public static object ReverseIndex(MutableString/*!*/ self,
int character, [DefaultProtocol, DefaultParameterValue(-1)]int start) {
start = NormalizeIndex(self, start);
if (start < 0 || character < 0 || character > 255) {
return null;
}
if (start >= self.Length) {
start = self.Length - 1;
}
int result = self.LastIndexOf((byte)character, start);
return (result != -1) ? ScriptingRuntimeHelpers.Int32ToObject(result) : null;
}
public static object LastIndexOf(MutableString/*!*/ self,
int character, [DefaultProtocol, DefaultParameterValue(Int32.MaxValue)]int start) {
if (!self.IsBinaryEncoded && !self.Encoding.IsKCoding && !self.IsAscii()) {
throw RubyExceptions.CreateTypeError("type mismatch: Fixnum given");
}
int byteCount = self.GetByteCount();
start = IListOps.NormalizeIndex(byteCount, start);
if (start < 0 || character < 0 || character > 255) {
return null;
}
if (start >= byteCount) {
start = byteCount - 1;
}
int result = self.LastIndexOf((byte)character, start);
return (result != -1) ? ScriptingRuntimeHelpers.Int32ToObject(result) : null;
}
public static object ReverseIndex(MutableString/*!*/ self,
[DefaultProtocol, NotNull]MutableString/*!*/ substring, [DefaultProtocol]int start) {
start = NormalizeIndex(self, start);
if (start < 0) {
return null;
}
if (substring.IsEmpty) {
return ScriptingRuntimeHelpers.Int32ToObject((start >= self.Length) ? self.Length : start);
}
start += substring.Length - 1;
if (start >= self.Length) {
start = self.Length - 1;
}
int result = self.LastIndexOf(substring, start);
return (result != -1) ? ScriptingRuntimeHelpers.Int32ToObject(result) : null;
}
public static object LastIndexOf(MutableString/*!*/ self,
[DefaultProtocol, NotNull]MutableString/*!*/ substring, [DefaultProtocol, DefaultParameterValue(Int32.MaxValue)]int start) {
self.SwitchToCharacters();
int charCount = self.GetCharCount();
start = IListOps.NormalizeIndex(charCount, start);
if (start < 0) {
return null;
}
if (substring.IsEmpty) {
return ScriptingRuntimeHelpers.Int32ToObject((start >= charCount) ? charCount : start);
}
self.RequireCompatibleEncoding(substring);
substring.SwitchToCharacters();
int subCharCount = substring.GetCharCount();
// LastIndexOf has CLR semantics: no characters of the substring are matched beyond start position.
// Hence we need to increase start by the length of the substring - 1.
if (start > charCount - subCharCount) {
start = charCount - 1;
} else {
start += subCharCount - 1;
}
int result = self.LastIndexOf(substring, start);
return (result != -1) ? ScriptingRuntimeHelpers.Int32ToObject(result) : null;
}
