Module org.scijava.ops.tutorial

Package org.scijava.ops.tutorial

Class OpReduction

java.lang.Object

org.scijava.ops.tutorial.OpReduction

public class OpReduction
extends Object

One powerful feature of SciJava Ops is the ability to transform individual Ops to match user requests. In this way, SciJava Ops can satisfy many Op calls with just one implementation.

Another transformation is called "reduction". This type of transformation allows marked "Nullable" parameters to be omitted from Op requests, in a right-to-left order. For example, if the rightmost parameter to an Op is marked as Nullable, then it can be provided, or omitted, in Op signatures. If the rightmost two parameters are both marked as Nullable, then both can be provided, both can be omitted, or only the rightmost parameter can be omitted.

Within Ops declaring Nullable parameters, omitted parameters are given null arguments. The Op is thus responsible for null-checking any parameters it declares as Nullable.

Below, we can see how this works by calling the above Method Op, normally requiring three parameters, with only two parameters.

Constructor Summary

Constructors

Constructor	Description
OpReduction()

Method Summary

Modifier and Type	Method	Description
static void	main(String... args)
static Double	nullableMethod(Double in1, Double in2, Double in3)	An Method annotated to be an Op.

Methods inherited from class java.lang.Object

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

Constructor Detail

OpReduction

public OpReduction()

Method Detail

nullableMethod

public static Double nullableMethod(Double in1,
                                    Double in2,
                                    Double in3)

An Method annotated to be an Op.

Parameters:

in1 - the first input

in2 - the second input. OPTIONAL.

in3 - the third input. OPTIONAL.

Returns:

the sum of the passed numbers.

Implementation Note:

op names="tutorial.reduce"

main

public static void main(String... args)