Matcher.java

/*  Copyright (c) 2000-2006 hamcrest.org
 */
package mockit.external.hamcrest;

/**
 * A matcher over acceptable values.
 * A matcher is able to describe itself to give feedback when it fails.
 * <p/>
 * Matcher implementations should <b>NOT directly implement this interface</b>.
 * Instead, <b>extend</b> the {@link BaseMatcher} abstract class,
 * which will ensure that the Matcher API can grow to support
 * new features and remain compatible with all Matcher implementations.
 *
 * @see BaseMatcher
 */
public interface Matcher<T> extends SelfDescribing
{
   /**
    * Evaluates the matcher for argument <var>item</var>.
    * <p/>
    * This method matches against Object, instead of the generic type T. This is
    * because the caller of the Matcher does not know at runtime what the type is
    * (because of type erasure with Java generics). It is down to the implementations
    * to check the correct type.
    *
    * @param item the object against which the matcher is evaluated.
    * @return <code>true</code> if <var>item</var> matches, otherwise <code>false</code>.
    * @see BaseMatcher
    */
   boolean matches(Object item);

   /**
    * Generate a description of why the matcher has not accepted the item.
    * The description will be part of a larger description of why a matching
    * failed, so it should be concise.
    * This method assumes that <code>matches(item)</code> is false, but
    * will not check this.
    *
    * @param item                The item that the Matcher has rejected.
    * @param mismatchDescription The description to be built or appended to.
    */
   void describeMismatch(Object item, Description mismatchDescription);
}