org.tribuo.data.columnar.extractors

Class SimpleFieldExtractor<T>

java.lang.Object

org.tribuo.data.columnar.extractors.SimpleFieldExtractor<T>

All Implemented Interfaces:

com.oracle.labs.mlrg.olcut.config.Configurable, com.oracle.labs.mlrg.olcut.provenance.Provenancable<com.oracle.labs.mlrg.olcut.provenance.ConfiguredObjectProvenance>, FieldExtractor<T>

Direct Known Subclasses:

DateExtractor, DoubleExtractor, FloatExtractor, IdentityExtractor, IntExtractor, OffsetDateTimeExtractor

public abstract class SimpleFieldExtractor<T>
extends Object
implements FieldExtractor<T>

Extracts a value from a single field to be placed in an Example's metadata field.

Field Summary

Fields

Modifier and Type	Field and Description
protected String	fieldName
protected String	metadataName

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SimpleFieldExtractor() For olcut.
protected	SimpleFieldExtractor(String fieldName) Constructs a simple field extractor which reads from the supplied field name and writes out to a metadata field with the same name.
protected	SimpleFieldExtractor(String fieldName, String metadataName) Constructs a simple field extractor with the supplied field name and metadata field name.

Method Summary

Modifier and Type	Method and Description
Optional<T>	extract(ColumnarIterator.Row row) Returns Optional which is filled if extraction succeeded.
protected abstract Optional<T>	extractField(String fieldValue) Extracts the field value, or returns Optional.empty() if it failed to parse.
String	getFieldName() Gets the field name this extractor operates on.
String	getMetadataName() Gets the metadata key name.
void	postConfig() Used by the OLCUT configuration system, and should not be called by external code.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.tribuo.data.columnar.FieldExtractor

getValueType

Methods inherited from interface com.oracle.labs.mlrg.olcut.provenance.Provenancable

getProvenance

Field Detail

fieldName

@Config(mandatory=true,
        description="The field name to read.")
protected String fieldName

metadataName

@Config(description="The metadata key to emit, defaults to field name if unpopulated")
protected String metadataName

Constructor Detail

SimpleFieldExtractor

protected SimpleFieldExtractor(String fieldName)

Constructs a simple field extractor which reads from the supplied field name and writes out to a metadata field with the same name.

Parameters:

fieldName - The field name to read from.

SimpleFieldExtractor

protected SimpleFieldExtractor(String fieldName,
                               String metadataName)

Constructs a simple field extractor with the supplied field name and metadata field name.

Parameters:

fieldName - The field name to read.

metadataName - The metadata field name to write to.

SimpleFieldExtractor

protected SimpleFieldExtractor()

For olcut.

Method Detail

postConfig

public void postConfig()

Used by the OLCUT configuration system, and should not be called by external code.

Specified by:

postConfig in interface com.oracle.labs.mlrg.olcut.config.Configurable

getFieldName

public String getFieldName()

Gets the field name this extractor operates on.

Returns:

The field name.

getMetadataName

public String getMetadataName()

Gets the metadata key name. This is the key into which this value will be written in an Example if it is given to RowProcessor.

Defaults to the field name.

Specified by:

getMetadataName in interface FieldExtractor<T>

Returns:

The metadata key name.

extractField

protected abstract Optional<T> extractField(String fieldValue)

Extracts the field value, or returns Optional.empty() if it failed to parse.

Parameters:

fieldValue - The field value to read.

Returns:

The extracted value.

extract

public Optional<T> extract(ColumnarIterator.Row row)

Description copied from interface: FieldExtractor

Returns Optional which is filled if extraction succeeded.

Specified by:

extract in interface FieldExtractor<T>

Parameters:

row - The raw row from which to extract a value

Returns:

A value.

toString

public String toString()

Overrides:

toString in class Object