/interpreter/tags/at2dist170907/src/edu/vub/at/objects/natives/NATFieldSelection.java

  1/**
  2 * AmbientTalk/2 Project
  3 * NATFieldSelection.java created on 31-jul-2006 at 12:40:42
  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.eval.Evaluator;
 31import edu.vub.at.exceptions.InterpreterException;
 32import edu.vub.at.objects.ATFieldSelection;
 33import edu.vub.at.objects.ATMessage;
 34import edu.vub.at.objects.ATMethodInvocation;
 35import edu.vub.at.objects.ATObject;
 36import edu.vub.at.objects.ATTypeTag;
 37import edu.vub.at.objects.ATTable;
 38import edu.vub.at.objects.coercion.NativeTypeTags;
 39import edu.vub.at.objects.grammar.ATSymbol;
 40
 41import java.util.LinkedList;
 42import java.util.Vector;
 43
 44/**
 45 * Instances of this class represent first-class field selections.
 46 * They encapsulate a selector and may be turned into an actual field access by invoking meta_sendTo.
 47 * This method provides the invocation with a receiver to apply itself to.
 48 * 
 49 * @author tvcutsem
 50 */
 51public final class NATFieldSelection extends NATMessage implements ATFieldSelection {
 52
 53	public NATFieldSelection(ATSymbol sel, ATTable annotations) throws InterpreterException {
 54		super(sel, NATTable.EMPTY, annotations, NativeTypeTags._FIELDSEL_);
 55	}
 56	
 57    /**
 58     * Copy constructor.
 59     */
 60    private NATFieldSelection(FieldMap map,
 61            Vector state,
 62            LinkedList originalCustomFields,
 63            MethodDictionary methodDict,
 64            ATObject dynamicParent,
 65            ATObject lexicalParent,
 66            byte flags,
 67            ATTypeTag[] types) throws InterpreterException {
 68    	super(map, state, originalCustomFields, methodDict, dynamicParent, lexicalParent, flags, types);
 69    }
 70
 71	/**
 72	 * To evaluate a field selection, invoke a field accessor method on the receiver.
 73	 * 
 74	 * @return the return value of the invoked method.
 75	 */
 76	public ATObject prim_sendTo(ATMessage self, ATObject receiver, ATObject sender) throws InterpreterException {
 77		return receiver.meta_invokeField(receiver, self.base_selector());
 78	}
 79	
 80	public NATText meta_print() throws InterpreterException {
 81		return NATText.atValue("<field selection:"+base_selector().toString()+">");
 82	}
 83	
 84	protected NATObject createClone(FieldMap map,
 85			Vector state,
 86			LinkedList originalCustomFields,
 87			MethodDictionary methodDict,
 88			ATObject dynamicParent,
 89			ATObject lexicalParent,
 90			byte flags,
 91			ATTypeTag[] types) throws InterpreterException {
 92		return new NATFieldSelection(map,
 93				state,
 94				originalCustomFields,
 95				methodDict,
 96				dynamicParent,
 97				lexicalParent,
 98				flags,
 99				types);
100	}
101	
102}