com.jnape.palatable.lambda.functions.specialized.Predicate Maven / Gradle / Ivy

Go to download

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

Functional patterns for Java

There is a newer version: 5.5.0

package com.jnape.palatable.lambda.functions.specialized;

import com.jnape.palatable.lambda.functions.Fn1;

import java.util.function.Function;

/**
 * A specialized {@link Fn1} that returns a Boolean.
 *
 * @param  The argument type
 */
public interface Predicate extends Fn1, java.util.function.Predicate {

    /**
     * {@inheritDoc}
     */
    @Override
    default boolean test(A a) {
        return apply(a);
    }

    /**
     * Override of {@link Function#compose(Function)}, returning an instance of Predicate for
     * compatibility. Right-to-left composition.
     *
     * @param before the function who's return value is this predicate's argument
     * @param     the new argument type
     * @return a new predicate of Z (the new argument type)
     */
    @Override
    @SuppressWarnings("unchecked")
    default  Predicate compose(Function before) {
        return Fn1.super.compose(before)::apply;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    @SuppressWarnings("unchecked")
    default  Predicate diMapL(Fn1 fn) {
        return Fn1.super.diMapL(fn)::apply;
    }

    /**
     * Override of {@link java.util.function.Predicate#and(java.util.function.Predicate)}, returning an instance of
     * Predicate for compatibility. Left-to-right composition.
     *
     * @param other the predicate to test if this one succeeds
     * @return a predicate representing the conjunction of this predicate and other
     */
    @Override
    default Predicate and(java.util.function.Predicate other) {
        return a -> apply(a) && other.test(a);
    }

    /**
     * Override of {@link java.util.function.Predicate#or(java.util.function.Predicate)}, returning an instance of
     * Predicate for compatibility. Left-to-right composition.
     *
     * @param other the predicate to test if this one fails
     * @return a predicate representing the disjunction of this predicate and other
     */
    @Override
    default Predicate or(java.util.function.Predicate other) {
        return a -> apply(a) || other.test(a);
    }

    /**
     * Override of {@link java.util.function.Predicate#negate()}, returning an instance of Predicate for
     * compatibility.
     *
     * @return the negation of this predicate
     */
    @Override
    default Predicate negate() {
        return a -> !apply(a);
    }
}