/// <summary>
/// Finds the last match whose index is less than or equal to "start".
/// Captures are ordered in the same way as with forward match. This is different from .NET reverse matching.
/// Start is a number of bytes if kcode is given, otherwise it's a number of characters.
/// </summary>
public MatchData LastMatch(MutableString /*!*/ input, int start)
{
string str;
RubyEncoding kcode = null;
Regex regex = Transform(ref kcode, input, 0, out str);
Debug.Assert(str != null);
if (kcode != null)
{
int byteCount;
byte[] bytes = input.GetByteArray(out byteCount);
if (start < 0)
{
start += byteCount;
}
// GetCharCount returns the number of whole characters:
start = (start >= byteCount) ? str.Length : kcode.Encoding.GetCharCount(bytes, 0, start + 1) - 1;
}
else
{
if (start < 0)
{
start += str.Length;
}
if (start > str.Length)
{
start = str.Length;
}
}
Match match;
if (_hasGAnchor)
{
// This only makes some \G anchors work. It seems that CLR doesn't support \G if preceeded by some characters.
// For example, this works in MRI but doesn't in CLR: "abcabczzz".rindex(/.+\G.+/, 3)
match = regex.Match(str, start);
}
else
{
match = LastMatch(regex, str, start);
if (match == null)
{
return(null);
}
}
return(MatchData.Create(match, input, true, str));
}
/// <summary>
/// Reads <paramref name="count"/> bytes from the stream and appends them to the given <paramref name="buffer"/>.
/// If <paramref name="count"/> is <c>Int32.MaxValue</c> the stream is read to the end.
/// Unless <paramref name="preserveEndOfLines"/> is set the line endings in the appended data are normalized to "\n".
/// </summary>
public int AppendBytes(MutableString /*!*/ buffer, int count, bool preserveEndOfLines)
{
ContractUtils.RequiresNotNull(buffer, "buffer");
ContractUtils.Requires(count >= 0, "count");
if (count == 0)
{
return(0);
}
bool readAll = count == Int32.MaxValue;
buffer.SwitchToBytes();
int initialBufferSize = buffer.GetByteCount();
if (preserveEndOfLines)
{
AppendRawBytes(buffer, count);
}
else
{
// allocate 3 more bytes at the end for a backstop and possible LF:
byte[] bytes = Utils.EmptyBytes;
int done = initialBufferSize;
bool eof;
do
{
AppendRawBytes(buffer, readAll ? 1024 : count);
int end = buffer.GetByteCount();
int bytesRead = end - done;
if (bytesRead == 0)
{
break;
}
eof = bytesRead < count;
buffer.EnsureCapacity(end + 3);
int byteCount;
bytes = buffer.GetByteArray(out byteCount);
if (bytes[end - 1] == CR && PeekByte(0) == LF)
{
ReadByte();
bytes[end++] = LF;
}
// insert backstop:
bytes[end] = CR;
bytes[end + 1] = LF;
int last = IndexOfCrLf(bytes, done);
count -= last - done;
done = last;
while (last < end)
{
int next = IndexOfCrLf(bytes, last + 2);
int chunk = next - last - 1;
Buffer.BlockCopy(bytes, last + 1, bytes, done, chunk);
done += chunk;
count -= chunk;
last = next;
}
buffer.Remove(done);
} while (readAll || count > 0 && !eof);
}
if (readAll)
{
buffer.TrimExcess();
}
return(buffer.GetByteCount() - initialBufferSize);
}