close Warning: Can't synchronize with repository "(default)" (The repository directory has changed, you should resynchronize the repository with: trac-admin $ENV repository resync '(default)'). Look in the Trac log for more information.

source: branches/f4grobner/integer-ring.lisp@ 4320

Last change on this file since 4320 was 4312, checked in by Marek Rychlik, 8 years ago

Added ring classes

File size: 2.8 KB
Line 
1;;; -*- Mode: Lisp -*-
2;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
3;;;
4;;; Copyright (C) 1999, 2002, 2009, 2015 Marek Rychlik <rychlik@u.arizona.edu>
5;;;
6;;; This program is free software; you can redistribute it and/or modify
7;;; it under the terms of the GNU General Public License as published by
8;;; the Free Software Foundation; either version 2 of the License, or
9;;; (at your option) any later version.
10;;;
11;;; This program is distributed in the hope that it will be useful,
12;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
13;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14;;; GNU General Public License for more details.
15;;;
16;;; You should have received a copy of the GNU General Public License
17;;; along with this program; if not, write to the Free Software
18;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19;;;
20;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
21
22(defpackage "INTEGER-RING"
23 (:use :cl :copy :ring :rational-field)
24 (:shadowing-import-from "RATIONAL-FIELD" value)
25 (:export "INTEGER-RING"
26 "INTEGER-RING-VALUE"
27 "ADD-TO"
28 "SUBTRACT-FROM"
29 "MULTIPLY-BY"
30 "DIVIDE-BY"
31 "UNARY-MINUS"
32 "UNARY-INVERSE"
33 "UNIVERSAL-GCD"
34 "UNIVERSAL-EZGCD"
35 "UNIVERSAL-EQUALP"
36 "UNIVERSAL-ZEROP"
37 "->SEXP")
38 (:documentation "Wraps integers into an object."))
39
40(in-package "INTEGER-RING")
41
42(defclass integer-ring (rational-field)
43 ((value :initarg :value :initform 0 :accessor integer-ring-value :type integer))
44 (:documentation "An object representing an integer.")
45 )
46
47(defmethod print-object ((self integer-ring) stream)
48 (print-unreadable-object (self stream :type t :identity t)
49 (with-accessors ((value integer-ring-value))
50 self
51 (format stream "VALUE=~A" value))))
52
53(defmethod unary-inverse ((self integer-ring))
54 (with-slots (value)
55 self
56 (case value
57 (1 self)
58 (-1 self)
59 (t
60 (unary-inverse (change-class self 'rational-field))))))
61
62(defmethod universal-gcd ((self integer-ring) (other integer-ring))
63 (with-slots (value)
64 self
65 (with-slots ((other-value value))
66 other
67 (make-instance 'integer-ring :value (gcd value other-value)))))
68
69(defmethod universal-ezgcd ((object integer-ring) (other integer-ring))
70 (with-slots (value)
71 object
72 (with-slots ((other-value value))
73 other
74 (let ((c (gcd value other-value)))
75 (values (make-instance 'integer-ring :value c)
76 (make-instance 'integer-ring :value (/ value c))
77 (make-instance 'integer-ring :value (/ other-value c)))))))
Note: See TracBrowser for help on using the repository browser.