io.jenetics.prog.op

Interface Op<T>

Type Parameters:

T - the argument type of the operation

All Superinterfaces:

Function<T[],T>, Supplier<Op<T>>

All Known Implementing Classes:

Const, EphemeralConst, MathOp, Program, Var

public interface Op<T>
extends Function<T[],T>, Supplier<Op<T>>

Operation interface. An operation is a function which maps some argument type with a given arity to a result object of the same type: T[] -> T.

final Op<Double> add = Op.of("add", 2, v -> v[0] + v[1]); final Op<Double> add3 = Op.of("add3", 3, v -> v[0] + v[1] + v[2]); final Op<Double> sub = Op.of("sub", 2, v -> v[0] - v[1]); final Op<Double> sin = Op.of("sin", 1, v -> Math.sin(v[0]));

Implementations of the Op interface are usually immutable and doesn't maintain internal state. But some instance are ephemeral with changing state. This classes must override the get() method inherited from the Supplier interface and return a new instance.

Since:

3.9

Version:

3.9

Author:

Franz Wilhelmstötter

See Also:

Var, Const, EphemeralConst

Method Summary

Modifier and Type	Method and Description
int	arity() Return the arity of the operation function.
default Op<T>	get() Return this operation, or a new instance from the same type, if the operation needs to maintain internal state.
default boolean	isTerminal() Determines if the operation is a terminal operation.
String	name() Return the name of the operation.
static <T> Op<T>	of(String name, BinaryOperator<T> function) Create a new operation with the given name and binary operation.
static <T> Op<T>	of(String name, int arity, Function<T[],T> function) Create a new operation from the given parameter.
static <T> Op<T>	of(String name, UnaryOperator<T> function) Create a new operation with the given name and unary operation.

Methods inherited from interface java.util.function.Function

andThen, apply, compose, identity

Method Detail

name

String name()

Return the name of the operation.

Returns:

the name of the operation

arity

int arity()

Return the arity of the operation function. If the arity is zero, the operation is terminal operation.

Returns:

the arity of the operation

isTerminal

default boolean isTerminal()

Determines if the operation is a terminal operation.

Returns:

true if the operation is a terminal operation, false otherwise

get

default Op<T> get()

Return this operation, or a new instance from the same type, if the operation needs to maintain internal state. This is essentially the case for ephemeral constants.

Specified by:

get in interface Supplier<Op<T>>

Returns:

this operation, or a new instance

See Also:

EphemeralConst

of

static <T> Op<T> of(String name,
                    int arity,
                    Function<T[],T> function)

Create a new operation from the given parameter.

Type Parameters:

T - the operation type

Parameters:

name - the operation name

arity - the arity of the operation

function - the function executed by the operation. In order to work properly, the given function should be stateless and must not have side effects.

Returns:

a new operation from the given parameter

Throws:

NullPointerException - if the given name or function is null

IllegalArgumentException - if the given arity is smaller than zero

of

static <T> Op<T> of(String name,
                    UnaryOperator<T> function)

Create a new operation with the given name and unary operation. The returned Op will have arity one.

Type Parameters:

T - the operation type

Parameters:

name - the name of the returned operation

function - the used function of the operation

Returns:

a new operation with the given name and unary operation

Throws:

NullPointerException - if the given name or function is null

Since:

4.0

of

static <T> Op<T> of(String name,
                    BinaryOperator<T> function)

Create a new operation with the given name and binary operation. The returned Op will have arity two.

Type Parameters:

T - the operation type

Parameters:

name - the name of the returned operation

function - the used function of the operation

Returns:

a new operation with the given name and unary operation

Throws:

NullPointerException - if the given name or function is null

Since:

4.0