/interpreter/tags/at2dist091109/src/edu/vub/at/objects/natives/grammar/AGAssignField.java
Java | 118 lines | 54 code | 14 blank | 50 comment | 0 complexity | f99d7ff8efd3dc60efbd933fe01f22b9 MD5 | raw file
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.eval.InvocationStack; 31import edu.vub.at.exceptions.InterpreterException; 32import edu.vub.at.objects.ATContext; 33import edu.vub.at.objects.ATObject; 34import edu.vub.at.objects.grammar.ATAssignField; 35import edu.vub.at.objects.grammar.ATExpression; 36import edu.vub.at.objects.grammar.ATSymbol; 37import edu.vub.at.objects.natives.NATTable; 38import edu.vub.at.objects.natives.NATText; 39 40import java.util.Set; 41 42/** 43 * The native implementation of a field assignment AG element. 44 * 45 * @author tvc 46 */ 47public final class AGAssignField extends NATAbstractGrammar implements ATAssignField { 48 49 private final ATExpression rcvExp_; 50 private final ATSymbol fieldName_; 51 private final ATExpression valueExp_; 52 53 public AGAssignField(ATExpression rcv, ATSymbol nam, ATExpression val) { 54 rcvExp_ = rcv; 55 fieldName_ = nam; 56 valueExp_ = val; 57 } 58 59 public ATExpression base_receiverExpression() { return rcvExp_; } 60 61 public ATSymbol base_fieldName() { return fieldName_; } 62 63 public ATExpression base_valueExpression() { return valueExp_; } 64 65 /** 66 * To evaluate a field assignment, evaluate the receiver expression, evaluate the right hand side and ask 67 * the receiver object to assign the RHS value to the field corresponding to the given field name. 68 * 69 * In AmbientTalk using the uniform access principle, assignments are represented as message sends. 70 * For example <tt>o.x := 5</tt> is represented as <tt>o.x:=(5)</tt> where <tt>`x:=</tt> is a special 71 * selector identifying a field assignment. 72 * 73 * AGASSFIELD(rcv,nam,val).eval(ctx) = rcv.eval(ctx).invoke(rcv,nam:=, [ val.eval(ctx) ]) 74 * 75 * @return the new value of the field 76 */ 77 public ATObject meta_eval(ATContext ctx) throws InterpreterException { 78 ATObject receiver = rcvExp_.meta_eval(ctx); 79 NATTable arg = NATTable.of(valueExp_.meta_eval(ctx)); 80 ATObject result = null; 81 InvocationStack stack = InvocationStack.getInvocationStack(); 82 try { 83 stack.methodInvoked(this, receiver, arg); 84 result = receiver.impl_invokeMutator(receiver, fieldName_.asAssignmentSymbol(), arg); 85 } finally { 86 stack.methodReturned(result); 87 } 88 return result; 89 } 90 91 /** 92 * AGASSFIELD(rcv,nam,val).quote(ctx) = AGASSFIELD(rcv.quote(ctx), nam.quote(ctx), val.quote(ctx)) 93 */ 94 public ATObject meta_quote(ATContext ctx) throws InterpreterException { 95 return new AGAssignField(rcvExp_.meta_quote(ctx).asExpression(), fieldName_.meta_quote(ctx).asSymbol(), valueExp_.meta_quote(ctx).asExpression()); 96 } 97 98 public NATText meta_print() throws InterpreterException { 99 return NATText.atValue(rcvExp_.meta_print().javaValue + "." + fieldName_.meta_print().javaValue + " := " + valueExp_.meta_print().javaValue); 100 } 101 102 /** 103 * FV(rcvexp.x := exp) = FV(rcvexp) U FV(exp) 104 */ 105 public Set impl_freeVariables() throws InterpreterException { 106 Set fvRcvExp = rcvExp_.impl_freeVariables(); 107 fvRcvExp.addAll(valueExp_.impl_freeVariables()); 108 return fvRcvExp; 109 } 110 111 public Set impl_quotedFreeVariables() throws InterpreterException { 112 Set fvRcvExp = rcvExp_.impl_quotedFreeVariables(); 113 fvRcvExp.addAll(fieldName_.impl_quotedFreeVariables()); 114 fvRcvExp.addAll(valueExp_.impl_quotedFreeVariables()); 115 return fvRcvExp; 116 } 117 118}