org.apache.flink.table.types.inference

Interface CallContext

All Known Implementing Classes:

AdaptedCallContext, UnknownCallContext

@PublicEvolving
public interface CallContext

Provides details about a function call during TypeInference.

Method Summary

Modifier and Type	Method and Description
List<DataType>	getArgumentDataTypes() Returns a resolved list of the call's argument types.
<T> Optional<T>	getArgumentValue(int pos, Class<T> clazz) Returns the literal value of the argument at the given position, given that the argument is a literal, is not null, and can be expressed as an instance of the provided class.
DataTypeLookup	getDataTypeLookup() Enables to lookup types in a catalog and resolve RAW types.
FunctionDefinition	getFunctionDefinition() Returns the function definition that defines the function currently being called.
String	getName() Returns the function's name usually referencing the function in a catalog.
Optional<DataType>	getOutputDataType() Returns the inferred output data type of the function call.
boolean	isArgumentLiteral(int pos) Returns whether the argument at the given position is a value literal.
boolean	isArgumentNull(int pos) Returns true if the argument at the given position is a literal and null, false otherwise.
default ValidationException	newValidationError(String message, Object... args) Creates a validation error for exiting the type inference process with a meaningful exception.

Method Detail

getDataTypeLookup

DataTypeLookup getDataTypeLookup()

Enables to lookup types in a catalog and resolve RAW types.

getFunctionDefinition

FunctionDefinition getFunctionDefinition()

Returns the function definition that defines the function currently being called.

isArgumentLiteral

boolean isArgumentLiteral(int pos)

Returns whether the argument at the given position is a value literal.

isArgumentNull

boolean isArgumentNull(int pos)

Returns true if the argument at the given position is a literal and null, false otherwise.

Use isArgumentLiteral(int) before to check if the argument is actually a literal.

getArgumentValue

<T> Optional<T> getArgumentValue(int pos,
                                 Class<T> clazz)

Returns the literal value of the argument at the given position, given that the argument is a literal, is not null, and can be expressed as an instance of the provided class.

Use isArgumentLiteral(int) before to check if the argument is actually a literal.

getName

String getName()

Returns the function's name usually referencing the function in a catalog.

Note: The name is meant for debugging purposes only.

getArgumentDataTypes

List<DataType> getArgumentDataTypes()

Returns a resolved list of the call's argument types. It also includes a type for every argument in a vararg function call.

getOutputDataType

Optional<DataType> getOutputDataType()

Returns the inferred output data type of the function call.

It does this by inferring the input argument data type using ArgumentTypeStrategy.inferArgumentType(CallContext, int, boolean) of a wrapping call (if available) where this function call is an argument. For example, takes_string(this_function(NULL)) would lead to a DataTypes.STRING() because the wrapping call expects a string argument.

newValidationError

default ValidationException newValidationError(String message,
                                               Object... args)

Creates a validation error for exiting the type inference process with a meaningful exception.