/interpreter/tags/at2dist091109/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.eval.Evaluator;
 31import edu.vub.at.exceptions.InterpreterException;
 32import edu.vub.at.exceptions.XArityMismatch;
 33import edu.vub.at.objects.ATClosure;
 34import edu.vub.at.objects.ATContext;
 35import edu.vub.at.objects.ATMessage;
 36import edu.vub.at.objects.ATNil;
 37import edu.vub.at.objects.ATObject;
 38import edu.vub.at.objects.ATTable;
 39import edu.vub.at.objects.ATTypeTag;
 40import edu.vub.at.objects.coercion.NativeTypeTags;
 41import edu.vub.at.objects.grammar.ATSymbol;
 42import edu.vub.at.objects.mirrors.NativeClosure;
 43import edu.vub.at.objects.mirrors.PrimitiveMethod;
 44import edu.vub.at.objects.natives.grammar.AGSymbol;
 45
 46import java.util.LinkedList;
 47import java.util.Vector;
 48
 49/**
 50 * Instances of this class represent first-class messages.
 51 * This is an abstract class, as it can be either a synchronous method invocation or an asynchronous message send.
 52 * 
 53 * This class is a subclass of {@link NATObject}, such that its instances represent true AmbientTalk objects.
 54 * 
 55 * @author tvcutsem
 56 */
 57public abstract class NATMessage extends NATObject implements ATMessage {
 58	
 59	private final static AGSymbol _SELECTOR_ = AGSymbol.jAlloc("selector");
 60	private final static AGSymbol _ARGUMENTS_ = AGSymbol.jAlloc("arguments");
 61	
 62	/** def sendTo(receiver, sender) { nil } */
 63	private static final PrimitiveMethod _PRIM_SND_ = new PrimitiveMethod(        
 64			AGSymbol.jAlloc("sendTo"), NATTable.atValue(new ATObject[] { AGSymbol.jAlloc("receiver"), AGSymbol.jAlloc("sender") })) {
 65      private static final long serialVersionUID = -3475956316807558583L;
 66
 67      public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
 68			int arity = arguments.base_length().asNativeNumber().javaValue;
 69			if (arity != 2) {
 70				throw new XArityMismatch("sendTo", 2, arity);
 71			}
 72			return ctx.base_lexicalScope().asMessage().prim_sendTo(
 73					ctx.base_receiver().asMessage(),
 74					arguments.base_at(NATNumber.ONE), arguments.base_at(NATNumber.atValue(2)));
 75		}
 76	};
 77	
 78	/** def from(sender) { nil } */
 79	private static final PrimitiveMethod _PRIM_FRM_ = new PrimitiveMethod(        
 80			AGSymbol.jAlloc("from"), NATTable.atValue(new ATObject[] { AGSymbol.jAlloc("sender") })) {
 81	  private static final long serialVersionUID = -5721508425469755751L;
 82		
 83      public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
 84			int arity = arguments.base_length().asNativeNumber().javaValue;
 85			if (arity != 1) {
 86				throw new XArityMismatch("from", 1, arity);
 87			}
 88			return ctx.base_lexicalScope().asMessage().base_from(arguments.base_at(NATNumber.ONE));
 89	  }
 90	};
 91	
 92	
 93    /**
 94     * Converts the given table of annotations into an ATTypeTag array.
 95     * Each element of the annotations table is converted into a type.
 96     * Moreover, because messages are isolates, the Isolate type is automatically appended to the resulting array.
 97     * Also, each type of message has its own type of type, so a subtype of Message is also added.
 98     */
 99    protected static ATTypeTag[] annotationsToTypes(ATTypeTag msgType, ATTable annotations) throws InterpreterException {
100		if (annotations == NATTable.EMPTY) {
101			return new ATTypeTag[] { NativeTypeTags._ISOLATE_, msgType };
102		}
103    	
104        ATObject[] unwrapped = annotations.asNativeTable().elements_;
105		ATTypeTag[] fulltypes = new ATTypeTag[unwrapped.length+2];
106		for (int i = 0; i < unwrapped.length; i++) {
107			fulltypes[i] = unwrapped[i].asTypeTag();
108		}
109		fulltypes[unwrapped.length] = NativeTypeTags._ISOLATE_;
110		fulltypes[unwrapped.length+1] = msgType;
111        return fulltypes;
112    }
113	
114	/**
115	 * Construct a new message from the given selector, arguments and annotations.
116	 * The annotations become this message's types.
117	 * 
118	 * @param annotations a table of objects that should be convertible to types
119	 * @param msgType a subtype of the Message type, added by subclasses to mark which kind of native message is created
120	 */
121	protected NATMessage(ATSymbol sel, ATTable arg, ATTable annotations, ATTypeTag msgType) throws InterpreterException {
122		super(annotationsToTypes(msgType, annotations));
123		super.meta_defineField(_SELECTOR_, sel);
124		super.meta_defineField(_ARGUMENTS_, arg);
125		super.meta_addMethod(_PRIM_SND_);
126		super.meta_addMethod(_PRIM_FRM_);
127	}
128
129    /**
130     * Copy constructor.
131     */
132    protected NATMessage(FieldMap map,
133            Vector state,
134            LinkedList originalCustomFields,
135            MethodDictionary methodDict,
136            ATObject dynamicParent,
137            ATObject lexicalParent,
138            byte flags,
139            ATTypeTag[] types) throws InterpreterException {
140    	super(map, state, originalCustomFields, methodDict, dynamicParent, lexicalParent, flags, types);
141    }
142	
143	public ATSymbol base_selector() throws InterpreterException {
144		return super.meta_invokeField(this, _SELECTOR_).asSymbol();
145	}
146
147	public ATTable base_arguments() throws InterpreterException {
148		return super.meta_invokeField(this, _ARGUMENTS_).asTable();
149	}
150	
151	public ATNil base_arguments__opeql_(ATTable arguments) throws InterpreterException {
152		super.impl_invokeMutator(this, _ARGUMENTS_.asAssignmentSymbol(), NATTable.of(arguments));
153		return Evaluator.getNil();
154	}
155	
156	public ATClosure base_from(final ATObject sender) {
157		final NATMessage msg = this;
158		return new NativeClosure(this) {
159			private static final long serialVersionUID = -5978871207209804505L;
160			public ATObject base_apply(ATTable args) throws InterpreterException {
161				ATObject[] arguments = args.asNativeTable().elements_;
162				if (arguments.length != 1) {
163					throw new XArityMismatch(msg.toString(), 1, arguments.length);
164				}
165				return msg.base_sendTo(arguments[0], sender);
166			}
167		};
168	}
169	
170	/**
171	 * If sendTo is invoked from the Java-level directly, use 'this' as the dynamic receiver.
172	 */
173	public ATObject base_sendTo(ATObject receiver, ATObject sender) throws InterpreterException {
174		return this.prim_sendTo(this, receiver, sender);
175	}
176
177	public ATMessage asMessage() {
178		return this;
179	}
180	
181}