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/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// API class

package org.mozilla.javascript;

public interface ConstProperties {
    /**
     * Sets a named const property in this object.
     * 
     * The property is specified by a string name
     * as defined for Scriptable.get.
     * 

     * The possible values that may be passed in are as defined for
     * Scriptable.get. A class that implements this method may choose
     * to ignore calls to set certain properties, in which case those
     * properties are effectively read-only.

     * For properties defined in a prototype chain,
     * use putProperty in ScriptableObject. 

     * Note that if a property a is defined in the prototype p
     * of an object o, then evaluating o.a = 23 will cause
     * set to be called on the prototype p with
     * o as the  start parameter.
     * To preserve JavaScript semantics, it is the Scriptable
     * object's responsibility to modify o. 

     * This design allows properties to be defined in prototypes and implemented
     * in terms of getters and setters of Java values without consuming slots
     * in each instance.

     * 

     * The values that may be set are limited to the following:
     * 

     * java.lang.Boolean objects
     * java.lang.String objects
     * java.lang.Number objects
     * org.mozilla.javascript.Scriptable objects
     * null
     * The value returned by Context.getUndefinedValue()
     * 

     * Arbitrary Java objects may be wrapped in a Scriptable by first calling
     * Context.toObject. This allows the property of a JavaScript
     * object to contain an arbitrary Java object as a value.
     * Note that has will be called by the runtime first before
     * set is called to determine in which object the
     * property is defined.
     * Note that this method is not expected to traverse the prototype chain,
     * which is different from the ECMA [[Put]] operation.
     * @param name the name of the property
     * @param start the object whose property is being set
     * @param value value to set the property to
     * @see org.mozilla.javascript.Scriptable#has(String, Scriptable)
     * @see org.mozilla.javascript.Scriptable#get(String, Scriptable)
     * @see org.mozilla.javascript.ScriptableObject#putProperty(Scriptable, String, Object)
     * @see org.mozilla.javascript.Context#toObject(Object, Scriptable)
     */
    public void putConst(String name, Scriptable start, Object value);

    /**
     * Reserves a definition spot for a const.  This will set up a definition
     * of the const property, but set its value to undefined.  The semantics of
     * the start parameter is the same as for putConst.
     * @param name The name of the property.
     * @param start The object whose property is being reserved.
     */
    public void defineConst(String name, Scriptable start);

    /**
     * Returns true if the named property is defined as a const on this object.
     * @param name
     * @return true if the named property is defined as a const, false
     * otherwise.
     */
    public boolean isConst(String name);
}