Package org.apache.flink.table.types.inference.strategies

Class ConstraintArgumentTypeStrategy

java.lang.Object

org.apache.flink.table.types.inference.strategies.ConstraintArgumentTypeStrategy

All Implemented Interfaces:

ArgumentTypeStrategy

@Internal
public final class ConstraintArgumentTypeStrategy
extends Object
implements ArgumentTypeStrategy

Strategy for an argument that must fulfill a given constraint.

Constructor Summary

Constructors

Constructor	Description
ConstraintArgumentTypeStrategy(String constraintMessage, Predicate<List<DataType>> evaluator)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)
Signature.Argument	getExpectedArgument(FunctionDefinition functionDefinition, int argumentPos)	Returns a summary of the function's expected argument at argumentPos.
int	hashCode()
Optional<DataType>	inferArgumentType(CallContext callContext, int argumentPos, boolean throwOnFailure)	Main logic for inferring and validating an argument.

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstraintArgumentTypeStrategy

public ConstraintArgumentTypeStrategy(String constraintMessage,
                                      Predicate<List<DataType>> evaluator)

Method Detail

inferArgumentType

public Optional<DataType> inferArgumentType(CallContext callContext,
                                            int argumentPos,
                                            boolean throwOnFailure)

Description copied from interface: ArgumentTypeStrategy

Main logic for inferring and validating an argument. Returns the data type that is valid for the given call. If the returned type differs from CallContext.getArgumentDataTypes() at argumentPos, a casting operation can be inserted. An empty result means that the given input type could not be inferred.

Specified by:

inferArgumentType in interface ArgumentTypeStrategy

Parameters:

callContext - provides details about the function call

argumentPos - argument index in the CallContext

throwOnFailure - whether this function is allowed to throw an ValidationException with a meaningful exception in case the inference is not successful or if this function should simply return an empty result.

Returns:

three-state result for either "true, same data type as argument", "true, but argument must be casted to returned data type", or "false, no inferred data type could be found"

See Also:

CallContext.newValidationError(String, Object...)

getExpectedArgument

public Signature.Argument getExpectedArgument(FunctionDefinition functionDefinition,
                                              int argumentPos)

Description copied from interface: ArgumentTypeStrategy

Returns a summary of the function's expected argument at argumentPos.

Specified by:

getExpectedArgument in interface ArgumentTypeStrategy

Parameters:

functionDefinition - the function definition that defines the function currently being called.

argumentPos - the position within the function call for which the signature should be retrieved

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object