Functor3.cs 5.3 KB

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  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. using System;
  31. using System.Collections.Generic;
  32. namespace OpenSim.Region.ScriptEngine.Shared.YieldProlog
  33. {
  34. public class Functor3 : IUnifiable
  35. {
  36. public readonly Atom _name;
  37. public readonly object _arg1;
  38. public readonly object _arg2;
  39. public readonly object _arg3;
  40. public Functor3(Atom name, object arg1, object arg2, object arg3)
  41. {
  42. _name = name;
  43. _arg1 = arg1;
  44. _arg2 = arg2;
  45. _arg3 = arg3;
  46. }
  47. public Functor3(string name, object arg1, object arg2, object arg3)
  48. : this(Atom.a(name), arg1, arg2, arg3)
  49. {
  50. }
  51. // disable warning on l1, don't see how we can
  52. // code this differently
  53. #pragma warning disable 0168, 0219
  54. /// If arg is another Functor3, then succeed (yield once) if this and arg have the
  55. /// same name and all functor args unify, otherwise fail (don't yield).
  56. /// If arg is a Variable, then call its unify to unify with this.
  57. /// Otherwise fail (don't yield).
  58. public IEnumerable<bool> unify(object arg)
  59. {
  60. arg = YP.getValue(arg);
  61. if (arg is Functor3)
  62. {
  63. Functor3 argFunctor = (Functor3)arg;
  64. if (_name.Equals(argFunctor._name))
  65. {
  66. foreach (bool l1 in YP.unify(_arg1, argFunctor._arg1))
  67. {
  68. foreach (bool l2 in YP.unify(_arg2, argFunctor._arg2))
  69. {
  70. foreach (bool l3 in YP.unify(_arg3, argFunctor._arg3))
  71. yield return false;
  72. }
  73. }
  74. }
  75. }
  76. else if (arg is Variable)
  77. {
  78. foreach (bool l1 in ((Variable)arg).unify(this))
  79. yield return false;
  80. }
  81. }
  82. #pragma warning restore 0168, 0219
  83. public override string ToString()
  84. {
  85. return _name + "(" + YP.getValue(_arg1) + ", " + YP.getValue(_arg2) + ", " +
  86. YP.getValue(_arg3) + ")";
  87. }
  88. public bool termEqual(object term)
  89. {
  90. term = YP.getValue(term);
  91. if (term is Functor3)
  92. {
  93. Functor3 termFunctor = (Functor3)term;
  94. return _name.Equals(termFunctor._name) && YP.termEqual(_arg1, termFunctor._arg1)
  95. && YP.termEqual(_arg2, termFunctor._arg2)
  96. && YP.termEqual(_arg3, termFunctor._arg3);
  97. }
  98. return false;
  99. }
  100. public bool lessThan(Functor3 functor)
  101. {
  102. // Do the equal check first since it is faster.
  103. if (!_name.Equals(functor._name))
  104. return _name.lessThan(functor._name);
  105. if (!YP.termEqual(_arg1, functor._arg1))
  106. return YP.termLessThan(_arg1, functor._arg1);
  107. if (!YP.termEqual(_arg2, functor._arg2))
  108. return YP.termLessThan(_arg2, functor._arg2);
  109. return YP.termLessThan(_arg3, functor._arg3);
  110. }
  111. public bool ground()
  112. {
  113. return YP.ground(_arg1) && YP.ground(_arg2) && YP.ground(_arg3);
  114. }
  115. public void addUniqueVariables(List<Variable> variableSet)
  116. {
  117. YP.addUniqueVariables(_arg1, variableSet);
  118. YP.addUniqueVariables(_arg2, variableSet);
  119. YP.addUniqueVariables(_arg3, variableSet);
  120. }
  121. public object makeCopy(Variable.CopyStore copyStore)
  122. {
  123. return new Functor3(_name, YP.makeCopy(_arg1, copyStore),
  124. YP.makeCopy(_arg2, copyStore), YP.makeCopy(_arg3, copyStore));
  125. }
  126. }
  127. }