TPredicate.java

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/**
 * Determines if the input object matches some criteria.
 *
 * <p>All predicate implementations are expected to:
 * <ul>
 *  <li>Provide stable results such that for any {@code t} the result of two
 * {@code eval} operations are always equivalent. ie.<pre>
 * boolean one = predicate.test(a);
 * boolean two = predicate.test(a);
 *
 * assert one == two;
 * </pre></li>
 * <li>Equivalent input objects should map to equivalent output objects. ie.<pre>
 * assert a.equals(b);  // a and b are equivalent
 *
 * boolean x = predicate.test(a);
 * boolean y = predicate.test(ab;
 *
 * assert x == y; // their test results should be the same.
 * </pre></li>
 * <li>The predicate should not modify the input object in any way that would
 * change the evaluation.</li>
 * <li>When used for aggregate operations upon many elements predicates
 * should not assume that the {@code test} operation will be called upon
 * elements in any specific order.</li>
 * </ul>
 *
 * @param <T> the type of input objects provided to {@code test}.
 */
public interface TPredicate<T> {

    /**
     * Return {@code true} if the input object matches some criteria.
     *
     * @param t the input object.
     * @return {@code true} if the input object matched some criteria.
     */
     boolean test(T t);
}