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Functional patterns for Java

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package com.jnape.palatable.lambda.functions.builtin.fn3;

import com.jnape.palatable.lambda.functions.Fn1;
import com.jnape.palatable.lambda.functions.Fn2;
import com.jnape.palatable.lambda.functions.Fn3;

import static com.jnape.palatable.lambda.functions.builtin.fn2.Replicate.replicate;
import static com.jnape.palatable.lambda.functions.builtin.fn3.FoldLeft.foldLeft;

/**
 * Given some number of times n to invoke a function A -> A, and given an input
 * A, iteratively apply the function to the input, and then to the result of the invocation, a total of
 * n times, returning the result.
 * 
 * Example:
 *
 * times(3, x -> x + 1, 0); // 3
 *
 * @param  the input and output type
 */
public final class Times implements Fn3, A, A> {

    private static final Times INSTANCE = new Times<>();

    private Times() {
    }

    @Override
    public A checkedApply(Integer n, Fn1 fn, A a) {
        if (n < 0)
            throw new IllegalStateException("n must not be less than 0");

        return foldLeft((acc, f) -> f.apply(acc), a, replicate(n, fn));
    }

    @SuppressWarnings("unchecked")
    public static  Times times() {
        return (Times) INSTANCE;
    }

    public static  Fn2, A, A> times(Integer n) {
        return Times.times().apply(n);
    }

    public static  Fn1 times(Integer n, Fn1 fn) {
        return Times.times(n).apply(fn);
    }

    public static  A times(Integer n, Fn1 fn, A a) {
        return Times.times(n, fn).apply(a);
    }
}