de.up.ling.irtg.codec

Class OutputCodec<E>

java.lang.Object

de.up.ling.irtg.codec.OutputCodec<E>

Direct Known Subclasses:

AlgebraStringRepresentationOutputCodec, BinaryIrtgOutputCodec, BolinasGraphOutputCodec, GraphVizDotOutputCodec, ListOutputCodec, PtbTreeOutputCodec, SgraphAmrOutputCodec, TikzQtreeOutputCodec, TikzSgraphOutputCodec, ToStringOutputCodec, TreeYieldOutputCodec

public abstract class OutputCodec<E>
extends Object

Generates a representation of some object. Representations will typically be strings, but you could also implement an output codec for binary representations.

The objects that a codec can encode must be of the class specified by the type parameter E. For instance, a TikzQtreeOutputCodec will encode objects of class Tree as strings, whereas a SgraphAmrOutputCodec will encode objects of class SGraph as strings.

Concrete output codec implementations must implement the abstract method write(java.lang.Object, java.io.OutputStream), which writes a representation of an object to some output stream. This class then provides a number of convenience methods that make use of the concrete implementation of write.

Output codecs can be registered by adding them to the file src/main/resources/META-INF/services/de.up.ling.codec.OutputCodec. Output codecs that are suitable for a given class of objects can then be found using getOutputCodecs(java.lang.Class). For instance, the Alto GUI allows the user to right-click on an object to obtain a string representation; the possible string representations are automatically discovered from the output codecs that are available for that object.

In order to be discovered correctly, each output codec needs to be annotated with CodecMetadata. Most importantly, the "type" field of that annotation specifies the class that the codec can encode.

Author:

koller

Constructor Summary

Constructors

Constructor and Description
OutputCodec()

Method Summary

Modifier and Type	Method and Description
void	addOptions(String options)
String	asString(E object) Returns a string representation of the given object.
Supplier<String>	asStringSupplier(E object) Returns a function that computes a string representation of the given object.
static Iterable<OutputCodec>	getAllOutputCodecs() Returns all registered output codecs.
CodecMetadata	getMetadata() Returns the metadata associated with this output object.
String	getOption(String key)
static OutputCodec	getOutputCodecByExtension(String extension)
static OutputCodec	getOutputCodecByName(String name) Returns the registered input codec with the given name (as per the codec metadata's name field).
static <T> List<OutputCodec<T>>	getOutputCodecs(Class<T> forClass) Returns a list of all output codecs that can encode objects of the given class.
boolean	hasTrueOption(String key)
abstract void	write(E object, OutputStream ostream) Writes a string representation of a given object to an output stream.

Methods inherited from class java.lang.Object

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

Constructor Detail

OutputCodec

public OutputCodec()

Method Detail

write

public abstract void write(E object,
                           OutputStream ostream)
                    throws IOException,
                           UnsupportedOperationException

Writes a string representation of a given object to an output stream. Implement this method to implement your own concrete encoding.

Parameters:

object -

ostream -

Throws:

IOException - if something went wrong with I/O

UnsupportedOperationException - if a problem occurred in computing the representation of the object

asStringSupplier

public Supplier<String> asStringSupplier(E object)

Returns a function that computes a string representation of the given object. The string representation itself is only computed when the function is called, so any errors that occur when encoding will only happen at that time.

Parameters:

object -

Returns:

asString

public String asString(E object)
                throws UnsupportedOperationException

Returns a string representation of the given object. Internally, this method calls write(java.lang.Object, java.io.OutputStream) and writes a representation into a string.

Parameters:

object -

Returns:

Throws:

UnsupportedOperationException - if a problem occurred in computing the representation of the object

getAllOutputCodecs

public static Iterable<OutputCodec> getAllOutputCodecs()

Returns all registered output codecs. You can register a new output codec by adding its fully qualified class name to the file META-INF/services/de.up.ling.irtg.codec.OutputCodec. You can find this file under src/main/resources in the IRTG source code repository. Note: It is usually a better idea to call getOutputCodecs(java.lang.Class) to ensure type-safety.

Returns:

getOutputCodecs

public static <T> List<OutputCodec<T>> getOutputCodecs(Class<T> forClass)

Returns a list of all output codecs that can encode objects of the given class.

Type Parameters:

T -

Parameters:

forClass -

Returns:

getOutputCodecByName

public static OutputCodec getOutputCodecByName(String name)

Returns the registered input codec with the given name (as per the codec metadata's name field). If no codec with this name can be found, returns null.

Parameters:

name -

Returns:

getOutputCodecByExtension

public static OutputCodec getOutputCodecByExtension(String extension)

getMetadata

public CodecMetadata getMetadata()

Returns the metadata associated with this output object.

Returns:

addOptions

public void addOptions(String options)

getOption

public String getOption(String key)

hasTrueOption

public boolean hasTrueOption(String key)