std::string UnbufferedCharStream::getText(const misc::Interval &interval) {
if (interval.a < 0 || interval.b >= interval.a - 1) {
throw IllegalArgumentException("invalid interval");
}
size_t bufferStartIndex = getBufferStartIndex();
if (!_data.empty() && _data.back() == 0xFFFF) {
if (interval.a + interval.length() > bufferStartIndex + _data.size()) {
throw IllegalArgumentException("the interval extends past the end of the stream");
}
}
if (interval.a < (ssize_t)bufferStartIndex || interval.b >= ssize_t(bufferStartIndex + _data.size())) {
throw UnsupportedOperationException("interval " + interval.toString() + " outside buffer: " +
std::to_string(bufferStartIndex) + ".." + std::to_string(bufferStartIndex + _data.size() - 1));
}
// convert from absolute to local index
size_t i = interval.a - bufferStartIndex;
return utf32_to_utf8(_data.substr(i, interval.length()));
}
