Class CompositionPredicate

output/java_guava/1.4.17/Predicates.java:650–684

@see Predicates#compose(Predicate, Function)

  /** @see Predicates#compose(Predicate, Function) */

  private static class CompositionPredicate<A, B> implements Predicate<A>, Serializable {
    final Predicate<B> p;
    final Function<A, ? extends B> f;
    private CompositionPredicate(Predicate<B> p, Function<A, ? extends B> f) {
      this.p = checkNotNull(p);
      this.f = checkNotNull(f);
    }

    @Override
    public boolean apply(@Nullable A a) {
      return p.apply(f.apply(a));
    }

    @Override
    public boolean equals(@Nullable Object obj) {
      if (obj instanceof CompositionPredicate) {
        CompositionPredicate<?, ?> that = (CompositionPredicate<?, ?>) obj;
        return f.equals(that.f) && p.equals(that.p);
      }
      return false;
    }

    @Override
    public int hashCode() {
      return f.hashCode() ^ p.hashCode();
    }

    @Override
    public String toString() {
      // TODO(cpovirk): maybe make this look like the method call does ("Predicates.compose(...)")
      return p + "(" + f + ")";
    }

    private static final long serialVersionUID = 0;
  }

  /** @see Predicates#contains(Pattern) */