/interpreter/tags/reactive-pattern-matching/src/edu/vub/at/exceptions/XAmbienttalk.java

 1/**
 2 * AmbientTalk/2 Project
 3 * XUserDefined.java created on Oct 10, 2006 at 9:31:40 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.objects.ATObject;
31import edu.vub.at.objects.ATTypeTag;
32import edu.vub.at.objects.coercion.NativeTypeTags;
33import edu.vub.at.objects.grammar.ATSymbol;
34import edu.vub.at.objects.natives.NATTable;
35import edu.vub.at.objects.natives.NATText;
36import edu.vub.at.objects.natives.grammar.AGAssignmentSymbol;
37import edu.vub.at.objects.natives.grammar.AGSymbol;
38
39import java.io.PrintWriter;
40import java.io.StringWriter;
41
42/**
43 * The XAmbienttalk exception class is used to wrap non-primitive exceptions in the interpreter.
44 * These exceptions are objects tagged with the Exception type which should contain a message
45 * field, which this class will read out, as well as an assignable field stackTrace which this
46 * class will initialise with the correct ambienttalk stack trace.
47 *
48 * @author smostinc
49 */
50public class XAmbienttalk extends InterpreterException {
51
52	private static final ATSymbol _STACKTRACE_SYM_ = AGAssignmentSymbol.jAlloc("stackTrace:=");
53	private static final ATSymbol _MESSAGE_SYM_ = AGSymbol.jAlloc("message");
54	
55	private static final long serialVersionUID = -2859841280138142649L;
56
57	private final ATObject customException_;
58	
59	/**
60	 * Creates a native exception wrapper given an ambienttalk exception object. This constructor
61	 * is called whenever an AmbientTalk object is being raised as this mechanism relies on the
62	 * Java level to throw an actual Java exception.
63	 * 
64	 * @param customException the object to be raised
65	 * @throws InterpreterException if the stackTrace field of the object cannot be assigned
66	 */
67	public XAmbienttalk(ATObject customException) throws InterpreterException {
68		customException_ = customException;
69		
70		StringWriter buffer = new StringWriter();
71		
72		runtimeStack_.printStackTrace(new PrintWriter(buffer, /* autoflush = */ true));
73		customException_.impl_invoke(customException_, _STACKTRACE_SYM_, NATTable.atValue(new ATObject[] { NATText.atValue(buffer.toString()) } ));
74	}
75
76	public ATObject getAmbientTalkRepresentation() {
77		return customException_;
78	}
79	
80	public ATTypeTag getType() {
81		return NativeTypeTags._CUSTOMEXCEPTION_;
82	}
83	
84	public String getMessage() {
85		try {
86			return customException_.impl_invokeAccessor(customException_, _MESSAGE_SYM_,NATTable.EMPTY).asNativeText().javaValue;
87		} catch (InterpreterException e) {
88			return "Custom exception (cannot print: "+e.getMessage()+")";
89		}
90	}
91}