/// <summary>
/// Reports the zero-based index of the last occurrence of the specified <paramref name="value"/> in the current <paramref name="span"/>.
/// <param name="span">The source span.</param>
/// <param name="value">The value to seek within the source span.</param>
/// <param name="comparisonType">One of the enumeration values that determines how the <paramref name="span"/> and <paramref name="value"/> are compared.</param>
/// </summary>
public static int LastIndexOf(this ReadOnlySpan <char> span, ReadOnlySpan <char> value, StringComparison comparisonType)
{
string.CheckStringComparison(comparisonType);
if (value.Length == 0)
{
return(span.Length > 0 ? span.Length - 1 : 0);
}
if (span.Length == 0)
{
return(-1);
}
if (GlobalizationMode.Invariant)
{
return(CompareInfo.InvariantIndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType) != CompareOptions.None, fromBeginning: false));
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
case StringComparison.CurrentCultureIgnoreCase:
return(CultureInfo.CurrentCulture.CompareInfo.LastIndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
case StringComparison.InvariantCulture:
case StringComparison.InvariantCultureIgnoreCase:
return(CompareInfo.Invariant.LastIndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
default:
Debug.Assert(comparisonType == StringComparison.Ordinal || comparisonType == StringComparison.OrdinalIgnoreCase);
return(CompareInfo.Invariant.LastIndexOfOrdinal(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType) != CompareOptions.None));
}
}
public static int IndexOfCultureIgnoreCaseHelper(ReadOnlySpan <char> span, ReadOnlySpan <char> value, CompareInfo compareInfo)
{
Debug.Assert(span.Length != 0);
Debug.Assert(value.Length != 0);
if (GlobalizationMode.Invariant)
{
return(CompareInfo.InvariantIndexOf(span, value, ignoreCase: true));
}
return(compareInfo.IndexOf(span, value, CompareOptions.IgnoreCase));
}
public static int IndexOfOrdinalHelper(ReadOnlySpan <char> span, ReadOnlySpan <char> value, bool ignoreCase)
{
Debug.Assert(span.Length != 0);
Debug.Assert(value.Length != 0);
if (GlobalizationMode.Invariant)
{
return(CompareInfo.InvariantIndexOf(span, value, ignoreCase));
}
return(CompareInfo.Invariant.IndexOfOrdinal(span, value, ignoreCase));
}
/// <summary>
/// Reports the zero-based index of the first occurrence of the specified <paramref name="value"/> in the current <paramref name="span"/>.
/// <param name="span">The source span.</param>
/// <param name="value">The value to seek within the source span.</param>
/// <param name="comparisonType">One of the enumeration values that determines how the <paramref name="span"/> and <paramref name="value"/> are compared.</param>
/// </summary>
public static int IndexOf(this ReadOnlySpan <char> span, ReadOnlySpan <char> value, StringComparison comparisonType)
{
string.CheckStringComparison(comparisonType);
if (value.Length == 0)
{
return(0);
}
if (span.Length == 0)
{
return(-1);
}
if (comparisonType == StringComparison.Ordinal)
{
return(SpanHelpers.IndexOf(
ref MemoryMarshal.GetReference(span),
span.Length,
ref MemoryMarshal.GetReference(value),
value.Length));
}
if (GlobalizationMode.Invariant)
{
return(CompareInfo.InvariantIndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType) != CompareOptions.None));
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
case StringComparison.CurrentCultureIgnoreCase:
return(CultureInfo.CurrentCulture.CompareInfo.IndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
case StringComparison.InvariantCulture:
case StringComparison.InvariantCultureIgnoreCase:
return(CompareInfo.Invariant.IndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
default:
Debug.Assert(comparisonType == StringComparison.OrdinalIgnoreCase);
return(CompareInfo.Invariant.IndexOfOrdinalIgnoreCase(span, value));
}
}
/// <summary>
/// Reports the zero-based index of the first occurrence of the specified <paramref name="value"/> in the current <paramref name="span"/>.
/// <param name="span">The source span.</param>
/// <param name="value">The value to seek within the source span.</param>
/// <param name="comparisonType">One of the enumeration values that determines how the <paramref name="span"/> and <paramref name="value"/> are compared.</param>
/// </summary>
public static int IndexOf(this ReadOnlySpan <char> span, ReadOnlySpan <char> value, StringComparison comparisonType)
{
string.CheckStringComparison(comparisonType);
if (value.Length == 0)
{
return(0);
}
if (span.Length == 0)
{
return(-1);
}
if (GlobalizationMode.Invariant)
{
return(CompareInfo.InvariantIndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType) != CompareOptions.None));
}
switch (comparisonType)
{
case StringComparison.CurrentCulture:
case StringComparison.CurrentCultureIgnoreCase:
return(CultureInfo.CurrentCulture.CompareInfo.IndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
case StringComparison.InvariantCulture:
case StringComparison.InvariantCultureIgnoreCase:
return(CompareInfo.Invariant.IndexOf(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType)));
case StringComparison.Ordinal:
case StringComparison.OrdinalIgnoreCase:
return(CompareInfo.Invariant.IndexOfOrdinal(span, value, string.GetCaseCompareOfComparisonCulture(comparisonType) != CompareOptions.None));
}
Debug.Fail("StringComparison outside range");
return(-1);
}
