/interpreter/tags/at2dist220411/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.Set;
 48import java.util.Vector;
 49
 50/**
 51 * Instances of this class represent first-class messages.
 52 * This is an abstract class, as it can be either a synchronous method invocation or an asynchronous message send.
 53 * 
 54 * This class is a subclass of {@link NATObject}, such that its instances represent true AmbientTalk objects.
 55 * 
 56 * @author tvcutsem
 57 */
 58public abstract class NATMessage extends NATObject implements ATMessage {
 59	
 60	private final static AGSymbol _SELECTOR_ = AGSymbol.jAlloc("selector");
 61	private final static AGSymbol _ARGUMENTS_ = AGSymbol.jAlloc("arguments");
 62	
 63	/** def sendTo(receiver, sender) { nil } */
 64	private static final PrimitiveMethod _PRIM_SND_ = new PrimitiveMethod(        
 65			AGSymbol.jAlloc("sendTo"), NATTable.atValue(new ATObject[] { AGSymbol.jAlloc("receiver"), AGSymbol.jAlloc("sender") })) {
 66      private static final long serialVersionUID = -3475956316807558583L;
 67
 68      public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
 69			int arity = arguments.base_length().asNativeNumber().javaValue;
 70			if (arity != 2) {
 71				throw new XArityMismatch("sendTo", 2, arity);
 72			}
 73			return ctx.base_lexicalScope().asMessage().prim_sendTo(
 74					ctx.base_receiver().asMessage(),
 75					arguments.base_at(NATNumber.ONE), arguments.base_at(NATNumber.atValue(2)));
 76		}
 77	};
 78	
 79	/** def from(sender) { nil } */
 80	private static final PrimitiveMethod _PRIM_FRM_ = new PrimitiveMethod(        
 81			AGSymbol.jAlloc("from"), NATTable.atValue(new ATObject[] { AGSymbol.jAlloc("sender") })) {
 82	  private static final long serialVersionUID = -5721508425469755751L;
 83		
 84      public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
 85			int arity = arguments.base_length().asNativeNumber().javaValue;
 86			if (arity != 1) {
 87				throw new XArityMismatch("from", 1, arity);
 88			}
 89			return ctx.base_lexicalScope().asMessage().base_from(arguments.base_at(NATNumber.ONE));
 90	  }
 91	};
 92	
 93	
 94    /**
 95     * Converts the given table of annotations into an ATTypeTag array.
 96     * Each element of the annotations table is converted into a type.
 97     * Moreover, because messages are isolates, the Isolate type is automatically appended to the resulting array.
 98     * Also, each type of message has its own type of type, so a subtype of Message is also added.
 99     */
100    protected static ATTypeTag[] annotationsToTypes(ATTypeTag msgType, ATTable annotations) throws InterpreterException {
101		if (annotations == NATTable.EMPTY) {
102			return new ATTypeTag[] { NativeTypeTags._ISOLATE_, msgType };
103		}
104    	
105        ATObject[] unwrapped = annotations.asNativeTable().elements_;
106		ATTypeTag[] fulltypes = new ATTypeTag[unwrapped.length+2];
107		for (int i = 0; i < unwrapped.length; i++) {
108			fulltypes[i] = unwrapped[i].asTypeTag();
109		}
110		fulltypes[unwrapped.length] = NativeTypeTags._ISOLATE_;
111		fulltypes[unwrapped.length+1] = msgType;
112        return fulltypes;
113    }
114	
115	/**
116	 * Construct a new message from the given selector, arguments and annotations.
117	 * The annotations become this message's types.
118	 * 
119	 * @param annotations a table of objects that should be convertible to types
120	 * @param msgType a subtype of the Message type, added by subclasses to mark which kind of native message is created
121	 */
122	protected NATMessage(ATSymbol sel, ATTable arg, ATTable annotations, ATTypeTag msgType) throws InterpreterException {
123		super(annotationsToTypes(msgType, annotations));
124		super.meta_defineField(_SELECTOR_, sel);
125		super.meta_defineField(_ARGUMENTS_, arg);
126		super.meta_addMethod(_PRIM_SND_);
127		super.meta_addMethod(_PRIM_FRM_);
128	}
129
130    /**
131     * Copy constructor.
132     */
133    protected NATMessage(FieldMap map,
134            Vector state,
135            LinkedList originalCustomFields,
136            MethodDictionary methodDict,
137            ATObject dynamicParent,
138            ATObject lexicalParent,
139            byte flags,
140            ATTypeTag[] types,
141            Set freeVars) throws InterpreterException {
142    	super(map, state, originalCustomFields, methodDict, dynamicParent, lexicalParent, flags, types, freeVars);
143    }
144	
145	public ATSymbol base_selector() throws InterpreterException {
146		return super.meta_invokeField(this, _SELECTOR_).asSymbol();
147	}
148
149	public ATTable base_arguments() throws InterpreterException {
150		return super.meta_invokeField(this, _ARGUMENTS_).asTable();
151	}
152	
153	public ATNil base_arguments__opeql_(ATTable arguments) throws InterpreterException {
154		super.impl_invokeMutator(this, _ARGUMENTS_.asAssignmentSymbol(), NATTable.of(arguments));
155		return Evaluator.getNil();
156	}
157	
158	public ATClosure base_from(final ATObject sender) {
159		final NATMessage msg = this;
160		return new NativeClosure(this) {
161			private static final long serialVersionUID = -5978871207209804505L;
162			public ATObject base_apply(ATTable args) throws InterpreterException {
163				ATObject[] arguments = args.asNativeTable().elements_;
164				if (arguments.length != 1) {
165					throw new XArityMismatch(msg.toString(), 1, arguments.length);
166				}
167				return msg.base_sendTo(arguments[0], sender);
168			}
169		};
170	}
171	
172	/**
173	 * If sendTo is invoked from the Java-level directly, use 'this' as the dynamic receiver.
174	 */
175	public ATObject base_sendTo(ATObject receiver, ATObject sender) throws InterpreterException {
176		return this.prim_sendTo(this, receiver, sender);
177	}
178
179	public ATMessage asMessage() {
180		return this;
181	}
182	
183}