/interpreter/tags/at2-build270707/src/edu/vub/at/objects/natives/NATMessage.java

  1/**
  2 * AmbientTalk/2 Project
  3 * NATMessage.java created on 31-jul-2006 at 12:31:31
  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.exceptions.XArityMismatch;
 32import edu.vub.at.objects.ATContext;
 33import edu.vub.at.objects.ATMessage;
 34import edu.vub.at.objects.ATNil;
 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;
 40import edu.vub.at.objects.mirrors.PrimitiveMethod;
 41import edu.vub.at.objects.natives.grammar.AGSymbol;
 42
 43import java.util.LinkedList;
 44import java.util.Vector;
 45
 46/**
 47 * Instances of this class represent first-class messages.
 48 * This is an abstract class, as it can be either a synchronous method invocation or an asynchronous message send.
 49 * 
 50 * This class is a subclass of {@link NATObject}, such that its instances represent true AmbientTalk objects.
 51 * 
 52 * @author tvcutsem
 53 */
 54public abstract class NATMessage extends NATObject implements ATMessage {
 55	
 56	private final static AGSymbol _SELECTOR_ = AGSymbol.jAlloc("selector");
 57	private final static AGSymbol _ARGUMENTS_ = AGSymbol.jAlloc("arguments");
 58	
 59	/** def sendTo(receiver, sender) { nil } */
 60	private static final PrimitiveMethod _PRIM_SND_ = new PrimitiveMethod(        
 61			AGSymbol.jAlloc("sendTo"), NATTable.atValue(new ATObject[] { AGSymbol.jAlloc("receiver"), AGSymbol.jAlloc("sender") })) {
 62      private static final long serialVersionUID = -3475956316807558583L;
 63
 64      public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
 65			int arity = arguments.base_length().asNativeNumber().javaValue;
 66			if (arity != 2) {
 67				throw new XArityMismatch("sendTo", 2, arity);
 68			}
 69			return ctx.base_lexicalScope().asMessage().prim_sendTo(
 70					ctx.base_self().asMessage(),
 71					arguments.base_at(NATNumber.ONE), arguments.base_at(NATNumber.atValue(2)));
 72		}
 73	};
 74	
 75	
 76    /**
 77     * Converts the given table of annotations into an ATTypeTag array.
 78     * Each element of the annotations table is converted into a type.
 79     * Moreover, because messages are isolates, the Isolate type is automatically appended to the resulting array.
 80     * Also, each type of message has its own type of type, so a subtype of Message is also added.
 81     */
 82    protected static ATTypeTag[] annotationsToTypes(ATTypeTag msgType, ATTable annotations) throws InterpreterException {
 83		if (annotations == NATTable.EMPTY) {
 84			return new ATTypeTag[] { NativeTypeTags._ISOLATE_, msgType };
 85		}
 86    	
 87        ATObject[] unwrapped = annotations.asNativeTable().elements_;
 88		ATTypeTag[] fulltypes = new ATTypeTag[unwrapped.length+2];
 89		for (int i = 0; i < unwrapped.length; i++) {
 90			fulltypes[i] = unwrapped[i].asTypeTag();
 91		}
 92		fulltypes[unwrapped.length] = NativeTypeTags._ISOLATE_;
 93		fulltypes[unwrapped.length+1] = msgType;
 94        return fulltypes;
 95    }
 96	
 97	/**
 98	 * Construct a new message from the given selector, arguments and annotations.
 99	 * The annotations become this message's types.
100	 * 
101	 * @param annotations a table of objects that should be convertible to types
102	 * @param msgType a subtype of the Message type, added by subclasses to mark which kind of native message is created
103	 */
104	protected NATMessage(ATSymbol sel, ATTable arg, ATTable annotations, ATTypeTag msgType) throws InterpreterException {
105		super(annotationsToTypes(msgType, annotations));
106		super.meta_defineField(_SELECTOR_, sel);
107		super.meta_defineField(_ARGUMENTS_, arg);
108		super.meta_addMethod(_PRIM_SND_);
109	}
110
111    /**
112     * Copy constructor.
113     */
114    protected NATMessage(FieldMap map,
115            Vector state,
116            LinkedList originalCustomFields,
117            MethodDictionary methodDict,
118            ATObject dynamicParent,
119            ATObject lexicalParent,
120            byte flags,
121            ATTypeTag[] types) throws InterpreterException {
122    	super(map, state, originalCustomFields, methodDict, dynamicParent, lexicalParent, flags, types);
123    }
124	
125	public ATSymbol base_selector() throws InterpreterException {
126		return super.meta_invokeField(this, _SELECTOR_).asSymbol();
127	}
128
129	public ATTable base_arguments() throws InterpreterException {
130		return super.meta_invokeField(this, _ARGUMENTS_).asTable();
131	}
132	
133	public ATNil base_arguments__opeql_(ATTable arguments) throws InterpreterException {
134		super.impl_invokeMutator(this, _ARGUMENTS_.asAssignmentSymbol(), NATTable.of(arguments));
135		return OBJNil._INSTANCE_;
136	}
137	
138	/**
139	 * If sendTo is invoked from the Java-level directly, use 'this' as the dynamic receiver.
140	 */
141	public ATObject base_sendTo(ATObject receiver, ATObject sender) throws InterpreterException {
142		return this.prim_sendTo(this, receiver, sender);
143	}
144
145	public ATMessage asMessage() {
146		return this;
147	}
148	
149}