A two-dimensional fail-soft array : Indexer « Class Interface « C# / C Sharp
A two-dimensional fail-soft array
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// A two-dimensional fail-soft array.
using System;
class FailSoftArray2D {
int[,] a; // reference to underlying 2D array
int rows, cols; // dimensions
public int Length; // Length is public
public bool errflag; // indicates outcome of last operation
// Construct array given its dimensions.
public FailSoftArray2D(int r, int c) {
rows = r;
cols = c;
a = new int[rows, cols];
Length = rows * cols;
}
// This is the indexer for FailSoftArray2D.
public int this[int index1, int index2] {
// This is the get accessor.
get {
if(ok(index1, index2)) {
errflag = false;
return a[index1, index2];
} else {
errflag = true;
return 0;
}
}
// This is the set accessor.
set {
if(ok(index1, index2)) {
a[index1, index2] = value;
errflag = false;
}
else errflag = true;
}
}
// Return true if indexes are within bounds.
private bool ok(int index1, int index2) {
if(index1 >= 0 & index1 < rows &
index2 >= 0 & index2 < cols)
return true;
return false;
}
}
// Demonstrate a 2D indexer.
public class TwoDIndexerDemo {
public static void Main() {
FailSoftArray2D fs = new FailSoftArray2D(3, 5);
int x;
// show quiet failures
Console.WriteLine("Fail quietly.");
for(int i=0; i < 6; i++)
fs[i, i] = i*10;
for(int i=0; i < 6; i++) {
x = fs[i,i];
if(x != -1) Console.Write(x + " ");
}
Console.WriteLine();
// now, generate failures
Console.WriteLine("\nFail with error reports.");
for(int i=0; i < 6; i++) {
fs[i,i] = i*10;
if(fs.errflag)
Console.WriteLine("fs[" + i + ", " + i + "] out-of-bounds");
}
for(int i=0; i < 6; i++) {
x = fs[i,i];
if(!fs.errflag) Console.Write(x + " ");
else
Console.WriteLine("fs[" + i + ", " + i + "] out-of-bounds");
}
}
}
