opensim – Blame information for rev 1
?pathlinks?
Rev | Author | Line No. | Line |
---|---|---|---|
1 | eva | 1 | /* |
2 | * Copyright (C) 2007-2008, Jeff Thompson |
||
3 | * |
||
4 | * All rights reserved. |
||
5 | * |
||
6 | * Redistribution and use in source and binary forms, with or without |
||
7 | * modification, are permitted provided that the following conditions are met: |
||
8 | * |
||
9 | * * Redistributions of source code must retain the above copyright |
||
10 | * notice, this list of conditions and the following disclaimer. |
||
11 | * * Redistributions in binary form must reproduce the above copyright |
||
12 | * notice, this list of conditions and the following disclaimer in the |
||
13 | * documentation and/or other materials provided with the distribution. |
||
14 | * * Neither the name of the copyright holder nor the names of its contributors |
||
15 | * may be used to endorse or promote products derived from this software |
||
16 | * without specific prior written permission. |
||
17 | * |
||
18 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
||
19 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
||
20 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
||
21 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR |
||
22 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
||
23 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
||
24 | * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
||
25 | * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
||
26 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
||
27 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
||
28 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||
29 | */ |
||
30 | |||
31 | using System; |
||
32 | using System.Collections.Generic; |
||
33 | using System.Text; |
||
34 | |||
35 | namespace OpenSim.Region.ScriptEngine.Shared.YieldProlog |
||
36 | { |
||
37 | public class Atom : IUnifiable |
||
38 | { |
||
39 | private static Dictionary<string, Atom> _atomStore = new Dictionary<string, Atom>(); |
||
40 | public readonly string _name; |
||
41 | public readonly Atom _module; |
||
42 | |||
43 | /// <summary> |
||
44 | /// You should not call this constructor, but use Atom.a instead. |
||
45 | /// </summary> |
||
46 | /// <param name="name"></param> |
||
47 | /// <param name="module"></param> |
||
48 | private Atom(string name, Atom module) |
||
49 | { |
||
50 | _name = name; |
||
51 | _module = module; |
||
52 | } |
||
53 | |||
54 | /// <summary> |
||
55 | /// Return the unique Atom object for name where module is null. You should use this to create |
||
56 | /// an Atom instead of calling the Atom constructor. |
||
57 | /// </summary> |
||
58 | /// <param name="name"></param> |
||
59 | /// <returns></returns> |
||
60 | public static Atom a(string name) |
||
61 | { |
||
62 | Atom atom; |
||
63 | if (!_atomStore.TryGetValue(name, out atom)) |
||
64 | { |
||
65 | atom = new Atom(name, null); |
||
66 | _atomStore[name] = atom; |
||
67 | } |
||
68 | return atom; |
||
69 | } |
||
70 | |||
71 | /// <summary> |
||
72 | /// Return an Atom object with the name and module. If module is null or Atom.NIL, |
||
73 | /// this behaves like Atom.a(name) and returns the unique object where the module is null. |
||
74 | /// If module is not null or Atom.NIL, this may or may not be the same object as another Atom |
||
75 | /// with the same name and module. |
||
76 | /// </summary> |
||
77 | /// <param name="name"></param> |
||
78 | /// <param name="module"></param> |
||
79 | /// <returns></returns> |
||
80 | public static Atom a(string name, Atom module) |
||
81 | { |
||
82 | if (module == null || module == Atom.NIL) |
||
83 | return a(name); |
||
84 | return new Atom(name, module); |
||
85 | } |
||
86 | |||
87 | /// <summary> |
||
88 | /// If Obj is an Atom unify its _module with Module. If the Atom's _module is null, use Atom.NIL. |
||
89 | /// </summary> |
||
90 | /// <param name="Atom"></param> |
||
91 | /// <param name="Module"></param> |
||
92 | /// <returns></returns> |
||
93 | public static IEnumerable<bool> module(object Obj, object Module) |
||
94 | { |
||
95 | Obj = YP.getValue(Obj); |
||
96 | if (Obj is Atom) |
||
97 | { |
||
98 | if (((Atom)Obj)._module == null) |
||
99 | return YP.unify(Module, Atom.NIL); |
||
100 | else |
||
101 | return YP.unify(Module, ((Atom)Obj)._module); |
||
102 | } |
||
103 | return YP.fail(); |
||
104 | } |
||
105 | |||
106 | public static readonly Atom NIL = Atom.a("[]"); |
||
107 | public static readonly Atom DOT = Atom.a("."); |
||
108 | public static readonly Atom F = Atom.a("f"); |
||
109 | public static readonly Atom SLASH = Atom.a("/"); |
||
110 | public static readonly Atom HAT = Atom.a("^"); |
||
111 | public static readonly Atom RULE = Atom.a(":-"); |
||
112 | |||
113 | public IEnumerable<bool> unify(object arg) |
||
114 | { |
||
115 | arg = YP.getValue(arg); |
||
116 | if (arg is Atom) |
||
117 | return Equals(arg) ? YP.succeed() : YP.fail(); |
||
118 | else if (arg is Variable) |
||
119 | return ((Variable)arg).unify(this); |
||
120 | else |
||
121 | return YP.fail(); |
||
122 | } |
||
123 | |||
124 | public void addUniqueVariables(List<Variable> variableSet) |
||
125 | { |
||
126 | // Atom does not contain variables. |
||
127 | } |
||
128 | |||
129 | public object makeCopy(Variable.CopyStore copyStore) |
||
130 | { |
||
131 | // Atom does not contain variables that need to be copied. |
||
132 | return this; |
||
133 | } |
||
134 | |||
135 | public bool termEqual(object term) |
||
136 | { |
||
137 | return Equals(YP.getValue(term)); |
||
138 | } |
||
139 | |||
140 | public bool ground() |
||
141 | { |
||
142 | // Atom is always ground. |
||
143 | return true; |
||
144 | } |
||
145 | |||
146 | public override bool Equals(object obj) |
||
147 | { |
||
148 | if (obj is Atom) |
||
149 | { |
||
150 | if (_module == null && ((Atom)obj)._module == null) |
||
151 | // When _declaringClass is null, we always use an identical object from _atomStore. |
||
152 | return this == obj; |
||
153 | // Otherwise, ignore _declaringClass and do a normal string compare on the _name. |
||
154 | return _name == ((Atom)obj)._name; |
||
155 | } |
||
156 | return false; |
||
157 | } |
||
158 | |||
159 | public override string ToString() |
||
160 | { |
||
161 | return _name; |
||
162 | } |
||
163 | |||
164 | public override int GetHashCode() |
||
165 | { |
||
166 | // Debug: need to check _declaringClass. |
||
167 | return _name.GetHashCode(); |
||
168 | } |
||
169 | |||
170 | public string toQuotedString() |
||
171 | { |
||
172 | if (_name.Length == 0) |
||
173 | return "''"; |
||
174 | else if (this == Atom.NIL) |
||
175 | return "[]"; |
||
176 | |||
177 | StringBuilder result = new StringBuilder(_name.Length); |
||
178 | bool useQuotes = false; |
||
179 | foreach (char c in _name) |
||
180 | { |
||
181 | int cInt = (int)c; |
||
182 | if (c == '\'') |
||
183 | { |
||
184 | result.Append("''"); |
||
185 | useQuotes = true; |
||
186 | } |
||
187 | else if (c == '_' || cInt >= (int)'a' && cInt <= (int)'z' || |
||
188 | cInt >= (int)'A' && cInt <= (int)'Z' || cInt >= (int)'0' && cInt <= (int)'9') |
||
189 | result.Append(c); |
||
190 | else |
||
191 | { |
||
192 | // Debug: Need to handle non-printable chars. |
||
193 | result.Append(c); |
||
194 | useQuotes = true; |
||
195 | } |
||
196 | } |
||
197 | |||
198 | if (!useQuotes && (int)_name[0] >= (int)'a' && (int)_name[0] <= (int)'z') |
||
199 | return result.ToString(); |
||
200 | else |
||
201 | { |
||
202 | // Surround in single quotes. |
||
203 | result.Append('\''); |
||
204 | return "'" + result; |
||
205 | } |
||
206 | } |
||
207 | |||
208 | /// <summary> |
||
209 | /// Return true if _name is lexicographically less than atom._name. |
||
210 | /// </summary> |
||
211 | /// <param name="atom"></param> |
||
212 | /// <returns></returns> |
||
213 | public bool lessThan(Atom atom) |
||
214 | { |
||
215 | return _name.CompareTo(atom._name) < 0; |
||
216 | } |
||
217 | } |
||
218 | } |