Package 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:
    BoolOp, Const, EphemeralConst, MathOp, Program, Val, 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

      All Methods Static Methods Instance Methods Abstract Methods Default Methods 
      Modifier and Type Method 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, int arity, Function<T[],​T> function)
      Create a new operation from the given parameter.
      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, UnaryOperator<T> function)
      Create a new operation with the given name and unary operation.

    • 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<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