jellyfin/Emby.Server.Implementations/TextEncoding/NLangDetect/Extensions/StringExtensions.cs

using System;

namespace NLangDetect.Core.Extensions
{
    public static class StringExtensions
    {
        /// <summary>
        /// Returns a new character sequence that is a subsequence of this sequence. The subsequence starts with the character at the specified index and ends with the character at index end - 1. The length of the returned sequence is end - start, so if start == end then an empty sequence is returned.
        /// </summary>
        /// <param name="s"></param>
        /// <param name="start">the start index, inclusive</param>
        /// <param name="end">the end index, exclusive</param>
        /// <returns>the specified subsequence</returns>
        /// <exception cref="IndexOutOfRangeException"> if start or end are negative, if end is greater than length(), or if start is greater than end</exception>
        public static string SubSequence(this string s, int start, int end)
        {
            if (start < 0) throw new ArgumentOutOfRangeException(nameof(start), "Argument must not be negative.");
            if (end < 0) throw new ArgumentOutOfRangeException(nameof(end), "Argument must not be negative.");
            if (end > s.Length) throw new ArgumentOutOfRangeException(nameof(end), "Argument must not be greater than the input string's length.");
            if (start > end) throw new ArgumentOutOfRangeException(nameof(start), "Argument must not be greater than the 'end' argument.");

            return s.Substring(start, end - start);
        }
    }
}