The Enumerable Enumerator

/*
Copyright (c) 2006, Marc Clifton
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using System;
using System.Collections.Generic;

// Ordinal: Being of a specified position in a numbered series

// The Enumerable Enumerator!

namespace Clifton.Tools.Data
{
    public static class Enumerator<T>
    {
        /// <summary>
        /// Returns the first value in the enumeration, as sorted
        /// by enum value, not ordinal value.
        /// </summary>
        public static T First
        {
            get { return ((T[])Enum.GetValues(typeof(T)))[0]; }
        }

        /// <summary>
        /// Returns the last vaue in the enumeration, as sorted
        /// by enum value, not ordinal value.
        /// </summary>
        public static T Last
        {
            get 
            {
                T[] vals = (T[])Enum.GetValues(typeof(T));
                return vals[vals.Length-1]; 
            }
        }

		public static T PreviousBounded(T val, T min)
		{
			T[] vals = (T[])Enum.GetValues(typeof(T));
			int curIdx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(val); });
			int minIdx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(min); });

			return curIdx <= minIdx ? vals[minIdx] : vals[curIdx - 1];
		}

		public static T NextBounded(T val, T max)
		{
			T[] vals = (T[])Enum.GetValues(typeof(T));
			int curIdx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(val); });
			int maxIdx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(max); });

			return curIdx >= maxIdx ? vals[maxIdx] : vals[curIdx + 1];
		}

        /// <summary>
        /// Returns the enumeration value that is previous to the supplied one,
        /// or the first enumeration value, based on enum value, not ordinal value.
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static T PreviousOrFirst(T val)
        {
            T[] vals = (T[])Enum.GetValues(typeof(T));
            int idx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(val); });

            return idx == 0 ? vals[0] : vals[idx - 1];
        }

        /// <summary>
        /// Returns the enumeration value that is next to the supplied one,
        /// or the last enumeration value based on enum value, not ordinal value.
        /// </summary>
        /// <param name="val"></param>
        /// <returns></returns>
        public static T NextOrLast(T val)
        {
            T[] vals = (T[])Enum.GetValues(typeof(T));
            int idx = Array.FindIndex<T>(vals, delegate(T v) { return v.Equals(val); });

            return idx == vals.Length-1 ? vals[idx] : vals[idx + 1];
        }

        /// <summary>
        /// Iterates over the enumeration collection by enum value, not ordinal value.
        /// </summary>
        /// <returns></returns>
		public static IEnumerable<T> Items()
		{
			return (T[])Enum.GetValues(typeof(T));
		}
    }
}