OffsetEnumerator.cs

using System;
using System.Collections;
using System.Threading.Tasks;
 
namespace Waher.Script.Persistence.SQL.Enumerators
{
    public class OffsetEnumerator : IResultSetEnumerator
    {
        private readonly IResultSetEnumerator e;
        private readonly int offset0;
        private int offset;
 
        public OffsetEnumerator(IResultSetEnumerator ItemEnumerator, int Offset)
        {
            this.e = ItemEnumerator;
            this.offset = this.offset0 = Offset;
        }
 
        public object Current => this.e.Current;
 
        public bool MoveNext()
        {
            return this.MoveNextAsync().Result;
        }
 
        public async Task<bool> MoveNextAsync()
        {
            while (await this.e.MoveNextAsync())
            {
                if (this.offset > 0)
                    this.offset--;
                else
                    return true;
            }
 
            return false;
        }
 
        public void Reset()
        {
            this.offset = this.offset0;
            this.e.Reset();
        }
    }
}