JavaCollections.java

/*                        __    __  __  __    __  ___
 *                       \  \  /  /    \  \  /  /  __/
 *                        \  \/  /  /\  \  \/  /  /
 *                         \____/__/  \__\____/__/.ɪᴏ
 * ᶜᵒᵖʸʳᶦᵍʰᵗ ᵇʸ ᵛᵃᵛʳ ⁻ ˡᶦᶜᵉⁿˢᵉᵈ ᵘⁿᵈᵉʳ ᵗʰᵉ ᵃᵖᵃᶜʰᵉ ˡᶦᶜᵉⁿˢᵉ ᵛᵉʳˢᶦᵒⁿ ᵗʷᵒ ᵈᵒᵗ ᶻᵉʳᵒ
 */
package io.vavr;

import java.util.*;

final class JavaCollections {

    private JavaCollections() {
    }

    @SuppressWarnings("unchecked")
    static <K, V> Map<K, V> javaMap(Object... pairs) {
        Objects.requireNonNull(pairs, "pairs is null");
        if ((pairs.length & 1) != 0) {
            throw new IllegalArgumentException("Odd length of key-value pairs list");
        }
        final Map<K, V> map = new HashMap<>();
        for (int i = 0; i < pairs.length; i += 2) {
            map.put((K) pairs[i], (V) pairs[i + 1]);
        }
        return map;
    }

    @SuppressWarnings("unchecked")
    static <T> Set<T> javaSet(T... elements) {
        Objects.requireNonNull(elements, "elements is null");
        final Set<T> set = new HashSet<>();
        Collections.addAll(set, elements);
        return set;
    }
}