;;;;
;;;; The DESCRIBE method (partly stolen fom Elk lib)
;;;;
;;;; Copyright © 1993-1999 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
;;;; 
;;;; Permission to use, copy, modify, distribute,and license this
;;;; software and its documentation for any purpose is hereby granted,
;;;; provided that existing copyright notices are retained in all
;;;; copies and that this notice is included verbatim in any
;;;; distributions.  No written agreement, license, or royalty fee is
;;;; required for any of the authorized uses.
;;;; This software is provided ``AS IS'' without express or implied
;;;; warranty.
;;;;
;;;;           Author: Erick Gallesio [eg@unice.fr]
;;;;    Creation date: 21-Mar-1993 14:33
;;;; Last file update:  3-Sep-1999 20:05 (eg)
;;;;

(require "stklos")

(select-module STklos)			;; This file belongs to STklos module
(export describe)			;; Export the describe generic function

;;;
;;; describe for simple objects
;;;
(define-method describe ((x <top>))
  (format #t "~W is " x)
  (cond
     ((integer? x)      (format #t "an integer"))
     ((real?    x)      (format #t "a real"))
     ((null?	x)      (format #t "an empty list"))
     ((boolean?	x)      (format #t "a boolean value (~s)" (if x 'true 'false)))
     ((char?	x)      (format #t "a character, ascii value is ~s" 
				(char->integer x)))
     ((symbol?	x)      (format #t "a symbol"))
     ((pair?	x)	(format #t "a list"))
     ((string?	x)	(if (eqv? x "")
			    (format #t "an empty string")
			    (format #t "a string of length ~s" (string-length x))))
     ((vector?  x)   	(if (eqv? x '#())
			    (format #t "an empty vector")
			    (format #t "a vector of length ~s" (vector-length x))))
     ((procedure? x)	(format #t "a procedure"))
     ((environment? x)	(format #t "an environment"))
     ((eof-object? x)	(format #t "the end-of-file object"))
     (else	     	(format #t "an an instance of class ~A" 
				(class-name (class-of x)))))
  (format #t ".~%"))


;;;
;;; describe for STklos instances
;;;
(define-method describe ((x <object>))
  (next-method)
  ;; print all the instance slots
  (format #t "Slots are: ~%")
  (for-each (lambda (slot)
	      (let ((name (slot-definition-name slot)))
		(format #t "     ~S = ~A~%" name
					    (if (slot-bound? x name) 
						(format #f "~W" (slot-ref x name))
						"#[unbound]"))))
       (class-slots (class-of x)))
  (make-undefined))

;;;
;;; Describe for classes
;;;
(define-method describe ((x <class>))
  (format #t "~S is a class. It's an instance of ~A~%." 
	  (class-name x) (class-name (class-of x)))
  
  ;; Super classes 
  (format #t "Superclasses are:~%")
  (for-each (lambda (class) (format #t "    ~A~%" (class-name class)))
       (class-direct-supers x))

  ;; Direct slots
  (let ((slots (class-direct-slots x)))
    (if (null? slots) 
	(format #t "(No direct slot)~%")
	(begin
	  (format #t "Directs slots are:~%")
	  (for-each (lambda (s) 
		      (format #t "    ~A~%" (slot-definition-name s)))
		    slots))))

 
  ;; Direct subclasses
  (let ((classes (class-direct-subclasses x)))
    (if (null? classes)
	(format #t "(No direct subclass)~%")
	(begin
	  (format #t "Directs subclasses are:~%") 
	  (for-each (lambda (s) 
		      (format #t "    ~A~%" (class-name s)))
		    classes))))

  ;; CPL
  (format #t "Class Precedence List is:~%")
  (for-each (lambda (s) (format #t "    ~A~%" (class-name s))) 
	    (class-precedence-list x))

  ;; Direct Methods
  (let ((methods (class-direct-methods x)))
    (if (null? methods)
	(format #t "(No direct method)~%")
	(begin
	  (format #t "Class direct methods are:~%")
	  (for-each describe methods))))

;  (format #t "~%Field Initializers ~%    ")
;  (write (slot-ref x 'initializers)) (newline)

;  (format #t "~%Getters and Setters~%    ")
;  (write (slot-ref x 'getters-n-setters)) (newline)
)

;;;
;;; Describe for generic functions
;;;
(define-method describe ((x <generic>))
  (let ((name    (generic-function-name x))
	(methods (generic-function-methods x)))
    ;; Title
    (format #t "~S is a generic function. It's an instance of ~A.~%" 
	    name (class-name (class-of x)))
    ;; Methods
    (if (null? methods)
	(format #t "(No method defined for ~S)~%" name)
	(begin
	  (format #t "Methods defined for ~S~%" name)
	  (for-each (lambda (x) (describe x #t)) methods)))))

;;;
;;; Describe for methods
;;;
(define-method describe ((x <method>) . omit-generic)
  (letrec ((print-args (lambda (args)
			 ;; take care of dotted arg lists
			 (cond ((null? args) (newline))
			       ((pair? args) (display #\space)
					     (display (class-name (car args)))
					     (print-args (cdr args)))
			       (else	     (display #\space)
					     (display (class-name args))
					     (newline))))))

    ;; Title
    (format #t "    Method ~A~%" x)
    
    ;; Associated generic
    (when (null? omit-generic)
      (let ((gf (method-generic-function x)))
	(if gf
	    (format #t "\t     Generic: ~A~%" (generic-function-name gf))
	    (format #t "\t(No generic)~%"))))

    ;; GF specializers
    (format #t "\tSpecializers:")
    (print-args (method-specializers x))))

(provide "describe")