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package edu.stanford.nlp.objectbank;
import edu.stanford.nlp.util.AbstractIterator;
import java.util.function.Function;
import java.util.List;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.io.Reader;
import java.io.File;
import java.io.IOException;
import java.io.Serializable;
/**
* The ObjectBank class is designed to make it easy to change the format/source
* of data read in by other classes and to standardize how data is read in
* javaNLP classes.
* This should make reuse of existing code (by non-authors of the code)
* easier because one has to just create a new ObjectBank which knows where to
* look for the data and how to turn it into Objects, and then use the new
* ObjectBank in the class. This will also make it easier to reuse code for
* reading in the same data.
*
* An ObjectBank is a Collection of Objects. These objects are taken
* from input sources and then tokenized and parsed into the desired
* kind of Object. An ObjectBank requires a ReaderIteratorFactory and a
* IteratorFromReaderFactory. The ReaderIteratorFactory is used to get
* an Iterator over java.util.Readers which contain representations of
* the Objects. A ReaderIteratorFactory resembles a collection that
* takes input sources and dispenses Iterators over java.util.Readers
* of those sources. A IteratorFromReaderFactory is used to turn a single
* java.io.Reader into an Iterator over Objects. The
* IteratorFromReaderFactory splits the contents of the java.util.Reader
* into Strings and then parses them into appropriate Objects.
*
*
*
Example Usages:
*
* The general case is covered below, but the most common thing people
* actually want to do is read lines from a file. There are special
* methods to make this easy! You use the {@code getLineIterator} method.
* In its simplest use, it returns an {@code ObjectBank}, which is a subclass of
* {@code Collection}. So, statements like these work:
*
*
* for (String str : ObjectBank.getLineIterator(filename) {
* System.out.println(str);
* }
*
* String[] strings = ObjectBank.getLineIterator(filename).toArray(new String[0]);
* String[] strings = ObjectBank.getLineIterator(filename, "GB18030").toArray(new String[0]);
*
*
* More complex uses of getLineIterator let you interpret each line of a file
* as an object of arbitrary type via a transformer Function.
*
* For more general uses with existing classes, you first construct a collection of sources, then a class that
* will make the objects of interest from instances of those sources, and then set up an ObjectBank that can
* vend those objects:
*
{@code
* ReaderIteratorFactory rif = new ReaderIteratorFactory(Arrays.asList(new String[] { "file1", "file2", "file3" }));
* IteratorFromReaderFactory corefIFRF = new MUCCorefIteratorFromReaderFactory(true);
* for (Mention m : new ObjectBank(rif, corefIFRF)) {
* ...
* }
* }
*
* As an example of the general power of this class, suppose you have
* a collection of files in the directory /u/nlp/data/gre/questions. Each file
* contains several Puzzle documents which look like:
*
* <puzzle>
* <preamble> some text </preamble>
* <question> some intro text
* <answer> answer1 </answer>
* <answer> answer2 </answer>
* <answer> answer3 </answer>
* <answer> answer4 </answer>
* </question>
* <question> another question
* <answer> answer1 </answer>
* <answer> answer2 </answer>
* <answer> answer3 </answer>
* <answer> answer4 </answer>
* </question>
* </puzzle>
*
*
* First you need to build a ReaderIteratorFactory which will provide java.io.Readers
* over all the files in your directory:
*
* {@code
* Collection c = new FileSequentialCollection("/u/nlp/data/gre/questions/", "", false);
* ReaderIteratorFactory rif = new ReaderIteratorFactory(c);
* }
*
* Next you need to make an IteratorFromReaderFactory which will take the
* java.io.Readers vended by the ReaderIteratorFactory, split them up into
* documents (Strings) and
* then convert the Strings into Objects. In this case we want to keep everything
* between each set of <puzzle> </puzzle> tags so we would use a BeginEndTokenizerFactory.
* You would also need to write a class which extends Function and whose apply method
* converts the String between the <puzzle> </puzzle> tags into Puzzle objects.
*
* {@code
* public class PuzzleParser implements Function {
* public Object apply (Object o) {
* String s = (String)o;
* ...
* Puzzle p = new Puzzle(...);
* ...
* return p;
* }
* }
* }
*
* Now to build the IteratorFromReaderFactory:
*
*
* {@code IteratorFromReaderFactory rtif = new BeginEndTokenizerFactory("", " ", new PuzzleParser()); }
*
* Now, to create your ObjectBank you just give it the ReaderIteratorFactory and
* IteratorFromReaderFactory that you just created:
*
* {@code ObjectBank puzzles = new ObjectBank(rif, rtif); }
*
* Now, if you get a new set of puzzles that are located elsewhere and formatted differently
* you create a new ObjectBank for reading them in and use that ObjectBank instead with only
* trivial changes (or possible none at all if the ObjectBank is read in on a constructor)
* to your code. Or even better, if someone else wants to use your code to evaluate their puzzles,
* which are located elsewhere and formatted differently, they already know what they have to do
* to make your code work for them.
*
* @author Jenny Finkel [email protected]
* @author Sarah Spikes ([email protected]) - cleanup and filling in types
*/
public class ObjectBank implements Collection, Serializable {
/**
* This creates a new ObjectBank with the given ReaderIteratorFactory
* and ObjectIteratorFactory.
*
* @param rif The {@link ReaderIteratorFactory} from which to get Readers
* @param ifrf The {@link IteratorFromReaderFactory} which turns java.io.Readers
* into Iterators of Objects
*/
public ObjectBank(ReaderIteratorFactory rif, IteratorFromReaderFactory ifrf) {
this.rif = rif;
this.ifrf = ifrf;
}
@SuppressWarnings({"NonSerializableFieldInSerializableClass"})
protected ReaderIteratorFactory rif;
@SuppressWarnings({"NonSerializableFieldInSerializableClass"})
protected IteratorFromReaderFactory ifrf;
@SuppressWarnings({"NonSerializableFieldInSerializableClass"})
private List contents; // = null;
public static ObjectBank getLineIterator(String filename) {
return getLineIterator(new File(filename));
}
public static ObjectBank getLineIterator(String filename, Function op) {
return getLineIterator(new File(filename), op);
}
public static ObjectBank getLineIterator(String filename, String encoding) {
return getLineIterator(new File(filename), encoding);
}
public static ObjectBank getLineIterator(Reader reader) {
return getLineIterator(reader, new IdentityFunction<>());
}
public static ObjectBank getLineIterator(Reader reader, Function op) {
ReaderIteratorFactory rif = new ReaderIteratorFactory(reader);
IteratorFromReaderFactory ifrf = LineIterator.getFactory(op);
return new ObjectBank<>(rif, ifrf);
}
public static ObjectBank getLineIterator(File file) {
return getLineIterator(Collections.singleton(file), new IdentityFunction<>());
}
public static ObjectBank getLineIterator(File file, Function op) {
return getLineIterator(Collections.singleton(file), op);
}
public static ObjectBank getLineIterator(File file, String encoding) {
return getLineIterator(file, new IdentityFunction<>(), encoding);
}
public static ObjectBank getLineIterator(File file, Function op, String encoding) {
ReaderIteratorFactory rif = new ReaderIteratorFactory(file, encoding);
IteratorFromReaderFactory ifrf = LineIterator.getFactory(op);
return new ObjectBank<>(rif, ifrf);
}
public static ObjectBank getLineIterator(Collection filesStringsAndReaders, Function op) {
ReaderIteratorFactory rif = new ReaderIteratorFactory(filesStringsAndReaders);
IteratorFromReaderFactory ifrf = LineIterator.getFactory(op);
return new ObjectBank<>(rif, ifrf);
}
public static ObjectBank getLineIterator(Collection filesStringsAndReaders, String encoding) {
return getLineIterator(filesStringsAndReaders, new IdentityFunction<>(), encoding);
}
public static ObjectBank getLineIterator(Collection filesStringsAndReaders, Function op, String encoding) {
ReaderIteratorFactory rif = new ReaderIteratorFactory(filesStringsAndReaders, encoding);
IteratorFromReaderFactory ifrf = LineIterator.getFactory(op);
return new ObjectBank<>(rif, ifrf);
}
/** This is handy for having getLineIterator return a collection of files for feeding into another ObjectBank. */
public static class PathToFileFunction implements Function {
@Override
public File apply(String str) {
return new File(str);
}
}
@Override
public Iterator iterator() {
// basically concatenates Iterator's made from
// each java.io.Reader.
if (keepInMemory) {
if (contents == null) {
contents = new ArrayList<>();
Iterator iter = new OBIterator();
while (iter.hasNext()) {
contents.add(iter.next());
}
}
return contents.iterator();
}
return new OBIterator();
}
private boolean keepInMemory; // = false;
/**
* Tells the ObjectBank to store all of
* its contents in memory so that it doesn't
* have to be recomputed each time you iterate
* through it. This is useful when the data
* is small enough that it can be kept in
* memory, but reading/processing it
* is expensive/slow. Defaults to false.
*
* @param keep Whether to keep contents in memory
*/
public void keepInMemory(boolean keep) {
keepInMemory = keep;
}
/**
* If you are keeping the contents in memory,
* this will clear the memory, and they will be
* recomputed the next time iterator() is
* called.
*/
public void clearMemory(){
contents = null;
}
@Override
public boolean isEmpty() {
return ! iterator().hasNext();
}
/**
* Can be slow. Usage not recommended.
*/
@Override
public boolean contains(Object o) {
for (E e : this) {
if (e == o) {
return true;
}
}
return false;
}
/**
* Can be slow. Usage not recommended.
*/
@Override
public boolean containsAll(Collection c) {
for (Object obj : c) {
if ( ! contains(obj)) {
return false;
}
}
return true;
}
/**
* Can be slow. Usage not recommended.
*/
@Override
public int size() {
Iterator iter = iterator();
int size = 0;
while (iter.hasNext()) {
size++;
iter.next();
}
return size;
}
@Override
public void clear() {
rif = new ReaderIteratorFactory();
}
@Override
public Object[] toArray() {
Iterator iter = iterator();
ArrayList