/interpreter/tags/at2dist091109/src/edu/vub/at/exceptions/XTypeMismatch.java
Java | 102 lines | 28 code | 10 blank | 64 comment | 0 complexity | e8183efe26b7abf606f29e62711211bb MD5 | raw file
1/** 2 * AmbientTalk/2 Project 3 * XTypeMismatch.java created on Jul 13, 2006 at 9:43:54 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.exceptions; 29 30import edu.vub.at.eval.Evaluator; 31import edu.vub.at.objects.ATObject; 32import edu.vub.at.objects.ATTypeTag; 33import edu.vub.at.objects.coercion.NativeTypeTags; 34 35/** 36 * XTypeMismatch instances are thrown when a value conversion failed. Value conversions occur 37 * when the interpreter expects arguments of a particular interface type (e.g. an ATClosure to 38 * apply) and the passed argument has another type. The following cases can be distinguished: 39 * <ul> 40 * <li> The argument is of a different native ambienttalk type and therefore cannot be used. 41 * In this case, an XTypeMismatch exception will be thrown.</li> 42 * <li> The argument is an ambienttalk object. At this point, the coercer will attempt to 43 * coerce the object into the correct type, which is possible only if the object has the 44 * correct native type. Otherwise, an XTypeMismatch exception will be thrown.</li> 45 * <li>The target type is a Java interface. The conversion automatically succeeds if the passed 46 * argument is a JavaObject wrapper for an object which implements the interface. If the passed 47 * argument is an ambienttalk object, the coercer will be able to dynamically synthetise a 48 * proxy implementing the interface. If the argument is of a native ambienttalk type however, 49 * an XTypeMismatch exception will be thrown.</li> 50 * <li>The target type is a Java class. If the passed argument is not a JavaObject wrapper for 51 * an instance of this class (or one of its subclasses), an XTypeMismatch exception will be 52 * thrown.</li> 53 * </ul> 54 * 55 * @author smostinc 56 * @author tvcutsem 57 */ 58public class XTypeMismatch extends InterpreterException { 59 60 private static final long serialVersionUID = -3135452124227872807L; 61 62 private final ATObject failedObject_; 63 private final Class expectedType_; 64 65 /** 66 * Creates a new type mismatch exception given the expected type and the object that could not be coerced to this type. 67 * @param expectedType a Java Class denoting the type the object was being coerced into. 68 * @param failedObject the ambienttalk value that could not be coerced into the correct type 69 */ 70 public XTypeMismatch(Class expectedType, ATObject failedObject) { 71 expectedType_ = expectedType; 72 failedObject_ = failedObject; 73 } 74 75 /** 76 * @return the ambienttalk value that could not be coerced into the correct type. 77 */ 78 public ATObject getFailedObject() { 79 return failedObject_; 80 } 81 82 /** 83 * @return a Java Class denoting the type the object was being coerced into. 84 */ 85 public Class getExpectedType() { 86 return expectedType_; 87 } 88 89 /** 90 * @return a textual description of the type mismatch exception. 91 */ 92 public String getMessage() { 93 String obj = Evaluator.toString(failedObject_); 94 return "Type mismatch: expected " + Evaluator.valueNameOf(expectedType_) 95 + ", given " + obj + " (type: " + Evaluator.valueNameOf(failedObject_.getClass())+ ")"; 96 } 97 98 public ATTypeTag getType() { 99 return NativeTypeTags._TYPEMISMATCH_; 100 } 101 102}