/interpreter/tags/at2-build060407/src/edu/vub/at/objects/natives/NATContext.java

 1/**
 2 * AmbientTalk/2 Project
 3 * NATContext.java created on Jul 24, 2006 at 11:22:36 PM
 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;
29
30import edu.vub.at.exceptions.InterpreterException;
31import edu.vub.at.objects.ATContext;
32import edu.vub.at.objects.ATObject;
33import edu.vub.at.objects.ATTable;
34import edu.vub.at.objects.coercion.NativeStripes;
35
36/**
37 * NATContext is a purely functional implementation of the ATContext interface.
38 * It allows for storing the context parameters (scope self super) in such a way 
39 * that no ill-placed assignment may affect other frames on the stack.
40 * 
41 * @author smostinc
42 */
43public class NATContext extends NATByCopy implements ATContext {
44
45	private final ATObject scope_;
46	private final ATObject self_;
47	
48	public NATContext(ATObject scope, ATObject self) {
49		scope_ = scope;
50		self_ = self;
51	}
52
53	public ATObject base_getLexicalScope() {
54		return scope_;
55	}
56
57	public ATObject base_getSelf() {
58		return self_;
59	}
60
61	public ATContext base_withLexicalEnvironment(ATObject scope) {
62		return new NATContext(scope, self_);
63	}
64	
65	public ATContext base_withDynamicReceiver(ATObject self) {
66		return new NATContext(scope_, self);		
67	}
68	
69	public NATText meta_print() throws InterpreterException {
70		return NATText.atValue("<context("+scope_.meta_print().javaValue+
71				                      ","+self_.meta_print().javaValue+")>");
72	}
73	
74    public ATTable meta_getStripes() throws InterpreterException {
75    	return NATTable.of(NativeStripes._CONTEXT_);
76    }
77    
78	public ATObject meta_clone() throws InterpreterException {
79		return this;
80	}
81
82}