/interpreter/tags/at2-build190607/src/edu/vub/at/objects/natives/grammar/AGSelf.java
Java | 70 lines | 18 code | 9 blank | 43 comment | 0 complexity | 6d767507d4ae3eddb004768440e0318f MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * AGSelf.java created on 27-jul-2006 at 12:57:41 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.natives.grammar; 29 30import edu.vub.at.exceptions.InterpreterException; 31import edu.vub.at.objects.ATContext; 32import edu.vub.at.objects.ATObject; 33 34/** 35 * @author tvc 36 * 37 * The abstract grammar element denoting the symbol 'self' 38 */ 39public final class AGSelf extends AGSymbol { 40 41 private static final String SELF_NAM = "self"; 42 43 public static final AGSelf _INSTANCE_ = new AGSelf(); 44 45 private AGSelf() { super(SELF_NAM); } 46 47 /** 48 * To evaluate a self reference, simply select the current self from the current evaluation context. 49 * 50 * AGSelf().eval(ctx) = ctx.self 51 */ 52 public ATObject meta_eval(ATContext ctx) throws InterpreterException { 53 return ctx.base_getSelf(); 54 } 55 56 /** 57 * Quoting a self reference results in the same self reference. 58 */ 59 public ATObject meta_quote(ATContext ctx) { 60 return this; 61 } 62 63 /** 64 * After deserialization, ensure that the self pseudovariable remains unique. 65 */ 66 public ATObject meta_resolve() throws InterpreterException { 67 return _INSTANCE_; 68 } 69 70}