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/**************************************************************************/
/* */
/* The Why platform for program certification */
/* */
/* Copyright (C) 2002-2011 */
/* */
/* Jean-Christophe FILLIATRE, CNRS & Univ. Paris-sud 11 */
/* Claude MARCHE, INRIA & Univ. Paris-sud 11 */
/* Yannick MOY, Univ. Paris-sud 11 */
/* Romain BARDOU, Univ. Paris-sud 11 */
/* */
/* Secondary contributors: */
/* */
/* Thierry HUBERT, Univ. Paris-sud 11 (former Caduceus front-end) */
/* Nicolas ROUSSET, Univ. Paris-sud 11 (on Jessie & Krakatoa) */
/* Ali AYAD, CNRS & CEA Saclay (floating-point support) */
/* Sylvie BOLDO, INRIA (floating-point support) */
/* Jean-Francois COUCHOT, INRIA (sort encodings, hyps pruning) */
/* Mehdi DOGGUY, Univ. Paris-sud 11 (Why GUI) */
/* */
/* This software is free software; you can redistribute it and/or */
/* modify it under the terms of the GNU Lesser General Public */
/* License version 2.1, with the special exception on linking */
/* described in file LICENSE. */
/* */
/* This software 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. */
/* */
/**************************************************************************/
//@ type larray
/* [create(x)] returns an array
* where each cell contains [x]
**/
//@ logic larray create(double x);
//@ logic double select(larray t, integer i);
/*@ logic larray store(larray t, integer i, double x) {
@ axiom select_store_eq:
@ \forall larray t, integer i, double x;
@ select(store(t,i,x),i) == x;
@ axiom select_store_neq:
@ \forall larray t, integer i j;
@ \forall double x;
@ i != j ==>
@ select(store(t,i,x),j) == select(x,j);
@ }
@*/
// public Interface for PArray
interface PArrayInterface {
//@ model larray model_array;
//@ model integer model_length;
/* @ requires n >= 0;
@ ensures
@ this.model_array == create(0.0)
@ && this.model_length == n;
@*/
// PArrayInterface(int n);
/*@ requires 0 <= i < this.model_length;
@ assigns \nothing;
@ ensures \result == select(this.model_array,i);
@*/
double get(int i);
/*@ requires 0 <= i < this.model_length;
@ assigns \nothing;
@ // ensures \fresh(\result);
@ ensures \result.model_array == store(this.model_array,i,x)
@ && \result.model_length == this.model_length;
@*/
PArrayInterface set(int i, double x);
}
abstract class Data {
abstract double get(int i);
abstract PArray set(int i, double x, PArray parent);
}
class Arr extends Data {
double table[];
//@ invariant table_non_null: table != null;
Arr(int n) {
table = new double[n];
}
double get(int i) {
return table[i];
}
PArray set(int i, double x, PArray parent) {
double old = table[i];
table[i] = x;
PArray tmp1 = new PArray(this);
Data tmp2 = new Diff(i,old,tmp1);
parent.contents = tmp2;
return tmp1;
}
public String toString() {
String s = "Arr [";
for (int i = 0; i < table.length; i++)
s += table[i] + "; ";
return (s + "]");
}
}
class Diff extends Data {
private int index;
private double value;
private PArray remaining;
//@ invariant remaining_non_null: remaining != null;
/*@ invariant diff_repr:
@ data_repr(this.remaining.model_length,store(index,value,this.remaining.model_array),this);
@*/
Diff(int i, double x, PArray rem) {
index = i;
value = x;
remaining = rem;
}
double get(int i) {
if (i == index) return value;
return remaining.get(i);
}
PArray set(int i, double x, PArray t) {
Data tmp = new Diff(i,x,t);
return new PArray(tmp);
}
public String toString() {
return "Diff " + index + ", " + value + ", " + remaining;
}
}
public class PArray implements PArrayInterface
{
protected Data contents;
//@ invariant contents_non_null: contents != null;
/*@ invariant data_repr:
@ data_repr(model_length,model_array,contents);
@*/
protected PArray(Data d) {
contents = d;
}
public PArray(int n) {
this(new Arr(n));
}
public double get(int i) {
return contents.get(i);
}
public PArray set(int i, double x) {
return contents.set(i,x,this);
}
public String toString() {
return ("-> " + contents);
}
public static void main(String argv[]) {
PArray t1 = new PArray(4);
PArray t2 = t1.set(0,2.2);
PArray t3 = t2.set(1,3.3);
System.out.println("t1 = " + t1);
System.out.println("t2 = " + t2);
System.out.println("t3 = " + t3);
}
}
/*@ predicate data_repr(integer model_length,
@ larray model_array, Data contents);
@*/
/*@ predicate repr(integer model_length,
@ larray model_array, PArray p);
@*/
/*@ axiom arr_repr :
@ \forall integer model_length, larray model_array, Arr a ;
@ data_repr(model_length, model_array,a)
@ <==>
@ model_length == a.table.length &&
@ \forall integer i;
@ 0 <= i < a.table.length ==> a.table[i] == select(model_array,i) ;
@*/
/*@ axiom diff_repr_1 :
@ \forall integer model_length, larray model_array, Diff d;
@ \forall integer i, double x;
@ repr(model_length, model_array, d.remaining) &&
@ i == d.index && x == d.value
@ ==>
@ data_repr(model_length, store(i,x,model_array),d) ;
@*/
/*@ axiom diff_repr_2 :
@ \forall integer model_length, larray model_array, Diff d ;
@ data_repr(model_length, model_array, d) &&
@ \exists larray a;
@ model_array == store(d.index,d.value,a)
@ &&
@ repr(model_length, a, d.remaining) ;
@*/
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