com.io7m.jequality.annotations.EqualityStructural Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of com.io7m.jequality.core Show documentation

Equality handling (Core)

The newest version!

/*
 * Copyright © 2014 Mark Raynsford  https://www.io7m.com
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR
 * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

package com.io7m.jequality.annotations;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 *  An annotation that, when applied to a given class, implies that the class
 * uses structural equality. That is, for a given type {@code C} with the set of
 * fields {@code F}, {@code ∀x y. x : C ∧ y : C → (∀f. f ∈ F → (x.f.equals(y.f)
 * ↔ x.equals(y)))} . 
 */

@Documented
@Target({ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface EqualityStructural
{
  // Nothing.
}