v2rayN/v2rayN/ServiceLib/Common/StringEx.cs

using System.Diagnostics.CodeAnalysis;

namespace ServiceLib.Common
{
    public static class StringEx
    {
        public static bool IsNullOrEmpty([NotNullWhen(false)] this string? value)
        {
            return string.IsNullOrEmpty(value);
        }

        public static bool IsNullOrWhiteSpace([NotNullWhen(false)] this string? value)
        {
            return string.IsNullOrWhiteSpace(value);
        }

        public static bool IsNotEmpty([NotNullWhen(false)] this string? value)
        {
            return !string.IsNullOrEmpty(value);
        }

        public static bool BeginWithAny(this string s, IEnumerable<char> chars)
        {
            if (s.IsNullOrEmpty()) return false;
            return chars.Contains(s.First());
        }

        private static bool IsWhiteSpace(this string value)
        {
            return value.All(char.IsWhiteSpace);
        }

        public static IEnumerable<string> NonWhiteSpaceLines(this TextReader reader)
        {
            while (reader.ReadLine() is { } line)
            {
                if (line.IsWhiteSpace()) continue;
                yield return line;
            }
        }

        public static string TrimEx(this string? value)
        {
            return value == null ? string.Empty : value.Trim();
        }

        public static string RemovePrefix(this string value, char prefix)
        {
            return value.StartsWith(prefix) ? value[1..] : value;
        }

        public static string RemovePrefix(this string value, string prefix)
        {
            return value.StartsWith(prefix) ? value[prefix.Length..] : value;
        }

        public static string UpperFirstChar(this string value)
        {
            if (string.IsNullOrEmpty(value))
            {
                return string.Empty;
            }

            return char.ToUpper(value.First()) + value[1..];
        }

        public static string AppendQuotes(this string value)
        {
            return string.IsNullOrEmpty(value) ? string.Empty : $"\"{value}\"";
        }
    }
}