;;; -*- mode: Lisp; Syntax: Common-Lisp; -*-
;;;
;;; Copyright (c) 2009 by the authors.
;;;
;;; See LICENCE for details.

(in-package :hu.dwim.excosy)

;;;;;;
;;; object

(def class* object ()
  ((name
    :type string
    :documentation "A unique name of this object.")
   (reader-function
    :type symbol
    :documentation "A function that reads an instance of this object from a sequence of characters.")
   (printer-function
    :type symbol
    :documentation "A function that prints an instance of this object into a sequence of characters.")
   (interpreter-function
    :type symbol
    :documentation "")
   (memory-location-function
    :type symbol
    :documentation "A function that provides the memory location for an instance of this object."))
  (:documentation "Objects are the most basic building blocks in the system. In fact, everything is an object."))

;;;;;;
;;; value-type

(def class* value-type ()
  ((name :type symbol)
   (reader-function :type symbol)
   (printer-function :type symbol)
   (interpreter-function :type symbol)
   (memory-location-allocator-function :type symbol)))

(def class* actual-value ()
  ((value-type :type value-type)
   (memory-location :type integer)))

(def function make-value-type (name)
  (make-instance 'value-type
                 :name name
                 :reader-function (format-symbol :hu.dwim.excosy "READ-~A" name)
                 :printer-function (format-symbol :hu.dwim.excosy "PRINT-~A" name)
                 :interpreter-function (format-symbol :hu.dwim.excosy "INTERPRET-~A" name)
                 :memory-location-allocator-function (format-symbol :hu.dwim.excosy "INTERPRET-~A" name)))

(def function make-value-type/nothing ()
  (make-value-type 'boolean))

(def function make-value-type/boolean ()
  (make-instance 'value-type
                 :reader-function
                 :printer-function
                 :interpreter-function
                 :memory-location-allocator-function))

(def function make-value-type/native-integer ()
  (make-instance 'value-type
                 :reader-function 'read-native-integer
                 :printer-function 'print-native-integer
                 :interpreter-function 'interpret-native-integer
                 :memory-location-allocator-function))

(def function make-value-type/tagged-integer ()
  (make-instance 'value-type
                 :reader-function
                 :printer-function
                 :interpreter-function
                 :memory-location-allocator-function))