Package org.apache.druid.math.expr

Class ApplyFunction.FilterFunction

java.lang.Object

org.apache.druid.math.expr.ApplyFunction.FilterFunction

All Implemented Interfaces:

ApplyFunction, NamedFunction

Enclosing interface:

ApplyFunction

public static class ApplyFunction.FilterFunction
extends Object
implements ApplyFunction

Filter an array to all elements that evaluate to a 'truthy' value for a LambdaExpr

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.druid.math.expr.ApplyFunction

ApplyFunction.AllMatchFunction, ApplyFunction.AnyMatchFunction, ApplyFunction.BaseFoldFunction, ApplyFunction.BaseMapFunction, ApplyFunction.CartesianFoldFunction, ApplyFunction.CartesianFoldLambdaBinding, ApplyFunction.CartesianMapFunction, ApplyFunction.CartesianMapLambdaBinding, ApplyFunction.FilterFunction, ApplyFunction.FoldFunction, ApplyFunction.FoldLambdaBinding, ApplyFunction.IndexableFoldLambdaBinding, ApplyFunction.IndexableMapLambdaObjectBinding, ApplyFunction.LambdaInputBindingInspector, ApplyFunction.MapFunction, ApplyFunction.MapLambdaBinding, ApplyFunction.MatchFunction, ApplyFunction.SettableLambdaBinding

Constructor Summary

Constructors

Constructor	Description
FilterFunction()

Method Summary

Modifier and Type	Method	Description
ExprEval	apply(org.apache.druid.math.expr.LambdaExpr lambdaExpr, List<Expr> argsExpr, Expr.ObjectBinding bindings)	Apply LambdaExpr to argument list of Expr given a set of outer Expr.ObjectBinding.
Set<Expr>	getArrayInputs(List<Expr> args)	Get list of input arguments which must evaluate to an array ExprType
ExpressionType	getOutputType(Expr.InputBindingInspector inspector, org.apache.druid.math.expr.LambdaExpr expr, List<Expr> args)	Compute the output type of this function for a given lambda and the argument expressions which will be applied as its inputs.
boolean	hasArrayOutput(org.apache.druid.math.expr.LambdaExpr lambdaExpr)	Returns true if apply function produces an array output.
String	name()	Name of the function
void	validateArguments(org.apache.druid.math.expr.LambdaExpr lambdaExpr, List<Expr> args)	Validate function arguments.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.druid.math.expr.ApplyFunction

asVectorProcessor, canVectorize

Methods inherited from interface org.apache.druid.math.expr.NamedFunction

processingFailed, validationFailed, validationFailed, validationHelperCheckAnyOfArgumentCount, validationHelperCheckArgIsLiteral, validationHelperCheckArgumentCount, validationHelperCheckArgumentCount, validationHelperCheckArgumentRange, validationHelperCheckLambaArgumentCount, validationHelperCheckMinArgumentCount, validationHelperCheckMinArgumentCount

Constructor Detail

FilterFunction

public FilterFunction()

Method Detail

name

public String name()

Description copied from interface: NamedFunction

Name of the function

Specified by:

name in interface NamedFunction

hasArrayOutput

public boolean hasArrayOutput(org.apache.druid.math.expr.LambdaExpr lambdaExpr)

Description copied from interface: ApplyFunction

Returns true if apply function produces an array output. All ApplyFunction implementations are expected to exclusively produce either scalar or array values.

Specified by:

hasArrayOutput in interface ApplyFunction

apply

public ExprEval apply(org.apache.druid.math.expr.LambdaExpr lambdaExpr,
                      List<Expr> argsExpr,
                      Expr.ObjectBinding bindings)

Description copied from interface: ApplyFunction

Apply LambdaExpr to argument list of Expr given a set of outer Expr.ObjectBinding. These outer bindings will be used to form the scope for the bindings used to evaluate the LambdaExpr, which use the array inputs to supply scalar values to use as bindings for IdentifierExpr in the lambda body.

Specified by:

apply in interface ApplyFunction

getArrayInputs

public Set<Expr> getArrayInputs(List<Expr> args)

Description copied from interface: ApplyFunction

Get list of input arguments which must evaluate to an array ExprType

Specified by:

getArrayInputs in interface ApplyFunction

validateArguments

public void validateArguments(org.apache.druid.math.expr.LambdaExpr lambdaExpr,
                              List<Expr> args)

Description copied from interface: ApplyFunction

Validate function arguments. This method is called whenever a ApplyFunctionExpr is created, and should validate everything that is feasible up front. Note that input type information is typically unavailable at the time Expr are parsed, and so this method is incapable of performing complete validation.

Specified by:

validateArguments in interface ApplyFunction

getOutputType

@Nullable
public ExpressionType getOutputType(Expr.InputBindingInspector inspector,
                                    org.apache.druid.math.expr.LambdaExpr expr,
                                    List<Expr> args)

Description copied from interface: ApplyFunction

Compute the output type of this function for a given lambda and the argument expressions which will be applied as its inputs.

Specified by:

getOutputType in interface ApplyFunction

See Also:

Expr.getOutputType(org.apache.druid.math.expr.Expr.InputBindingInspector)