Package com.singularsys.extensions.lambda

Class Reduce

java.lang.Object

com.singularsys.jep.functions.PostfixMathCommand

com.singularsys.jep.functions.NaryFunction

com.singularsys.extensions.lambda.Reduce

All Implemented Interfaces:

JepComponent, PostfixMathCommandI, Serializable

public class Reduce
extends NaryFunction
implements JepComponent

Reduce a list, using an identity value and a lambda function defining the reduction operation.

 Sum = [x,y]=>x+y
 reduce(0, Sum, [1,2,3,4,5])
 

This is similar to the Fold function, but will work with empty lists, in which case the identity value is returned.

Since:

Jep 4.1, extensions 2.2

See Also:

• Serialized Form

Field Summary

Fields inherited from class com.singularsys.jep.functions.PostfixMathCommand

curNumberOfParameters, description, name, NaN, numberOfParameters

Constructor Summary

Constructors

Constructor	Description
Reduce()

Method Summary

Modifier and Type	Method	Description
Object	eval(Object[] args)	Evaluate the function
JepComponent	getLightWeightInstance()	Gets a light-weight instance suitable for using in multiple threads.
void	init(Jep jep)	Initialize the component.

Methods inherited from class com.singularsys.jep.functions.NaryFunction

run

Methods inherited from class com.singularsys.jep.functions.PostfixMathCommand

asArray, asBool, asDouble, asInt, asLong, asStrictInt, asString, asType, checkNumberOfParameters, getDescription, getDescription, getDescriptionWithType, getName, getNumberOfParameters, setCurNumberOfParameters, setDescription, setName, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Details

Reduce

public Reduce()

Method Details

eval

public Object eval(Object[] args)
            throws EvaluationException

Description copied from class: NaryFunction

Evaluate the function

Specified by:

eval in class NaryFunction

Parameters:

args - arguments to the function

Returns:

value returned by the function

Throws:

EvaluationException - if the calculation cannot be performed

init

public void init(Jep jep)

Description copied from interface: JepComponent

Initialize the component. This method is called whenever a component is added to Jep. Hence, it allows components to keep track of the other components they may rely on.

Specified by:

init in interface JepComponent

Parameters:

jep - the current Jep instance

getLightWeightInstance

public JepComponent getLightWeightInstance()

Description copied from interface: JepComponent

Gets a light-weight instance suitable for using in multiple threads.

Specified by:

getLightWeightInstance in interface JepComponent

Returns:

either a new instance, null or 'this'.