com.yahoo.tensor.functions.ScalarFunction Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of vespajlib Show documentation

Library for use in Java components of Vespa. Shared code which do not fit anywhere else.

There is a newer version: 8.441.21

// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
package com.yahoo.tensor.functions;

import com.yahoo.tensor.evaluation.EvaluationContext;
import com.yahoo.tensor.evaluation.Name;

import java.util.Optional;
import java.util.function.Function;

/**
 * A function which returns a scalar
 *
 * @author bratseth
 */
public interface ScalarFunction extends Function, Double> {

    @Override
    Double apply(EvaluationContext context);

    /** Returns this as a tensor function, or empty if it cannot be represented as a tensor function */
    default Optional> asTensorFunction() { return Optional.empty(); }

    default String toString(ToStringContext context) { return toString(); }

}