/*
* Copyright (c) 2012, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.oracle.truffle.api.dsl;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Overrides the standard way of checking for a certain type in a {@link TypeSystem}. This is useful
* for types where the guest language specific type check can be implemented more efficiently than
* an instanceof check. The annotated method must be contained in a {@link TypeSystem} annotated
* class. Type checks must conform to the following signature:
* <code>public static boolean is{TypeName}(Object
* value)</code>. The checked type must be a type declared in the {@link TypeSystem}.
*
* <p>
* If no {@link TypeCheck} is declared then the type system implicitly uses a type check that can be
* declared as follows:
*
* <pre>
* {@literal @}TypeCheck(Type.class)
* public static boolean isType(Object value) {
* return value instanceof Type;
* }
* </pre>
*
* @see TypeCast
* @since 0.8 or earlier
*/
@Retention(RetentionPolicy.CLASS)
@Target({ElementType.METHOD})
public @interface TypeCheck {
Class<?> value();
}