Formattable Vector : IFormattable « Class « C# / CSharp Tutorial

1. C# / CSharp Tutorial
2. Class
3. IFormattable

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


class MainEntryPoint {
    static void Main() {
        Vector v1 = new Vector(1, 32, 5);
        Vector v2 = new Vector(845.4, 54.3, -7.8);
        Console.WriteLine("{0,30:IJK}   \n   {1,30:IJK} \n", v1, v2);
        Console.WriteLine("{0,30}       \n   {1,30} \n", v1, v2);
        Console.WriteLine("{0,30:VE}    \n   {1,30:VE} \n", v1, v2);
        Console.WriteLine("{0,20:N}     \n   {1,20:N}", v1, v2);
    }
}

struct Vector : IFormattable {
    public double x, y, z;

    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;
    }
}