org.apache.flink.table.runtime.functions.scalar

Class BuiltInScalarFunction

java.lang.Object

org.apache.flink.table.functions.UserDefinedFunction

org.apache.flink.table.functions.ScalarFunction

org.apache.flink.table.runtime.functions.scalar.BuiltInScalarFunction

All Implemented Interfaces:

Serializable, org.apache.flink.table.functions.FunctionDefinition

Direct Known Subclasses:

ArrayConcatFunction, ArrayContainsFunction, ArrayDistinctFunction, ArrayJoinFunction, ArrayMaxFunction, ArrayMinFunction, ArrayPositionFunction, ArrayRemoveFunction, ArrayReverseFunction, ArraySliceFunction, ArrayUnionFunction, CoalesceFunction, IfNullFunction, MapEntriesFunction, MapFromArraysFunction, MapKeysFunction, MapValuesFunction, SourceWatermarkFunction, TypeOfFunction

@Internal
public abstract class BuiltInScalarFunction
extends org.apache.flink.table.functions.ScalarFunction

Base class for runtime implementation represented as ScalarFunction that is constructed from SpecializedFunction.specialize(SpecializedContext).

Subclasses must offer a constructor that takes SpecializedFunction.SpecializedContext if they are constructed from a BuiltInFunctionDefinition. Otherwise the BuiltInScalarFunction() constructor might be more appropriate.

By default, all built-in functions work on internal data structures. However, this can be changed by overriding getArgumentDataTypes() and getOutputDataType(). Or by overriding getTypeInference(DataTypeFactory) directly.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BuiltInScalarFunction()
protected	BuiltInScalarFunction(org.apache.flink.table.functions.BuiltInFunctionDefinition definition, org.apache.flink.table.functions.SpecializedFunction.SpecializedContext context)

Method Summary

Modifier and Type	Method and Description
List<org.apache.flink.table.types.DataType>	getArgumentDataTypes()
org.apache.flink.table.types.DataType	getOutputDataType()
Set<org.apache.flink.table.functions.FunctionRequirement>	getRequirements()
org.apache.flink.table.types.inference.TypeInference	getTypeInference(org.apache.flink.table.catalog.DataTypeFactory typeFactory)
boolean	isDeterministic()

Methods inherited from class org.apache.flink.table.functions.ScalarFunction

getKind, getParameterTypes, getResultType

Methods inherited from class org.apache.flink.table.functions.UserDefinedFunction

close, functionIdentifier, open, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

BuiltInScalarFunction

protected BuiltInScalarFunction(org.apache.flink.table.functions.BuiltInFunctionDefinition definition,
                                org.apache.flink.table.functions.SpecializedFunction.SpecializedContext context)

BuiltInScalarFunction

protected BuiltInScalarFunction()

Method Detail

getArgumentDataTypes

public List<org.apache.flink.table.types.DataType> getArgumentDataTypes()

getOutputDataType

public org.apache.flink.table.types.DataType getOutputDataType()

getTypeInference

public org.apache.flink.table.types.inference.TypeInference getTypeInference(org.apache.flink.table.catalog.DataTypeFactory typeFactory)

Specified by:

getTypeInference in interface org.apache.flink.table.functions.FunctionDefinition

Overrides:

getTypeInference in class org.apache.flink.table.functions.ScalarFunction

getRequirements

public Set<org.apache.flink.table.functions.FunctionRequirement> getRequirements()

isDeterministic

public boolean isDeterministic()