/*

 * Copyright 1998-2004 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.jdi;

/**

 * A local variable in the target VM. Each variable declared within a

 * {@link Method} has its own LocalVariable object. Variables of the same

 * name declared in different scopes have different LocalVariable objects.

 * LocalVariables can be used alone to retrieve static information

 * about their declaration, or can be used in conjunction with a

 * {@link StackFrame} to set and get values.

 *

 * @see StackFrame

 * @see Method

 *

 * @author Robert Field

 * @author Gordon Hirsch

 * @author James McIlree

 * @since  1.3

 */

public interface LocalVariable extends Mirror, Comparable<LocalVariable> {

    /**

     * Gets the name of the local variable.

     *

     * @return a string containing the name.

     */

    String name();

    /**

     * Returns a text representation of the type

     * of this variable.

     * Where the type is the type specified in the declaration

     * of this local variable.

     * <P>

     * This type name is always available even if

     * the type has not yet been created or loaded.

     *

     * @return a String representing the

     * type of this local variable.

     */

    String typeName();

    /**

     * Returns the type of this variable.

     * Where the type is the type specified in the declaration

     * of this local variable.

     * <P>

     * Note: if the type of this variable is a reference type (class,

     * interface, or array) and it has not been created or loaded

     * by the class loader of the enclosing class,

     * then ClassNotLoadedException will be thrown.

     * Also, a reference type may have been loaded but not yet prepared,

     * in which case the type will be returned

     * but attempts to perform some operations on the returned type

     * (e.g. {@link ReferenceType#fields() fields()}) will throw

     * a {@link ClassNotPreparedException}.

     * Use {@link ReferenceType#isPrepared()} to determine if

     * a reference type is prepared.

     *

     * @see Type

     * @see Field#type() Field.type() - for usage examples

     * @return the {@link Type} of this local variable.

     * @throws ClassNotLoadedException if the type has not yet been loaded

     * through the appropriate class loader.

     */

    Type type() throws ClassNotLoadedException;

    /**

     * Gets the JNI signature of the local variable.

     *

     * @see <a href="doc-files/signature.html">Type Signatures</a>

     * @return a string containing the signature.

     */

    String signature();

    /**

     * Gets the generic signature for this variable if there is one.

     * Generic signatures are described in the

     * <a href="http://java.sun.com/docs/books/vmspec">

     * "Java<sup><font size=-2>TM</font></sup>

     * Virtual Machine Specification, 3rd Edition.</a>

     *

     * @return a string containing the generic signature, or <code>null</code>

     * if there is no generic signature.

     *

     * @since 1.5

     */

    String genericSignature();

    /**

     * Determines whether this variable can be accessed from the given

     * {@link StackFrame}.

     *

     * See {@link StackFrame#visibleVariables} for a complete description

     * variable visibility in this interface.

     *

     * @param frame the StackFrame querying visibility

     * @return <code>true</code> if this variable is visible;

     * <code>false</code> otherwise.

     * @throws IllegalArgumentException if the stack frame's method

     * does not match this variable's method.

     */

    boolean isVisible(StackFrame frame);

    /**

     * Determines if this variable is an argument to its method.

     *

     * @return <code>true</code> if this variable is an argument;

     * <code>false</code> otherwise.

     */

    boolean isArgument();

    /**

     * Compares the specified Object with this LocalVariable for equality.

     *

     * @return  true if the Object is a LocalVariable, if both LocalVariables

     * are contained in the same method (as determined by

     * {@link Method#equals}), and if both LocalVariables mirror

     * the same declaration within that method

     */

    boolean equals(Object obj);

    /**

     * Returns the hash code value for this LocalVariable.

     *

     * @return the integer hash code

     */

    int hashCode();

}