org.apache.lucene.util.fst

Class Outputs<T>

java.lang.Object

org.apache.lucene.util.fst.Outputs<T>

Direct Known Subclasses:

ByteSequenceOutputs, CharSequenceOutputs, IntSequenceOutputs, NoOutputs, PairOutputs, PositiveIntOutputs

public abstract class Outputs<T>
extends Object

Represents the outputs for an FST, providing the basic algebra required for building and traversing the FST.

Note that any operation that returns NO_OUTPUT must return the same singleton object from getNoOutput().

WARNING: This API is experimental and might change in incompatible ways in the next release.

Constructor Summary

Constructors

Constructor and Description
Outputs()

Method Summary

Methods

Modifier and Type	Method and Description
abstract T	add(T prefix, T output) Eg add("foo", "bar") -> "foobar"
abstract T	common(T output1, T output2) Eg common("foo", "foobar") -> "foo"
abstract T	getNoOutput() NOTE: this output is compared with == so you must ensure that all methods return the single object if it's really no output
T	merge(T first, T second)
abstract String	outputToString(T output)
abstract T	read(DataInput in) Decode an output value previously written with write(Object, DataOutput).
T	readFinalOutput(DataInput in) Decode an output value previously written with writeFinalOutput(Object, DataOutput).
abstract T	subtract(T output, T inc) Eg subtract("foobar", "foo") -> "bar"
abstract void	write(T output, DataOutput out) Encode an output value into a DataOutput.
void	writeFinalOutput(T output, DataOutput out) Encode an final node output value into a DataOutput.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Outputs

public Outputs()

Method Detail

common

public abstract T common(T output1,
       T output2)

Eg common("foo", "foobar") -> "foo"

subtract

public abstract T subtract(T output,
         T inc)

Eg subtract("foobar", "foo") -> "bar"

add

public abstract T add(T prefix,
    T output)

Eg add("foo", "bar") -> "foobar"

write

public abstract void write(T output,
         DataOutput out)
                    throws IOException

Encode an output value into a DataOutput.

Throws:

IOException

writeFinalOutput

public void writeFinalOutput(T output,
                    DataOutput out)
                      throws IOException

Encode an final node output value into a DataOutput. By default this just calls write(Object, DataOutput).

Throws:

IOException

read

public abstract T read(DataInput in)
                throws IOException

Decode an output value previously written with write(Object, DataOutput).

Throws:

IOException

readFinalOutput

public T readFinalOutput(DataInput in)
                  throws IOException

Decode an output value previously written with writeFinalOutput(Object, DataOutput). By default this just calls read(DataInput).

Throws:

IOException

getNoOutput

public abstract T getNoOutput()

NOTE: this output is compared with == so you must ensure that all methods return the single object if it's really no output

outputToString

public abstract String outputToString(T output)

merge

public T merge(T first,
      T second)