IntExtentions.cs

namespace System
{
    public static class IntExtentions
    {
        #region [ Times ]
        public static void Times(this int self, Action action)
        {
            Throw.IfIsNull(action);
            Throw.IfLessThanOrEqZero(self);

            for (int i = 0; i < self; i++)
                action();
        }

        public static void Times(this int self, Action<int> action)
        {
            Throw.IfIsNull(action);
            Throw.IfLessThanOrEqZero(self);

            for (int i = 0; i < self; i++)
                action(i);
        }
        #endregion [ Times ]

        #region [ PercentOf ]
        public static int PercentOf(this int self, int value)
        {
            return (value * self) / 100;
        }

        public static long PercentOf(this int self, long value)
        {
            return (value * self) / 100;
        }

        public static float PercentOf(this int self, float value)
        {
            return (value * self) / 100;
        }

        public static decimal PercentOf(this int self, decimal value)
        {
            return (value * self) / 100;
        }

        public static double PercentOf(this int self, double value)
        {
            return (value * self) / 100;
        }
        #endregion [ PercentOf ]

        public static double Pow(this int self, int y)
        {
            return Math.Pow(self, y);
        }

        public static double Factorial(this int self)
        {
            if (self <= 1)
                return 1;
            else
                return self * Factorial(self - 1);
        }
        
        //Test: phrase = "{{|One|Two}} {{|car|cars}}"
        //Test: phrase = "{{0|1|[value]}} {{|car|cars}}"        
        public static string Pluralization(this int self, string phrase)
        {
            var valuePhrase = Regex.Replace(phrase, @"\[value]", self.ToString());
            var result = Regex.Match(valuePhrase, @"\{{.*?\}}");

            foreach (Group group in result.Groups)
            {
                if (string.IsNullOrWhiteSpace(group.Value))
                    break;

                var content = group.Value.Replace("{{", "").Replace("}}", "");
                var parts = content.Split('|');

                Throw.IfIsFalse(parts.Length == 3, new IndexOutOfRangeException(string.Format("Invalid content template: {0}", group.Value)));

                var newPhrase = string.Empty;
                if (self == 0)
                    newPhrase = valuePhrase.Replace(group.Value, parts[0]);
                if (self == 1)
                    newPhrase = valuePhrase.Replace(group.Value, parts[1]);
                if (self > 1)
                    newPhrase = valuePhrase.Replace(group.Value, parts[2]);

                return self.Pluralization(newPhrase);
            }

            return phrase;
        }        
    }
}