;;; escm-context.el --- 

;; Copyright (C) 2008  Free Software Foundation, Inc.

;; Author: Zaurus User <zaurus@localhost.localdomain>
;; Keywords: 

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; 

;;; Code:
(require 'escm-base)
(require 'escm-env)

(escm-cbos::define-class
 (escm-context escm-object t)
 (objdic :copy)         ;; created objects.
 (env    :copy)  ;; environment of current context.
 (vm     :copy)  ;; virtual machine.
 (tail?  :copy)  ;; non nil if current context is terminal.
 (func?  :copy))

(defconst escm-context::gensym::counter 0)
(defsubst escm-context::gensym ()
  (intern
   (format "escm-context::gensym::symbol::%s"
	   (setq escm-context::gensym::counter
		 (1+ escm-context::gensym::counter)))))

(defsubst escm-context::new (env &optional vm objdic)
  (escm-context::set-objdic
   (escm-context::set-vm
    (escm-context::set-env
     (create-escm-context)
     env)
    vm)
   (or objdic (list nil))))


(defsubst escm-context::push (self &optional syms)
  (escm-context::new
   (escm-dynamic-env::new (escm-context::get-env self) syms)
   (escm-context::get-vm self)
   (escm-context::get-objdic self)))

(defsubst escm-context::define (self obj)
  (let ((sym (escm-context::gensym))
	(dic (escm-context::get-objdic self)))
    (set-car dic (cons (cons sym val)
		       (car dic)))
    sym))

(defsubst escm-context::elize (self)
  `(let*
       ,(mapcar
	 (lambda (step)
	   (list (car step)
		 (escm-object::to-source (cdr spec))))
	 (reverse (car
		   (escm-context::get-objdic
		    self))))))

;;;
(escm-cbos::define-class (escm-reference escm-object) (sym))
(defsubst escm-reference::new (sym)
  (let ((new (create-escm-reference)))
    (escm-reference::set-sym new sym)
    new))

(escm-cbos::define-method nil escm-object::elize (context self)
  (cond
   ((consp self) (list 'quote self))
   (t self)))

(escm-cbos::define-method nil escm-object::value (context self) self)

(escm-cbos::define-method escm-reference escm-object::elize (context self)
  (escm-reference::get-sym self))

(escm-cbos::define-method escm-reference escm-object::value (context self) self
  (escm-context::ref context (escm-reference::get-sym self)))

(escm-cbos::define-method escm-env escm-object::elize (context self)
  (let* ((syms   (escm-env::get-fields self))
	 (symval (mapcar (lambda (s) (cons s (escm-env::gref self s))) syms)))
    `(let ((e (escm-fixed-env::new ,syms)))
       ,@(mapcar (lambda (sv)
		   `(escm-env::gset! e ',(car sv) ,(escm-object::elize (cdr sv))))
		 symval)
       e)))

(escm-cbos::define-method escm-proc escm-object::elize (self)
  )

(provide 'escm-context)
;;; escm-context.el ends here