/interpreter/tags/at2dist041108/src/edu/vub/at/objects/natives/grammar/AGDefExternalMethod.java
Java | 196 lines | 110 code | 26 blank | 60 comment | 7 complexity | 953015c236434a752048389be5416439 MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * AGDefExternalMethod.java created on 15-nov-2006 at 19:33:18 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.Evaluator; 31import edu.vub.at.exceptions.InterpreterException; 32import edu.vub.at.exceptions.XIllegalOperation; 33import edu.vub.at.objects.ATContext; 34import edu.vub.at.objects.ATMethod; 35import edu.vub.at.objects.ATObject; 36import edu.vub.at.objects.ATTable; 37import edu.vub.at.objects.ATTypeTag; 38import edu.vub.at.objects.coercion.NativeTypeTags; 39import edu.vub.at.objects.grammar.ATBegin; 40import edu.vub.at.objects.grammar.ATDefExternalMethod; 41import edu.vub.at.objects.grammar.ATDefinition; 42import edu.vub.at.objects.grammar.ATExpression; 43import edu.vub.at.objects.grammar.ATSymbol; 44import edu.vub.at.objects.natives.NATClosureMethod; 45import edu.vub.at.objects.natives.NATMethod; 46import edu.vub.at.objects.natives.NATTable; 47import edu.vub.at.objects.natives.NATText; 48 49import java.util.HashSet; 50import java.util.Set; 51 52/** 53 * The native implementation of an external method definition abstract grammar element. 54 * 55 * @author tvcutsem 56 */ 57public final class AGDefExternalMethod extends AGDefinition implements ATDefExternalMethod { 58 59 private final ATSymbol rcvNam_; 60 private final ATSymbol selectorExp_; 61 private final ATTable argumentExps_; 62 private final ATBegin bodyStmts_; 63 private final ATExpression annotationExps_; 64 65 private ATMethod preprocessedMethod_; 66 67 public AGDefExternalMethod(ATSymbol rcv, ATSymbol sel, ATTable args, ATBegin bdy, ATExpression ann) 68 throws InterpreterException { 69 rcvNam_ = rcv; 70 selectorExp_ = sel; 71 argumentExps_ = args; 72 bodyStmts_ = bdy; 73 annotationExps_ = ann; 74 } 75 76 public ATSymbol base_receiver() { 77 return rcvNam_; 78 } 79 80 public ATSymbol base_selector() { 81 return selectorExp_; 82 } 83 84 public ATTable base_arguments() { 85 return argumentExps_; 86 } 87 88 public ATBegin base_bodyExpression() { 89 return bodyStmts_; 90 } 91 92 public ATExpression base_annotationExpression() { 93 return annotationExps_; 94 } 95 96 /** 97 * Evaluates the receiver symbol to an object to which a new 'closure method' will be added. 98 * Such a closure captures the current lexical scope, but not the values for 'self' and 'super'. 99 * 100 * The return value of an external method definition is always the external method itself. 101 * 102 * AGDEFEXTMTH(rcv,nam,par,bdy).eval(ctx) = 103 * rcv.eval(ctx).defineField(nam, NATCLOMTH(ctx.cur,nam,par,bdy)) 104 * 105 * @throws XIllegalOperation if the receiver is an instance of a native 106 * type (whose method dictionaries are sealed) or if the receiver is an isolate. 107 */ 108 public ATObject meta_eval(ATContext ctx) throws InterpreterException { 109 // the method is not yet created in the constructor because this gives problems 110 // with quoted parameters: a quoted parameter would result in an illegal parameter 111 // exception while actually the external method was defined in the context of a quotation, 112 // so at runtime the external definition would have never been evaluated (but quoted instead) 113 if (preprocessedMethod_ == null) { 114 ATObject oneOrMoreAnnotation = annotationExps_.meta_eval(ctx); 115 ATTable annotationTable; 116 117 if(oneOrMoreAnnotation.isTable()) { 118 annotationTable = oneOrMoreAnnotation.asTable(); 119 } else { 120 annotationTable = NATTable.of(oneOrMoreAnnotation); 121 } 122 123 preprocessedMethod_ = new NATMethod(selectorExp_, argumentExps_, bodyStmts_, annotationTable); 124 125 ATObject[] annotations = annotationTable.asNativeTable().elements_; 126 127 for (int i = 0; i < annotations.length; i++) { 128 ATTypeTag theAnnotation = annotations[i].asTypeTag(); 129 130 preprocessedMethod_ = theAnnotation.base_annotateMethod(preprocessedMethod_); 131 } 132 } 133 134 ATObject receiver = rcvNam_.meta_eval(ctx); 135 if (receiver.meta_isTaggedAs(NativeTypeTags._ISOLATE_).asNativeBoolean().javaValue) { 136 throw new XIllegalOperation("Cannot define external methods on isolates"); 137 138 } else { 139 NATClosureMethod extMethod = new NATClosureMethod(ctx.base_lexicalScope(), 140 preprocessedMethod_); 141 142 receiver.meta_addMethod(extMethod); 143 return extMethod; 144 } 145 } 146 147 /** 148 * Quoting an external method definition results in a new quoted external method definition. 149 * 150 * AGDEFEXTMTH(rcv,nam,par,bdy).quote(ctx) = AGDEFEXTMTH(rcv.quote(ctx),nam.quote(ctx), par.quote(ctx), bdy.quote(ctx)) 151 */ 152 public ATObject meta_quote(ATContext ctx) throws InterpreterException { 153 return new AGDefExternalMethod(rcvNam_.meta_quote(ctx).asSymbol(), 154 selectorExp_.meta_quote(ctx).asSymbol(), 155 argumentExps_.meta_quote(ctx).asTable(), 156 bodyStmts_.meta_quote(ctx).asBegin(), 157 annotationExps_.meta_quote(ctx).asExpression()); 158 } 159 160 public NATText meta_print() throws InterpreterException { 161 return NATText.atValue("def " + 162 rcvNam_.meta_print().javaValue + "." + 163 selectorExp_.meta_print().javaValue + 164 Evaluator.printAsList(argumentExps_).javaValue + 165 " { " + bodyStmts_.meta_print().javaValue + " }"); 166 } 167 168 /** 169 * IV(def o.m(args) @ anns { body }) = { } 170 */ 171 public Set impl_introducedVariables() throws InterpreterException { 172 return new HashSet(); 173 } 174 175 /** 176 * FV(def o.m(args) @ anns { body }) = 177 * { o } U FV(anns) U FV(optionalArgExps) U (FV(body) \ { args }) 178 */ 179 public Set impl_freeVariables() throws InterpreterException { 180 Set fvBody = bodyStmts_.impl_freeVariables(); 181 Evaluator.processFreeVariables(fvBody, argumentExps_); 182 fvBody.add(rcvNam_); 183 fvBody.addAll(annotationExps_.impl_freeVariables()); 184 return fvBody; 185 } 186 187 public Set impl_quotedFreeVariables() throws InterpreterException { 188 Set qfv = argumentExps_.impl_quotedFreeVariables(); 189 qfv.addAll(bodyStmts_.impl_quotedFreeVariables()); 190 qfv.addAll(annotationExps_.impl_quotedFreeVariables()); 191 qfv.addAll(rcvNam_.impl_quotedFreeVariables()); 192 qfv.addAll(selectorExp_.impl_quotedFreeVariables()); 193 return qfv; 194 } 195 196}