SurrogateChar.cs

Go to the documentation of this file.

using System.Globalization;
using System.Runtime.Serialization;
 
namespace System.Text;
 
internal struct SurrogateChar
{
    private readonly char _lowChar;
 
    private readonly char _highChar;
 
    public const int MinValue = 65536;
 
    public const int MaxValue = 1114111;
 
    private const char surHighMin = '\ud800';
 
    private const char surHighMax = '\udbff';
 
    private const char surLowMin = '\udc00';
 
    private const char surLowMax = '\udfff';
 
    public char LowChar => _lowChar;
 
    public char HighChar => _highChar;
 
    public int Char => (_lowChar - 56320) | ((_highChar - 55296 << 10) + 65536);
 
    public SurrogateChar(int ch)
    {
        if (ch < 65536 || ch > 1114111)
        {
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentException(System.SR.Format(System.SR.XmlInvalidSurrogate, ch.ToString("X", CultureInfo.InvariantCulture)), "ch"));
        }
        _lowChar = (char)(((ch - 65536) & 0x3FF) + 56320);
        _highChar = (char)(((ch - 65536 >> 10) & 0x3FF) + 55296);
    }
 
    public SurrogateChar(char lowChar, char highChar)
    {
        if (lowChar < '\udc00' || lowChar > '\udfff')
        {
            string xmlInvalidLowSurrogate = System.SR.XmlInvalidLowSurrogate;
            int num = lowChar;
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentException(System.SR.Format(xmlInvalidLowSurrogate, num.ToString("X", CultureInfo.InvariantCulture)), "lowChar"));
        }
        if (highChar < '\ud800' || highChar > '\udbff')
        {
            string xmlInvalidHighSurrogate = System.SR.XmlInvalidHighSurrogate;
            int num = highChar;
            throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new ArgumentException(System.SR.Format(xmlInvalidHighSurrogate, num.ToString("X", CultureInfo.InvariantCulture)), "highChar"));
        }
        _lowChar = lowChar;
        _highChar = highChar;
    }
}