/interpreter/tags/reactive-pattern-matching/src/edu/vub/at/objects/natives/NATMethod.java
Java | 188 lines | 95 code | 25 blank | 68 comment | 4 complexity | e5463bc1b682f5e842fc3e43c6f96d8c MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * NATMethod.java created on Jul 24, 2006 at 11:30:35 PM 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.PartialBinder; 31import edu.vub.at.exceptions.InterpreterException; 32import edu.vub.at.exceptions.XTypeMismatch; 33import edu.vub.at.objects.ATClosure; 34import edu.vub.at.objects.ATContext; 35import edu.vub.at.objects.ATMethod; 36import edu.vub.at.objects.ATObject; 37import edu.vub.at.objects.ATTable; 38import edu.vub.at.objects.coercion.NativeTypeTags; 39import edu.vub.at.objects.grammar.ATBegin; 40import edu.vub.at.objects.grammar.ATSymbol; 41import edu.vub.at.objects.mirrors.PrimitiveMethod; 42import edu.vub.at.signals.natives.NATLiftedBehavior; 43import edu.vub.at.util.logging.Logging; 44 45/** 46 * NATMethod implements methods as named functions which are in fact simply containers 47 * for a name, a table of arguments and a body. 48 * 49 * @author smostinc 50 * @author tvcutsem 51 */ 52public class NATMethod extends NATByCopy implements ATMethod { 53 54 private final ATSymbol name_; 55 private final ATTable parameters_; 56 private final ATBegin body_; 57 private final ATTable annotations_; 58 59 // partial function denoting a parameter binding algorithm specialized for this method's parameter list 60 private final PartialBinder parameterBindingFunction_; 61 62 /** construct a new method. This method may raise an exception if the parameter list is illegal. */ 63 public NATMethod(ATSymbol name, ATTable parameters, ATBegin body, ATTable annotations) throws InterpreterException { 64 name_ = name; 65 parameters_ = parameters; 66 body_ = body; 67 annotations_= annotations; 68 69 // calculate the parameter binding strategy to use using partial evaluation 70 parameterBindingFunction_ = 71 PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters); 72 } 73 74 /** 75 * Constructor to be used by primitive methods only. 76 */ 77 protected NATMethod(ATSymbol name, ATTable parameters, PrimitiveMethod.PrimitiveBody body, ATTable annotations) { 78 name_ = name; 79 parameters_ = parameters; 80 body_ = body; 81 annotations_= annotations; 82 83 PartialBinder parameterBindingFunction; 84 try { 85 // calculate the parameter binding strategy to use using partial evaluation 86 parameterBindingFunction = PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters); 87 } catch (InterpreterException e) { 88 parameterBindingFunction = null; 89 // this indicates a bug, primitive methods should not contain erroneous parameter lists 90 Logging.VirtualMachine_LOG.fatal("error creating primitive method: ",e); 91 } 92 parameterBindingFunction_ = parameterBindingFunction; 93 } 94 95 public ATClosure base_wrap(ATObject lexicalScope, ATObject dynamicReceiver) throws InterpreterException { 96 return new NATClosure(this, lexicalScope, dynamicReceiver); 97 } 98 99 public ATSymbol base_name() { 100 return name_; 101 } 102 103 public ATTable base_parameters() { 104 return parameters_; 105 } 106 107 public ATBegin base_bodyExpression() { 108 return body_; 109 } 110 111 public ATTable base_annotations() throws InterpreterException { 112 return annotations_; 113 } 114 115 /** 116 * To apply a function, first bind its parameters to the evaluated arguments within a new call frame. 117 * This call frame is lexically nested within the current lexical scope. 118 * 119 * This method is invoked via the following paths: 120 * - either by directly 'calling a function', in which case this method is applied via NATClosure.base_apply. 121 * The closure ensures that the context used is the lexical scope, not the dynamic scope of invocation. 122 * - or by 'invoking a method' through an object, in which case this method is applied via NATObject.meta_invoke. 123 * The enclosing object ensures that the context is properly initialized with the implementor, the dynamic receiver 124 * and the implementor's parent. 125 * 126 * @param arguments the evaluated actual arguments 127 * @param ctx the context in which to evaluate the method body, where a call frame will be inserted first 128 * @return the value of evaluating the function body 129 */ 130 public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException { 131 if(! base_annotations().base_contains(NativeTypeTags._LIFTED_).asNativeBoolean().javaValue) { 132 boolean shouldBeLifted = false; 133 ATObject[] argumentsArray = arguments.asNativeTable().elements_; 134 135 for (int argIndex = 0; argIndex < argumentsArray.length; argIndex++) { 136 ATObject currentArgument = argumentsArray[argIndex]; 137 138 if (currentArgument.isBehavior()) { 139 shouldBeLifted = true; 140 141 break; 142 } 143 } 144 145 if(shouldBeLifted) { 146 return NATLiftedBehavior.fromClosure(new NATClosure(this, ctx), argumentsArray); 147 } // else 148 } 149 150 NATCallframe cf = new NATCallframe(ctx.base_lexicalScope()); 151 ATContext evalCtx = ctx.base_withLexicalEnvironment(cf); 152 PartialBinder.defineParamsForArgs(parameterBindingFunction_, evalCtx, arguments); 153 return body_.meta_eval(evalCtx); 154 } 155 156 /** 157 * Applies the method in the context given, without first inserting a call frame to bind parameters. 158 * Arguments are bound directly in the given lexical scope. 159 * 160 * This method is often invoked via its enclosing closure when used to implement various language 161 * constructs such as object:, mirror:, extend:with: etc. 162 * 163 * @param arguments the evaluated actual arguments 164 * @param ctx the context in which to evaluate the method body, to be used as-is 165 * @return the value of evaluating the function body 166 */ 167 public ATObject base_applyInScope(ATTable arguments, ATContext ctx) throws InterpreterException { 168 PartialBinder.defineParamsForArgs(parameterBindingFunction_, ctx, arguments); 169 return body_.meta_eval(ctx); 170 } 171 172 public NATText meta_print() throws InterpreterException { 173 return NATText.atValue("<method:"+name_.meta_print().javaValue+">"); 174 } 175 176 public ATObject meta_clone() throws InterpreterException { 177 return this; 178 } 179 180 public ATMethod asMethod() throws XTypeMismatch { 181 return this; 182 } 183 184 public ATTable meta_typeTags() throws InterpreterException { 185 return NATTable.of(NativeTypeTags._METHOD_, NativeTypeTags._ISOLATE_); 186 } 187 188}