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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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 *
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package com.oracle.truffle.api.instrument;

import com.oracle.truffle.api.nodes.*;

/**
 * A node that can be inserted into a Truffle AST in order to attach <em>instrumentation</em> at a
 * particular node.
 * <p>
 * A wrapper <em>decorates</em> an AST node (its <em>child</em>) by acting as a transparent
 * <em>proxy</em> for the child with respect to Truffle execution semantics.
 * <p>
 * A wrapper is also expected to notify its associated {@link Probe} when certain
 * {@link ExecutionEvents} occur at the wrapper during program execution.
 * <p>
 * The wrapper's {@link Probe} is shared by every copy of the wrapper made when the AST is copied.
 * <p>
 * Wrappers methods must be amenable to Truffle/Graal inlining.
 * <p>
 * <strong>Disclaimer:</strong> experimental interface under development.
 */
public interface Wrapper extends PhylumTagged {

    /**
     * Gets the AST node being instrumented, which should never be an instance of {@link Wrapper}.
     */
    Node getChild();

    /**
     * Gets the {@link Probe} to which events occurring at this wrapper's child are propagated.
     */
    Probe getProbe();

}