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
|
/*
* 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;
using System.Collections.Generic;
namespace OpenSim.Region.ScriptEngine.DotNetEngine.Compiler.YieldProlog
{
public class Functor2 : IUnifiable
{
public readonly Atom _name;
public readonly object _arg1;
public readonly object _arg2;
public Functor2(Atom name, object arg1, object arg2)
{
_name = name;
_arg1 = arg1;
_arg2 = arg2;
}
public Functor2(string name, object arg1, object arg2)
: this(Atom.a(name), arg1, arg2)
{
}
public IEnumerable<bool> unify(object arg)
{
arg = YP.getValue(arg);
if (arg is Functor2)
{
Functor2 argFunctor = (Functor2)arg;
if (_name.Equals(argFunctor._name))
{
foreach (bool l1 in YP.unify(_arg1, argFunctor._arg1))
{
foreach (bool l2 in YP.unify(_arg2, argFunctor._arg2))
yield return false;
}
}
}
else if (arg is Variable)
{
foreach (bool l1 in ((Variable)arg).unify(this))
yield return false;
}
}
public override string ToString()
{
if (_name == Atom.DOT)
return listPairToString(this);
else
return _name + "(" + YP.getValue(_arg1) + ", " + YP.getValue(_arg2) + ")";
}
public bool termEqual(object term)
{
term = YP.getValue(term);
if (term is Functor2)
{
Functor2 termFunctor = (Functor2)term;
return _name.Equals(termFunctor._name) && YP.termEqual(_arg1, termFunctor._arg1)
&& YP.termEqual(_arg2, termFunctor._arg2);
}
return false;
}
public bool lessThan(Functor2 functor)
{
// Do the equal check first since it is faster.
if (!_name.Equals(functor._name))
return _name.lessThan(functor._name);
if (!YP.termEqual(_arg1, functor._arg1))
return YP.termLessThan(_arg1, functor._arg1);
return YP.termLessThan(_arg2, functor._arg2);
}
public bool ground()
{
return YP.ground(_arg1) && YP.ground(_arg2);
}
public void addUniqueVariables(List<Variable> variableSet)
{
YP.addUniqueVariables(_arg1, variableSet);
YP.addUniqueVariables(_arg2, variableSet);
}
public object makeCopy(Variable.CopyStore copyStore)
{
return new Functor2(_name, YP.makeCopy(_arg1, copyStore),
YP.makeCopy(_arg2, copyStore));
}
private static string listPairToString(Functor2 listPair)
{
string result = "[";
while (true)
{
object head = YP.getValue(listPair._arg1);
object tail = YP.getValue(listPair._arg2);
if (tail == (object)Atom.NIL)
{
result += head;
break;
}
else if (tail is Functor2 && ((Functor2)tail)._name == Atom.DOT)
{
result += head + ", ";
listPair = (Functor2)tail;
// Loop again.
}
else
{
// The list is not terminated with NIL.
result += head + "|" + tail;
break;
}
}
result += "]";
return result;
}
}
}
|
