Akka/Scala example source code file (Match.java)

This example Akka source code file (Match.java) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Akka and Scala source code examples by using tags.

All credit for the original source code belongs to akka.io; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Akka tags/keywords

abstractmatch, akka, class, f, japi, match, matcherror, p, pfbuilder, r, t

The Match.java Akka example source code

/**
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */

package akka.japi.pf;

import scala.MatchError;
import scala.PartialFunction;

/**
 * Version of {@link scala.PartialFunction} that can be built during
 * runtime from Java.
 *
 * @param <I> the input type, that this PartialFunction will be applied to
 * @param <R> the return type, that the results of the application will have
 *
 * This is an EXPERIMENTAL feature and is subject to change until it has received more real world testing.
 */
public class Match<I, R> extends AbstractMatch<I, R> {

  /**
   * Convenience function to create a {@link PFBuilder} with the first
   * case statement added.
   *
   * @param type   a type to match the argument against
   * @param apply  an action to apply to the argument if the type matches
   * @return       a builder with the case statement added
   * @see PFBuilder#match(Class, FI.Apply)
   */
  public static final <F, T, P> PFBuilder<F, T> match(final Class<P> type,
                                                      final FI.Apply<P, T> apply) {
    return new PFBuilder<F, T>().match(type, apply);
  }

  /**
   * Convenience function to create a {@link PFBuilder} with the first
   * case statement added.
   *
   * @param type       a type to match the argument against
   * @param predicate  a predicate that will be evaluated on the argument if the type matches
   * @param apply      an action to apply to the argument if the type matches
   * @return           a builder with the case statement added
   * @see PFBuilder#match(Class, FI.TypedPredicate, FI.Apply)
   */
  public static <F, T, P> PFBuilder<F, T> match(final Class<P> type,
                                                final FI.TypedPredicate<P> predicate,
                                                final FI.Apply<P, T> apply) {
    return new PFBuilder<F, T>().match(type, predicate, apply);
  }

  /**
   * Convenience function to create a {@link PFBuilder} with the first
   * case statement added.
   *
   * @param object  the object to compare equals with
   * @param apply  an action to apply to the argument if the object compares equal
   * @return a builder with the case statement added
   * @see PFBuilder#matchEquals(Object, FI.Apply)
   */
  public static <F, T, P> PFBuilder<F, T> matchEquals(final P object,
                                                      final FI.Apply<P, T> apply) {
    return new PFBuilder<F, T>().matchEquals(object, apply);
  }

  /**
   * Convenience function to create a {@link PFBuilder} with the first
   * case statement added.
   *
   * @param apply  an action to apply to the argument
   * @return a builder with the case statement added
   * @see PFBuilder#matchAny(FI.Apply)
   */
  public static <F, T> PFBuilder<F, T> matchAny(final FI.Apply<Object, T> apply) {
    return new PFBuilder<F, T>().matchAny(apply);
  }

  /**
   * Create a {@link Match} from the builder.
   *
   * @param builder  a builder representing the partial function
   * @return         a {@link Match} that can be reused
   */
  public static final <F, T> Match<F, T> create(PFBuilder<F, T> builder) {
    return new Match<F, T>(builder.build());
  }

  Match(PartialFunction<I, R> statements) {
    super(statements);
  }

  /**
   * Convenience function to make the Java code more readable.
   *
   * <pre><code>
   *   Matcher<X, Y> matcher = Matcher.create(...);
   *
   *   Y someY = matcher.match(obj);
   * </code></pre>
   *
   * @param i  the argument to apply the match to
   * @return   the result of the application
   * @throws MatchError  if there is no match
   */
  public R match(I i) throws MatchError {
    return statements.apply(i);
  }
}