/interpreter/tags/at2-build190607/src/edu/vub/at/objects/natives/grammar/AGAssignField.java

 1/**
 2 * AmbientTalk/2 Project
 3 * AGAssignField.java created on 17-aug-2006 at 13:45:32
 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;
33import edu.vub.at.objects.grammar.ATAssignField;
34import edu.vub.at.objects.grammar.ATExpression;
35import edu.vub.at.objects.grammar.ATSymbol;
36import edu.vub.at.objects.natives.NATText;
37
38/**
39 * The native implementation of a field assignment AG element.
40 *  
41 *  @author tvc
42 */
43public final class AGAssignField extends NATAbstractGrammar implements ATAssignField {
44
45	private final ATExpression rcvExp_;
46	private final ATSymbol fieldName_;
47	private final ATExpression valueExp_;
48	
49	public AGAssignField(ATExpression rcv, ATSymbol nam, ATExpression val) {
50		rcvExp_ = rcv;
51		fieldName_ = nam;
52		valueExp_ = val;
53	}
54	
55	public ATExpression base_getReceiverExpression() { return rcvExp_; }
56	
57	public ATSymbol base_getFieldName() { return fieldName_; }
58
59	public ATExpression base_getValueExpression() { return valueExp_; }
60	
61	/**
62	 * To evaluate a field assignment, evaluate the receiver expression, evaluate the right hand side and ask
63	 * the receiver object to assign the RHS value to the field corresponding to the given field name.
64	 * 
65	 * AGASSFIELD(rcv,nam,val).eval(ctx) = rcv.eval(ctx).assignField(nam, val.eval(ctx))
66	 * 
67	 * @return the new value of the field
68	 */
69	public ATObject meta_eval(ATContext ctx) throws InterpreterException {
70		ATObject receiver = rcvExp_.meta_eval(ctx);
71		ATObject val = valueExp_.meta_eval(ctx);
72		receiver.meta_assignField(receiver, fieldName_, val);
73		return val;
74	}
75
76	/**
77	 * AGASSFIELD(rcv,nam,val).quote(ctx) = AGASSFIELD(rcv.quote(ctx), nam.quote(ctx), val.quote(ctx))
78	 */
79	public ATObject meta_quote(ATContext ctx) throws InterpreterException {
80		return new AGAssignField(rcvExp_.meta_quote(ctx).asExpression(), fieldName_.meta_quote(ctx).asSymbol(), valueExp_.meta_quote(ctx).asExpression());
81	}
82	
83	public NATText meta_print() throws InterpreterException {
84		return NATText.atValue(rcvExp_.meta_print().javaValue + "." + fieldName_.meta_print().javaValue + " := " + valueExp_.meta_print().javaValue);
85	}
86
87}