for(int i = first; i >= 0 && i < end; i += increment){
buffer.appendCodePoint(s.charAt(i));
}
} else {
for(int j = first; j >= 0 && j > end && j < getValue().length(); j += increment){
buffer.appendCodePoint(s.charAt(j));
}
}
return makeResult(TypeFactory.getInstance().stringType(), getValueFactory().string(buffer.toString()), ctx);
}