print (cdr x) (cons (car x)  cdr-refs) ))))]
	    [(list? x) (descseq "list" length list-ref 0)]
	    [(pair? x) (fprintf out "pair with car ~S~%and cdr ~S~%" (car x) (cdr x))]
	    [(procedure? x)
	     (let ([len (##sys#size x)])
	       (descseq 
		(sprintf "procedure with code pointer ~X" (##sys#peek-unsigned-integer x 0))
		##sys#size ##sys#slot 1) ) ]
	    [(port? x)
	     (fprintf out
		      "~A port of type ~A with name ~S and file pointer ~X~%"
		      (if (##sys#slot x 1) "input" "output")
		      (##sys#slot x 7)
		      (##sys#slot x 3)
		      (##sys#peek-unsigned-integer x 0) ) ]
	    [(##sys#locative? x)
	     (fprintf out "locative~%  pointer ~X~%  index ~A~%  type ~A~%"
		      (##sys#peek-unsigned-integer x 0)
		      (##sys#slot x 1)
		      (case (##sys#slot x 2) 
			[(0) "slot"]
			[(1) "char"]
			[(2) "u8vector"]
			[(3) "s8vector"]
			[(4) "u16vector"]
			[(5) "s16vector"]
			[(6) "u32vector"]
			[(7) "s32vector"]
			[(8) "f32vector"]
			[(9) "f64vector"] ) ) ]
	    [(##sys#pointer? x) (fprintf out "machine pointer ~X~%" (##sys#peek-unsigned-integer x 0))]
	    [(##sys#bytevector? x)
	     (let ([len (##sys#size x)])
	       (fprintf out "blob of size ~S:~%" len)
	       (hexdump x len ##sys#byte out) ) ]
	    [(##core#inline "C_lambdainfop" x)
	     (fprintf out "lambda information: ~s~%" (##sys#lambda-info->string x)) ]
	    [(##sys#structure? x 'hash-table)
	     (let ((n (##sys#slot x 2)))
	       (fprintf out "hash-table with ~S element~a~%  comparison procedure: ~A~%"
			n (if (fx= n 1) "" "s")  (##sys#slot x 3)) )
	     (fprintf out "  hash function: ~a~%" (##sys#slot x 4))
	     ;; this copies code out of srfi-69.scm, but we don't want to depend on it
	     (let* ((vec (##sys#slot x 1))
		    (len (##sys#size vec)) )
	       (do ((i 0 (fx+ i 1)) )
		   ((fx>= i len))
		 (for-each
		  (lambda (bucket)
		    (fprintf out " ~S\t-> ~S~%"
		      (##sys#slot bucket 0) (##sys#slot bucket 1)) )
		  (##sys#slot vec i)) ) ) ]
	    [(##sys#structure? x 'condition)
	     (fprintf out "condition: ~s~%" (##sys#slot x 1))
	     (for-each
	      (lambda (k)
		(fprintf out " ~s~%" k)
		(let loop ((props (##sys#slot x 2)))
		  (unless (null? props)
		    (when (eq? k (caar props))
		      (##sys#with-print-length-limit
		       100
		       (lambda ()
			 (fprintf out "\t~s: ~s" (cdar props) (cadr props)) ))
		      (newline out))
		    (loop (cddr props)) ) ) )
	      (##sys#slot x 1) ) ]
	    [(##sys#generic-structure? x)
	     (let ([st (##sys#slot x 0)])
	       (cond ((##sys#hash-table-ref describer-table st) => (cut <> x out))
		     ((assq st bytevector-data) =>
		      (lambda (data)
			(apply descseq (append (map eval (cdr data)) (list 0)))) )
		     (else
		      (fprintf out "structure of type `~S':~%" (##sys#slot x 0))
		      (descseq #f ##sys#size ##sys#slot 1) ) ) ) ]
	    [else (fprintf out "unknown object~%")] )
      (##sys#void) ) ) )

(define (set-describer! tag proc)
  (##sys#check-symbol tag 'symbol 'set-describer!)
  (##sys#hash-table-set! describer-table tag proc) )


;;; Display hexdump:

(define dump
  (lambda (x . len-out)
    (let-optionals len-out
	([len #f]
	 [out ##sys#standard-output] )
      (define (bestlen n) (if len (min len n) n))
      (cond [(##sys#immediate? x) (##sys#error 'dump "cannot dump immediate object" x)]
	    [(##sys#bytevector? x) (hexdump x (bestlen (##sys#size x)) ##sys#byte out)]
	    [(string? x) (hexdump x (bestlen (##sys#size x)) ##sys#byte out)]
	    [(and (not (##sys#immediate? x)) (##sys#pointer? x))
	     (hexdump x 32 ##sys#peek-byte out) ]
	    [(and (##sys#generic-structure? x) (assq (##sys#slot x 0) bytevector-data))
	     (let ([bv (##sys#slot x 1)])
	       (hexdump bv (bestlen (##sys#size bv)) ##sys#byte out) ) ]
	    [else (##sys#error 'dump "cannot dump object" x)] ) ) ) )

(define hexdump
  (let ([display display]
	[string-append string-append]
	[make-string make-string]
	[write-char write-char] )
    (lambda (bv len ref out)

      (define (justify n m base lead)
	(let* ([s (number->string n base)]
	       [len (##sys#size s)] )
	  (if (fx< len m)
	      (string-append (make-string (fx- m len) lead) s)
	      s) ) )

      (do ([a 0 (fx+ a 16)])
	  ((fx>= a len))
	(display (justify a 4 10 #\space) out)
	(write-char #\: out)
	(do ([j 0 (fx+ j 1)]
	     [a a (fx+ a 1)] )
	    ((or (fx>= j 16) (fx>= a len))
	     (when (fx>= a len)
	       (let ((o (fxmod len 16)))
		 (unless (fx= o 0)
		   (do ((k (fx- 16 o) (fx- k 1)))
		       ((fx= k 0))
		     (display "   " out) ) ) ) ) ) 
	  (write-char #\space out)
	  (display (justify (ref bv a) 2 16 #\0) out) )
	(write-char #\space out)
	(do ([j 0 (fx+ j 1)]
	     [a a (fx+ a 1)] )
	    ((or (fx>= j 16) (fx>= a len)))
	  (let ([c (ref bv a)])
	    (if (and (fx>= c 32) (fx< c 128))
		(write-char (integer->char c) out)
		(write-char #\. out) ) ) ) 
	(write-char #\newline out) ) ) ) )


;;; Frame-info operations:

(define show-frameinfo
  (let ((write-char write-char)
	(newline newline)
	(display display))
    (lambda (fn)
      (define (prin1 x)
	(##sys#with-print-length-limit
	 100
	 (lambda ()
	   (##sys#print x #t ##sys#standard-output))))
      (let* ((ct (or ##sys#repl-recent-call-chain '()))
	     (len (length ct)))
	(set! selected-frame 
	  (or (and (memq fn ct) fn)
	      (and (fx> len 0)
		   (list-ref ct (fx- len 1)))))
	(do ((ct ct (cdr ct))
	     (i (fx- len 1) (fx- i 1)))
	    ((null? ct))
	  (let* ((info (car ct))
		 (here (eq? selected-frame info))
		 (form (##sys#slot info 1)) ; cooked1 (expr/form)
		 (data (##sys#slot info 2)) ; cooked2 (cntr/frameinfo)
		 (finfo (##sys#structure? data 'frameinfo))
		 (cntr (if finfo (##sys#slot data 1) data))) ; cntr
	    (printf "~a~a:~a\t~a\t  " 
	      (if here #\* #\space)
	      i
	      (if (and finfo (pair? (##sys#slot data 2))) "[]" "  ") ; e
	      (##sys#slot info 0))	; raw
	    (when cntr (printf "[~a] " cntr))
	    (when form (prin1 form))
	    (newline)
	    (when (and here finfo)
	      (for-each
	       (lambda (e v)
		 (unless (null? e)
		   (display "  ---\n")
		   (do ((i 0 (fx+ i 1))
			(be e (cdr be)))
		       ((null? be))
		     (printf "  ~s:\t  " (car be))
		     (prin1 (##sys#slot v i))
		     (newline))))
	       (##sys#slot data 2)	   ; e
	       (##sys#slot data 3)))))))))	   ; v
	  
(define select-frame
  (let ((display display))
    (lambda (n)
      (cond ((or (not (number? n))
		 (not ##sys#repl-recent-call-chain)
		 (fx< n 0)
		 (fx>= n (length ##sys#repl-recent-call-chain)))
	     (display "no such frame\n"))
	    (else
	     (set! selected-frame
	       (list-ref 
		##sys#repl-recent-call-chain
		(fx- (length ##sys#repl-recent-call-chain) (fx+ n 1))))
	     (show-frameinfo selected-frame))))))

(define copy-from-frame
  (let ((display display)
	(newline newline)
	(call/cc call/cc))
    (lambda (name)
      (let* ((ct (or ##sys#repl-recent-call-chain '()))
	     (len (length ct))
	     (name 
	      (cond ((symbol? name) (##sys#slot name 1)) ; name
		    ((string? name) name)
		    (else 
		     (display "string or symbol required for `,g'\n")
		     #f))))
	(define (compare sym)
	  (let ((str (##sys#slot sym 1))) ; name
	    (string=?
	     name
	     (substring str 0 (min (string-length name) (string-length str))))))
	(if name
	    (call/cc
	     (lambda (return)
	       (define (fail msg)
		 (display msg)
		 (newline)
		 (return (##sys#void)))
	       (do ((ct ct (cdr ct)))
		   ((null? ct) (fail "no environment in frame")) 
		 ;;XXX this should be refactored as it duplicates the code above
		 (let* ((info (car ct))
			(here (eq? selected-frame info))
			(data (##sys#slot info 2)) ; cooked2 (cntr/frameinfo)
			(finfo (##sys#structure? data 'frameinfo)))
		   (when (and here finfo)
		     (for-each
		      (lambda (e v)
			(do ((i 0 (fx+ i 1))
			     (be e (cdr be)))
			    ((null? be))
			  (when (compare (car be))
			    (display "; getting ")
			    (display (car be))
			    (newline)
			    (history-add (list (##sys#slot v i)))
			    (return (##sys#slot v i)))))
		      (##sys#slot data 2)	; e
		      (##sys#slot data 3))	; v
		     (fail (##sys#string-append "no such variable: " name)))))))
	    (##sys#void))))))


;;; Start interpreting:

(define (del x lst tst)
  (let loop ([lst lst])
    (if (null? lst)
	'()
	(let ([y (car lst)])
	  (if (tst x y)
	      (cdr lst)
	      (cons y (loop (cdr lst))) ) ) ) ) )

(define (deldups lis . maybe-=)
  (let ((elt= (optional maybe-= equal?)))
    (let recur ((lis lis))
      (if (null? lis) lis
	  (let* ((x (car lis))
		 (tail (cdr lis))
		 (new-tail (recur (del x tail elt=))))
	    (if (eq? tail new-tail) lis (cons x new-tail)))))))

(define (member* keys set)
  (let loop ((set set))
    (and (pair? set)
	 (let find ((ks keys))
	   (cond ((null? ks) (loop (cdr set)))
		 ((equal? (car ks) (car set)) set)
		 (else (find (cdr ks))) ) ) ) ) )

(define-constant short-options 
  '(#\k #\s #\v #\h #\D #\e #\i #\R #\b #\n #\q #\w #\- #\I #\p #\P) )

(define-constant long-options
  '("-ss" "-sx" "-script" "-version" "-help" "--help" "-feature" "-no-feature" "-eval"
    "-case-insensitive" "-keyword-style" "-no-parentheses-synonyms" "-no-symbol-escape"
    "-r5rs-syntax" "-setup-mode"
    "-require-extension" "-batch" "-quiet" "-no-warnings" "-no-init" 
    "-include-path" "-release" "-print" "-pretty-print" "--") )

(define (canonicalize-args args)
  (let loop ((args args))
    (if (null? args)
	'()
	(let ((x (car args)))
	  (cond ((member x '("-s" "-ss" "-script" "-sx" "--")) args)
                ((and (fx> (##sys#size x) 2)
                       (char=? #\- (##core#inline "C_subchar" x 0))
                       (not (member x long-options)) )
                 (if (char=? #\: (##core#inline "C_subchar" x 1))
                     (loop (cdr args))
                     (let ((cs (string->list (substring x 1))))
                       (if (findall cs short-options)
                           (append (map (cut string #\- <>) cs) (loop (cdr args)))
                           (##sys#error "invalid option" x) ) ) ) )
	        (else (cons x (loop (cdr args)))))))))

(define (findall chars clist)
  (let loop ((chars chars))
    (or (null? chars)
	(and (memq (car chars) clist)
	     (loop (cdr chars))))))

(define-constant simple-options
  '("--" "-b" "-batch" "-q" "-quiet" "-n" "-no-init" "-w" "-no-warnings" 
    "-i" "-case-insensitive"
    "-no-parentheses-synonyms" "-no-symbol-escape" "-r5rs-syntax" "-setup-mode"
    ; Not "simple" but processed early
    "-ss" "-sx" "-s" "-script") )

(define-constant complex-options
  '("-D" "-feature" "-I" "-include-path" "-K" "-keyword-style" "-no-feature") )

(define (run)
  (let* ([extraopts (parse-option-string (or (get-environment-variable "CSI_OPTIONS") ""))]
	 [args (canonicalize-args (command-line-arguments))]
	 ; Check for these before 'args' is updated by any 'extraopts'
	 [kwstyle (member* '("-K" "-keyword-style") args)]
	 [script (member* '("-ss" "-sx" "-s" "-script") args)])
    (cond [script
	   (when (or (not (pair? (cdr script)))
		     (zero? (string-length (cadr script)))
		     (char=? #\- (string-ref (cadr script) 0)) )
	     (##sys#error "missing or invalid script argument"))
	   (program-name (cadr script))
	   (command-line-arguments (cddr script))
	   (register-feature! 'script)	; DEPRECATED
	   (register-feature! 'chicken-script)
	   (set-cdr! (cdr script) '()) 
	   (when ##sys#windows-platform
	     (and-let* ((sname (lookup-script-file (cadr script))))
	       (set-car! (cdr script) sname) ) ) ]
	  [else
	   (set! args (append (canonicalize-args extraopts) args))
	   (and-let* ([p (member "--" args)])
	     (set-cdr! p '()) ) ] )
    (let* ([eval? (member* '("-e" "-p" "-P" "-eval" "-print" "-pretty-print") args)]
	   [batch (or script (member* '("-b" "-batch") args) eval?)]
	   [quietflag (member* '("-q" "-quiet") args)]
	   [quiet (or script quietflag eval?)]
	   [ipath (map chop-separator 
		       (string-split 
			(or (get-environment-variable "CHICKEN_INCLUDE_PATH") "") 
			";"))] )      
      (define (collect-options opt)
	(let loop ([opts args])
	  (cond [(member opt opts) 
		 => (lambda (p)
		      (if (null? (cdr p))
			  (##sys#error "missing argument to command-line option" opt)
			  (cons (cadr p) (loop (cddr p)))) ) ]
		[else '()] ) ) )
      (define (loadinit)
	(let ([fn (##sys#string-append "./" init-file)])
	  (if (file-exists? fn)
	      (load fn)
	      (let* ([prefix (chop-separator (or (get-environment-variable "HOME") "."))]
		     [fn (string-append prefix "/" init-file)] )
		(when (file-exists? fn) 
		  (load fn) ) ) ) ) )
      (define (evalstring str #!optional (rec (lambda _ (void))))
	(let ((in (open-input-string str)))
	  (do ([x (read in) (read in)])
	      ((eof-object? x))
	    (rec (receive (eval x))) ) ) )
      (when (member* '("-h" "-help" "--help") args)
	(print-usage)
	(exit 0) )
      (when (member* '("-v" "-version") args)
	(print-banner)
	(exit 0) )
      (when (member "-setup-mode" args)
	(set! ##sys#setup-mode #t))
      (when (member "-release" args)
	(print (chicken-version))
	(exit 0) )
      (when (member* '("-w" "-no-warnings") args)
	(unless quiet (display "Warnings are disabled\n"))
	(set! ##sys#warnings-enabled #f) )
      (unless quiet
	(load-verbose #t)
	(print-banner) )
      (when (member* '("-i" "-case-insensitive") args)
	(unless quiet (display "Identifiers and symbols are case insensitive\n"))
	(register-feature! 'case-insensitive)
	(case-sensitive #f) )
      (for-each register-feature! (collect-options "-feature"))
      (for-each register-feature! (collect-options "-D"))
      (for-each unregister-feature! (collect-options "-no-feature"))
      (set! ##sys#include-pathnames 
	(deldups
	 (append (map chop-separator (collect-options "-include-path"))
		 (map chop-separator (collect-options "-I"))
		 ##sys#include-pathnames
		 ipath)
	 string=?) )
      (when kwstyle
	(cond [(not (pair? (cdr kwstyle)))
	       (##sys#error "missing argument to `-keyword-style' option") ]
	      [(string=? "prefix" (cadr kwstyle))
	       (keyword-style #:prefix) ]
	      [(string=? "none" (cadr kwstyle))
	       (keyword-style #:none) ]
	      [(string=? "suffix" (cadr kwstyle))
	       (keyword-style #:suffix) ] ) )
      (when (member* '("-no-parentheses-synonyms") args)
	(unless quiet (display "Disabled support for parentheses synonyms\n"))
        (parentheses-synonyms #f) )
      (when (member* '("-no-symbol-escape") args)
	(unless quiet (display "Disabled support for escaped symbols\n"))
	(symbol-escape #f) )
      (when (member* '("-r5rs-syntax") args)
	(unless quiet (display "Disabled the Chicken extensions to R5RS syntax\n"))
	(case-sensitive #f)
	(keyword-style #:none)
	(parentheses-synonyms #f)
	(symbol-escape #f) )
      (unless (or (member* '("-n" "-no-init") args) script eval?) (loadinit))
      (when batch 
	(set! ##sys#notices-enabled #f))
      (do ([args args (cdr args)])
	  ((null? args)
	   (unless batch 
	     (repl)
	     (##sys#write-char-0 #\newline ##sys#standard-output) ) )
	(let* ((arg (car args)))
	  (cond ((member arg simple-options))
		((member arg complex-options)
		 (set! args (cdr args)) )
		((or (string=? "-R" arg) (string=? "-require-extension" arg))
		 (eval `(##core#require-extension (,(string->symbol (cadr args))) #t))
		 (set! args (cdr args)) )
		((or (string=? "-e" arg) (string=? "-eval" arg))
		 (evalstring (cadr args))
		 (set! args (cdr args)) )
		((or (string=? "-p" arg) (string=? "-print" arg))
		 (evalstring (cadr args) (cut for-each print <...>))
		 (set! args (cdr args)) )
		((or (string=? "-P" arg) (string=? "-pretty-print" arg))
		 (evalstring (cadr args) (cut for-each pretty-print <...>) )
		 (set! args (cdr args)) )
		(else
		 (let ((scr (and script (car script))))
		   (##sys#load 
		    arg 
		    (and (equal? "-sx" scr)
			 (lambda (x)
			   (let* ((str (with-output-to-string (cut pretty-print x)))
				  (len (string-length str)))
			     (flush-output ##sys#standard-output)
			     (display "\n; " ##sys#standard-error)
			     (do ((i 0 (fx+ i 1)))
				 ((fx>= i len))
			       (let ((c (string-ref str i)))
				 (write-char c ##sys#standard-error)
				 (when (char=? #\newline c)
				   (display "; " ##sys#standard-error))))
			     (newline ##sys#standard-error)
			     (eval x))))
		    #f)
		   (when (equal? "-ss" scr)
		     (call-with-values (cut main (command-line-arguments))
		       (lambda results
			 (exit
			  (if (and (pair? results) (fixnum? (car results)))
			      (car results)
			      0) ) ) ) ) ) ) ) ) ) ) ) )

(run)