com.github.lokic.javaext.Functions Maven / Gradle / Ivy

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package com.github.lokic.javaext;

import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.BiFunction;
import java.util.function.Function;

public class Functions {

    /**
     * 在某些遍历的场景，可以通过该方法，在 {@code biFunction} 中拿到遍历的下标
     *
     * {@code
     *     List(...)
     *      .stream()
     *      .map(Functions.mapWithIndex((index, item) -> {
     *          ...
     *      })
     * }
     */
    public static  Function mapWithIndex(BiFunction biFunction) {
        AtomicInteger i = new AtomicInteger();
        return t -> biFunction.apply(i.getAndIncrement(), t);
    }
}