Csharp/C Sharp/Class Interface/IFormattable

Three dimensional Vector with IFormattable

 
using System;
using System.Collections;
using System.Text;

class MainEntryPoint {
    static void Main(string[] args) {
        Vector Vect1 = new Vector(1.0, 2.0, 5.0);
        foreach (double Component in Vect1) {
            foreach (double Next in Vect1)
                Console.Write("  " + Next);
            Console.WriteLine(Component);
        }
        Console.ReadLine();
    }
}
struct Vector : IFormattable {
    public double x, y, z;
    public IEnumerator GetEnumerator() {
        return new VectorEnumerator(this);
    }
    public Vector(double x, double y, double z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }
    public string ToString(string format, IFormatProvider formatProvider) {
        if (format == null)
            return ToString();
        string formatUpper = format.ToUpper();
        switch (formatUpper) {
            case "N":
                return "|| " + Norm().ToString() + " ||";
            case "VE":
                return String.Format("( {0:E}, {1:E}, {2:E} )", x, y, z);
            case "IJK":
                StringBuilder sb = new StringBuilder(x.ToString(), 30);
                sb.Append(" i + ");
                sb.Append(y.ToString());
                sb.Append(" j + ");
                sb.Append(z.ToString());
                sb.Append(" k");
                return sb.ToString();
            default:
                return ToString();
        }
    }
    public Vector(Vector rhs) {
        x = rhs.x;
        y = rhs.y;
        z = rhs.z;
    }
    public override string ToString() {
        return "( " + x + " , " + y + " , " + z + " )";
    }
    public double this[uint i] {
        get {
            switch (i) {
                case 0:
                    return x;
                case 1:
                    return y;
                case 2:
                    return z;
                default:
                    throw new IndexOutOfRangeException(
                       "Attempt to retrieve Vector element" + i);
            }
        }
        set {
            switch (i) {
                case 0:
                    x = value;
                    break;
                case 1:
                    y = value;
                    break;
                case 2:
                    z = value;
                    break;
                default:
                    throw new IndexOutOfRangeException(
                       "Attempt to set Vector element" + i);
            }
        }
    }
    private const double Epsilon = 0.0000001;
    public static bool operator ==(Vector lhs, Vector rhs) {
        if (System.Math.Abs(lhs.x - rhs.x) < Epsilon &&
           System.Math.Abs(lhs.y - rhs.y) < Epsilon &&
           System.Math.Abs(lhs.z - rhs.z) < Epsilon)
            return true;
        else
            return false;
    }
    public static bool operator !=(Vector lhs, Vector rhs) {
        return !(lhs == rhs);
    }
    public static Vector operator +(Vector lhs, Vector rhs) {
        Vector Result = new Vector(lhs);
        Result.x += rhs.x;
        Result.y += rhs.y;
        Result.z += rhs.z;
        return Result;
    }
    public static Vector operator *(double lhs, Vector rhs) {
        return new Vector(lhs * rhs.x, lhs * rhs.y, lhs * rhs.z);
    }

    public static Vector operator *(Vector lhs, double rhs) {
        return rhs * lhs;
    }
    public static double operator *(Vector lhs, Vector rhs) {
        return lhs.x * rhs.x + lhs.y + rhs.y + lhs.z * rhs.z;
    }
    public double Norm() {
        return x * x + y * y + z * z;
    }
    private class VectorEnumerator : IEnumerator {
        Vector theVector;
        int location;
        public VectorEnumerator(Vector theVector) {
            this.theVector = theVector;
            location = -1;
        }
        public bool MoveNext() {
            ++location;
            return (location > 2) ? false : true;
        }
        public object Current {
            get {
                if (location < 0 || location > 2)
                    throw new InvalidOperationException(
                       "The enumerator is either before the first element or " +
                       "after the last element of the Vector");
                return theVector[(uint)location];
            }
        }
        public void Reset() {
            location = -1;
        }
    }
}