Pchp.Library.Arrays.array_slice C# (CSharp) Method

        public static PhpArray array_slice(PhpArray array, int offset, int length = int.MaxValue, bool preserveKeys = false)
        {
            if (array == null)
            {
                //PhpException.ArgumentNull("array");
                //return null;
                throw new ArgumentNullException();
            }

            // absolutizes range:
            PhpMath.AbsolutizeRange(ref offset, ref length, array.Count);

            var iterator = array.GetFastEnumerator();

            // moves iterator to the first item of the slice;
            // starts either from beginning or from the end (which one is more efficient):
            if (offset < array.Count - offset)
            {
                for (int i = -1; i < offset; i++)
                    if (iterator.MoveNext() == false)
                        break;
            }
            else
            {
                for (int i = array.Count; i > offset; i--)
                    if (iterator.MovePrevious() == false)
                        break;
            }

            // copies the slice:
            PhpArray result = new PhpArray(length);
            int ikey = 0;
            for (int i = 0; i < length; i++)
            {
                var entry = iterator.Current;

                // integer keys are reindexed if preserveKeys is false, string keys are not touched:
                if (preserveKeys || entry.Key.IsString)
                {
                    result.Add(entry.Key, entry.Value);
                }
                else
                {
                    result.Add(ikey++, entry.Value);
                }

                iterator.MoveNext();
            }

            //result.InplaceCopyOnReturn = true;
            return result;
        }