/interpreter/tags/at2-build270707/src/edu/vub/at/objects/ATField.java
Java | 69 lines | 8 code | 6 blank | 55 comment | 0 complexity | 3de758edaa3bc708b258d768f789eaf9 MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * ATField.java created on Jul 23, 2006 at 11:52:56 AM 4 * (c) Programming Technology Lab, 2006 - 2007 5 * Authors: Tom Van Cutsem & Stijn Mostinckx 6 * 7 * Permission is hereby granted, free of charge, to any person 8 * obtaining a copy of this software and associated documentation 9 * files (the "Software"), to deal in the Software without 10 * restriction, including without limitation the rights to use, 11 * copy, modify, merge, publish, distribute, sublicense, and/or 12 * sell copies of the Software, and to permit persons to whom the 13 * Software is furnished to do so, subject to the following 14 * conditions: 15 * 16 * The above copyright notice and this permission notice shall be 17 * included in all copies or substantial portions of the Software. 18 * 19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 21 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 23 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 24 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 25 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 26 * OTHER DEALINGS IN THE SOFTWARE. 27 */ 28package edu.vub.at.objects; 29 30import edu.vub.at.exceptions.InterpreterException; 31import edu.vub.at.objects.grammar.ATSymbol; 32 33/** 34 * ATField provides a mapping from an immutable name to a potentially mutable value. 35 * <p> 36 * Note that when field objects are added to an {@link ATObject} and then that object is cloned, 37 * the field object will be re-instantiated (i.e. its 'new' method is invoked). 38 * This implies that any object implementing ATField should provide a meta_newInstance 39 * method whose sole initarg is the new host for the field. 40 * 41 * @author smostinc 42 */ 43public interface ATField extends ATObject { 44 45 /** 46 * Returns a string by which the slot can be identified. 47 * 48 * @return a {@link ATSymbol} representing the string by which the slot can be identified. 49 */ 50 public ATSymbol base_name() throws InterpreterException; 51 52 /** 53 * Returns the current value of the field. 54 * 55 * @return an {@link ATObject} representing the current value of the field. 56 * @throws XIllegalOperation if the field accessed is not found. 57 */ 58 public ATObject base_readField() throws InterpreterException; 59 60 /** 61 * Sets the value of the field if possible. 62 * 63 * @param newValue the value the field should hold. 64 * @return by default, the new value 65 * @throws InterpreterException if the field cannot be modified. 66 */ 67 public ATObject base_writeField(ATObject newValue) throws InterpreterException; 68 69}