XPathComparerHelper.cs

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using System;
using System.Collections;
using System.Globalization;
using System.Xml;
using System.Xml.XPath;
 
namespace MS.Internal.Xml.XPath;
 
internal sealed class XPathComparerHelper : IComparer
{
    private readonly XmlSortOrder _order;
 
    private readonly XmlCaseOrder _caseOrder;
 
    private readonly CultureInfo _cinfo;
 
    private readonly XmlDataType _dataType;
 
    public XPathComparerHelper(XmlSortOrder order, XmlCaseOrder caseOrder, string lang, XmlDataType dataType)
    {
        if (lang == null)
        {
            _cinfo = CultureInfo.CurrentCulture;
        }
        else
        {
            try
            {
                _cinfo = new CultureInfo(lang);
            }
            catch (ArgumentException)
            {
                throw;
            }
        }
        if (order == XmlSortOrder.Descending)
        {
            switch (caseOrder)
            {
            case XmlCaseOrder.LowerFirst:
                caseOrder = XmlCaseOrder.UpperFirst;
                break;
            case XmlCaseOrder.UpperFirst:
                caseOrder = XmlCaseOrder.LowerFirst;
                break;
            }
        }
        _order = order;
        _caseOrder = caseOrder;
        _dataType = dataType;
    }
 
    public int Compare(object x, object y)
    {
        switch (_dataType)
        {
        case XmlDataType.Text:
        {
            string @string = Convert.ToString(x, _cinfo);
            string string2 = Convert.ToString(y, _cinfo);
            int num2 = _cinfo.CompareInfo.Compare(@string, string2, (_caseOrder != 0) ? CompareOptions.IgnoreCase : CompareOptions.None);
            if (num2 != 0 || _caseOrder == XmlCaseOrder.None)
            {
                if (_order != XmlSortOrder.Ascending)
                {
                    return -num2;
                }
                return num2;
            }
            num2 = _cinfo.CompareInfo.Compare(@string, string2);
            if (_caseOrder != XmlCaseOrder.LowerFirst)
            {
                return -num2;
            }
            return num2;
        }
        case XmlDataType.Number:
        {
            double num = XmlConvert.ToXPathDouble(x);
            double value = XmlConvert.ToXPathDouble(y);
            int num2 = num.CompareTo(value);
            if (_order != XmlSortOrder.Ascending)
            {
                return -num2;
            }
            return num2;
        }
        default:
            throw new InvalidOperationException(System.SR.Xml_InvalidOperation);
        }
    }
}