/**
* Parse a single <code>Representation</code> from its string representation
*
* @param textualRepresentation the string to be parsed
* @return
* @throws InstantiationException
*/
public static Entry<String, Representation> parseSingleRepresentation(
String textualRepresentation) throws InstantiationException {
int beginHeaderIndex = textualRepresentation.indexOf(BEGIN_REPRESENTATION);
int endHeaderIndex =
textualRepresentation.indexOf(DELIMITER, beginHeaderIndex + BEGIN_REPRESENTATION.length());
String representationHeader =
textualRepresentation.substring(
beginHeaderIndex + BEGIN_REPRESENTATION.length(), endHeaderIndex);
int endRepresentation = textualRepresentation.indexOf(END_REPRESENTATION);
String representationBody =
textualRepresentation.substring(endHeaderIndex + 1, endRepresentation).trim();
logger.debug("representation header: " + representationHeader);
logger.debug("representation body: " + representationBody);
int descriptionSeparator = representationHeader.indexOf(REPRESENTATION_TYPE_NAME_SEPARATOR);
String representationType;
String representationName;
if (descriptionSeparator == -1) {
representationType = representationHeader;
representationName = null;
} else {
representationType = representationHeader.substring(0, descriptionSeparator);
representationName = representationHeader.substring(descriptionSeparator + 1);
}
logger.debug("representation type: " + representationType);
logger.debug("representation name: " + representationName);
Representation representation =
representationFactory.parseRepresentation(representationType, representationBody);
Entry<String, Representation> entry =
new AbstractMap.SimpleEntry<String, Representation>(representationName, representation);
return entry;
}
public static String getTextualRepresentation(Representation representation, String identifier) {
String ret = "";
String representationType =
RepresentationFactory.getRepresentationIdentifier(representation.getClass());
String identifierPart = "";
if (identifier != null) {
identifierPart = ExampleFactory.REPRESENTATION_TYPE_NAME_SEPARATOR + identifier;
}
ret +=
ExampleFactory.BEGIN_REPRESENTATION
+ representationType
+ identifierPart
+ ExampleFactory.DELIMITER
+ " "
+ representation.getTextFromData()
+ ExampleFactory.END_REPRESENTATION
+ representationType
+ ExampleFactory.DELIMITER;
return ret;
}
/**
* It is a factory that provides methods for instantiating an example described in a textual format
* The expected inputs for examples with N labels and M representations are String of the form:
* Label_1 Label_2 ... Label_n |BR_1:I_1| ... |ER_1| |BR_2:I_2| ... |ER_2| ... |BR_m:I_m| ... |ER_m|
* Where the R_i are identifiers of the representation types (some R_i can be the same) while the
* I_i are the specific representation identifier (I_i!=I_j for all i,j) for instance R_1=DV (dense
* vector) I_1=bow
*
* @author Simone Filice
*/
public class ExampleFactory {
private static Logger logger = LoggerFactory.getLogger(ExampleFactory.class);
public static final String LABEL_SEPARATOR = " ";
public static final String REPRESENTATION_TYPE_NAME_SEPARATOR = ":";
public static final String REPRESENTATION_SEPARATOR = " ";
public static final String DELIMITER = "|";
public static final String BEGIN_REPRESENTATION = DELIMITER + "B";
public static final String END_REPRESENTATION = DELIMITER + "E";
public static final String BEGIN_PAIR = DELIMITER + "<" + DELIMITER;
public static final String END_PAIR = DELIMITER + ">" + DELIMITER;
public static final String PAIR_SEPARATOR = DELIMITER + "," + DELIMITER;
private static RepresentationFactory representationFactory = RepresentationFactory.getInstance();;
/**
* Parse a single <code>Representation</code> from its string representation
*
* @param textualRepresentation the string to be parsed
* @return
* @throws InstantiationException
*/
public static Entry<String, Representation> parseSingleRepresentation(
String textualRepresentation) throws InstantiationException {
int beginHeaderIndex = textualRepresentation.indexOf(BEGIN_REPRESENTATION);
int endHeaderIndex =
textualRepresentation.indexOf(DELIMITER, beginHeaderIndex + BEGIN_REPRESENTATION.length());
String representationHeader =
textualRepresentation.substring(
beginHeaderIndex + BEGIN_REPRESENTATION.length(), endHeaderIndex);
int endRepresentation = textualRepresentation.indexOf(END_REPRESENTATION);
String representationBody =
textualRepresentation.substring(endHeaderIndex + 1, endRepresentation).trim();
logger.debug("representation header: " + representationHeader);
logger.debug("representation body: " + representationBody);
int descriptionSeparator = representationHeader.indexOf(REPRESENTATION_TYPE_NAME_SEPARATOR);
String representationType;
String representationName;
if (descriptionSeparator == -1) {
representationType = representationHeader;
representationName = null;
} else {
representationType = representationHeader.substring(0, descriptionSeparator);
representationName = representationHeader.substring(descriptionSeparator + 1);
}
logger.debug("representation type: " + representationType);
logger.debug("representation name: " + representationName);
Representation representation =
representationFactory.parseRepresentation(representationType, representationBody);
Entry<String, Representation> entry =
new AbstractMap.SimpleEntry<String, Representation>(representationName, representation);
return entry;
}
public static String getTextualRepresentation(Representation representation) {
return getTextualRepresentation(representation, null);
}
public static String getTextualRepresentation(Representation representation, String identifier) {
String ret = "";
String representationType =
RepresentationFactory.getRepresentationIdentifier(representation.getClass());
String identifierPart = "";
if (identifier != null) {
identifierPart = ExampleFactory.REPRESENTATION_TYPE_NAME_SEPARATOR + identifier;
}
ret +=
ExampleFactory.BEGIN_REPRESENTATION
+ representationType
+ identifierPart
+ ExampleFactory.DELIMITER
+ " "
+ representation.getTextFromData()
+ ExampleFactory.END_REPRESENTATION
+ representationType
+ ExampleFactory.DELIMITER;
return ret;
}
public static Example parseExample(String exampleDescription) throws InstantiationException {
// System.out.println("INPUT: " + exampleDescription);
int beginFirstRepIndex = exampleDescription.indexOf(DELIMITER);
String labelsPart = exampleDescription.substring(0, beginFirstRepIndex).trim();
String representationsPart = exampleDescription.substring(beginFirstRepIndex).trim();
// System.out.println("Label part: " + labelsPart);
// System.out.println("representation part: " + representationsPart);
Example example;
if (representationsPart.startsWith(BEGIN_PAIR)) {
example = parseExamplePair(representationsPart);
} else {
example = parseSimpleExample(representationsPart);
}
// ADDING LABELS
String[] stringLabels = labelsPart.split(LABEL_SEPARATOR);
for (String labelDescription : stringLabels) {
if (labelDescription.trim().length() > 0) {
Label label = LabelFactory.parseLabel(labelDescription.trim());
example.addLabel(label);
}
}
return example;
}
private static HashMap<String, Representation> parseRepresentations(String representationsPart)
throws InstantiationException {
HashMap<String, Representation> representations = new HashMap<String, Representation>();
String representationRemaining = representationsPart.trim();
int representationCount = 0;
while (representationRemaining.length() > 0) {
int endRepresentationStartIndex = representationRemaining.indexOf(END_REPRESENTATION);
int endRepresentationEndIndex =
representationRemaining.indexOf(DELIMITER, endRepresentationStartIndex + 1);
String representationDescription =
representationRemaining.substring(0, endRepresentationEndIndex + 1);
Entry<String, Representation> entry = parseSingleRepresentation(representationDescription);
representationRemaining =
representationRemaining.substring(endRepresentationEndIndex + 1).trim();
String representationName = entry.getKey();
if (representationName == null) {
representationName = Integer.toString(representationCount);
}
representations.put(representationName, entry.getValue());
representationCount++;
}
return representations;
}
private static SimpleExample parseSimpleExample(String representationsPart)
throws InstantiationException {
SimpleExample example = new SimpleExample();
HashMap<String, Representation> representations = parseRepresentations(representationsPart);
example.setRepresentations(representations);
return example;
}
/**
* Initializes and returns the example described in <code>exampleDescription</code>
*
* @param exampleDescription the the textual description of the example to be instantiated
* @return the example described in <code>exampleDescription</code>
*/
private static ExamplePair parseExamplePair(String examplePairDescription)
throws InstantiationException {
int begin = examplePairDescription.indexOf(BEGIN_PAIR) + BEGIN_PAIR.length();
int end = examplePairDescription.lastIndexOf(END_PAIR);
String pairWithoutBrackets = examplePairDescription.substring(begin, end).trim();
int pairSeparatorIndex = 0;
int beginPairIndex = 0;
int pairSeparatorCount = 0;
int beginPairCount = 1;
while (pairSeparatorCount != beginPairCount) {
pairSeparatorIndex = pairWithoutBrackets.indexOf(PAIR_SEPARATOR, pairSeparatorIndex);
if (pairSeparatorIndex == -1) {
throw new InstantiationException("Imbalanced example pair!");
}
pairSeparatorCount++;
while (true) {
beginPairIndex = pairWithoutBrackets.indexOf(BEGIN_PAIR, beginPairIndex);
if (beginPairIndex == -1 || beginPairIndex > pairSeparatorIndex) {
break;
}
beginPairCount += 1;
beginPairIndex += BEGIN_PAIR.length();
}
pairSeparatorIndex += PAIR_SEPARATOR.length();
}
String leftExampleDescr =
pairWithoutBrackets.substring(0, pairSeparatorIndex - PAIR_SEPARATOR.length()).trim();
String rightExampleDescr = pairWithoutBrackets.substring(pairSeparatorIndex).trim();
Example leftExample = parseExample(leftExampleDescr);
Example rightExample = parseExample(rightExampleDescr);
ExamplePair pair = new ExamplePair(leftExample, rightExample);
if (examplePairDescription.length() > end + END_PAIR.length()) {
String pairDirectRepresentations = examplePairDescription.substring(end + 1);
HashMap<String, Representation> representations =
parseRepresentations(pairDirectRepresentations);
pair.setRepresentations(representations);
}
return pair;
}
}
