/**
* ************************************************************************************************************
* Attempt to perform natural language generation on this object.
*
* @return a sentence in natural language, or empty string on failure
*/
public String toNaturalLanguage() {
formulateNaturalSubject();
formulateNaturalVerb();
formulateNaturalDirectObject();
formulateNaturalIndirectObject();
if (subject.getSurfaceForm().isEmpty()) {
reset();
doPassiveVoice();
}
// If no subject, perform no NLG.
if (subject.getSurfaceForm().isEmpty()) {
return "";
}
String indirectObjectStr = concatenateIndirectObjects();
String cleanedStr =
(subject.getSurfaceForm()
+ " "
+ verb.getSurfaceForm()
+ " "
+ directObject.getSurfaceForm()
+ " "
+ indirectObjectStr);
return cleanedStr.replaceAll("\\s+", " ").trim();
}
