aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/ScriptEngine/DotNetEngine/Compiler/YieldProlog/PrologException.cs
blob: 56ed7191a65c19f7c1bcf5e72f1da733891ba0ae (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
/*
 * Copyright (C) 2007-2008, Jeff Thompson
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the copyright holder nor the names of its contributors
 *       may be used to endorse or promote products derived from this software
 *       without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;

namespace OpenSim.Region.ScriptEngine.DotNetEngine.Compiler.YieldProlog
{
    /// <summary>
    /// A PrologException is used as the exception thrown by YP.throw(Term).
    /// </summary>
    public class PrologException : Exception
    {
        public readonly object _term;

        /// <summary>
        /// Create a PrologException with the given Term.  The printable exception message is the full Term.
        /// </summary>
        /// <param name="Term">the term of the exception</param>
        public PrologException(object Term)
            : base(YP.getValue(Term).ToString())
        {
            _term = YP.makeCopy(Term, new Variable.CopyStore());
        }

        /// <summary>
        /// Create a PrologException where the Term is error(ErrorTerm, Message).
        /// This uses YP.makeCopy to copy the ErrorTerm and Message so that they are valid after unbinding.
        /// </summary>
        /// <param name="ErrorTerm">the error term of the error</param>
        /// <param name="Messsage">the message term of the error.  If this is a string, it is converted to an
        /// Atom so it can be used by Prolog code.
        /// Message, converted to a string, is use as the printable exception message.
        /// </param>
        public PrologException(object ErrorTerm, object Message)
            : base(YP.getValue(Message).ToString())
        {
            if (Message is string)
                Message = Atom.a((string)Message);
            _term = YP.makeCopy(new Functor2(Atom.a("error"), ErrorTerm, Message), new Variable.CopyStore());
        }

        public class TypeErrorInfo
        {
            public readonly Atom _Type;
            public readonly object _Culprit;
            public readonly object _Message;

            public TypeErrorInfo(Atom Type, object Culprit, object Message)
            {
                _Type = Type;
                _Culprit = Culprit;
                _Message = Message;
            }
        }
        /// <summary>
        /// Return the TypeErrorInfo for this exception, or null if _term does not match
        ///   error(type_error(Type, Culprit), Message).
        /// </summary>
        /// <returns></returns>
        public TypeErrorInfo getTypeErrorInfo()
        {
            if (!(_term is Functor2 && ((Functor2)_term)._name._name == "error"))
                return null;
            object errorTerm = ((Functor2)_term)._arg1;
            if (!(errorTerm is Functor2 && ((Functor2)errorTerm)._name._name == "type_error"))
                return null;
            if (!(((Functor2)errorTerm)._arg1 is Atom))
                return null;
            return new TypeErrorInfo
                ((Atom)((Functor2)errorTerm)._arg1, ((Functor2)errorTerm)._arg2, ((Functor2)_term)._arg2);
        }

        public class ExistenceErrorInfo
        {
            public readonly Atom _Type;
            public readonly object _Culprit;
            public readonly object _Message;

            public ExistenceErrorInfo(Atom Type, object Culprit, object Message)
            {
                _Type = Type;
                _Culprit = Culprit;
                _Message = Message;
            }

            /// <summary>
            /// If _Type is procedure and _Culprit is name/artity, return the name.  Otherwise return null.
            /// </summary>
            /// <returns></returns>
            public object getProcedureName()
            {
                if (!(_Type._name == "procedure" &&
                      _Culprit is Functor2 && ((Functor2)_Culprit)._name == Atom.SLASH))
                    return null;
                return ((Functor2)_Culprit)._arg1;
            }

            /// <summary>
            /// If _Type is procedure and _Culprit is name/arity and arity is an integer, return the arity.
            /// Otherwise return -1.
            /// </summary>
            /// <returns></returns>
            public int getProcedureArity()
            {
                if (!(_Type._name == "procedure" &&
                      _Culprit is Functor2 && ((Functor2)_Culprit)._name == Atom.SLASH))
                    return -1;
                if (!(((Functor2)_Culprit)._arg2 is int))
                    return -1;
                return (int)((Functor2)_Culprit)._arg2;
            }
        }
        /// <summary>
        /// Return the ExistenceErrorInfo for this exception, or null if _term does not match
        ///   error(existence_error(Type, Culprit), Message).  If the returned ExistenceErrorInfo _Culprit is
        ///   procedure, you can use its getProcedureName and getProcedureArity.
        /// </summary>
        /// <returns></returns>
        public ExistenceErrorInfo getExistenceErrorInfo()
        {
            if (!(_term is Functor2 && ((Functor2)_term)._name._name == "error"))
                return null;
            object errorTerm = ((Functor2)_term)._arg1;
            if (!(errorTerm is Functor2 && ((Functor2)errorTerm)._name._name == "existence_error"))
                return null;
            if (!(((Functor2)errorTerm)._arg1 is Atom))
                return null;
            return new ExistenceErrorInfo
                ((Atom)((Functor2)errorTerm)._arg1, ((Functor2)errorTerm)._arg2, ((Functor2)_term)._arg2);
        }
    }
}