private void UpdateState(int value)
{
// This switch is marginally faster than a dictionary and significantly faster than Hashtable
value = _delimiters.Contains(value) ? Delimiter : value;
switch (value)
{
case NoData:
_state = LexingStates.NoData;
break;
case Delimiter:
_state = LexingStates.StartingNextField;
break;
case EndOfLine:
_state = LexingStates.EndOfLine;
break;
case WindowsEndOfLine:
_state = LexingStates.WindowsEndOfLine;
break;
case Quote:
_state = LexingStates.ReadingQuoted;
break;
default:
_state = LexingStates.ReadingField;
break;
}
}
public string GetNextField()
{
UpdateState(Initialize);
while ((_state & BreakCondition) != _state)
{
var currentValue = _reader.Read();
UpdateState(currentValue);
switch (_state)
{
case LexingStates.WindowsEndOfLine:
// just skip because the next character is probably going to be \n
continue;
case LexingStates.ReadingField:
_buffer.Append((char)currentValue);
break;
case LexingStates.StartingNextField:
case LexingStates.EndOfLine:
case LexingStates.NoData:
break;
case LexingStates.ReadingQuoted:
currentValue = _reader.Read();
while (currentValue != Quote)
{
_buffer.Append((char)currentValue);
currentValue = _reader.Read();
}
_state = LexingStates.ReadingField;
continue;
default:
throw new ArgumentOutOfRangeException($"Unknown state '{_state}'");
}
}
var field = _buffer.ToString();
_buffer.Clear();
return(field);
}