/interpreter/tags/at2dist041108/src/edu/vub/at/objects/natives/grammar/AGDefExternalField.java

http://ambienttalk.googlecode.com/ · Java · 122 lines · 56 code · 14 blank · 52 comment · 0 complexity · 3c4f330c45e644cb2b0bafa06ded7d74 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * AGDefExternalField.java created on 16-nov-2006 at 8:31:45
  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. */
  28. package edu.vub.at.objects.natives.grammar;
  29. import edu.vub.at.eval.Evaluator;
  30. import edu.vub.at.exceptions.InterpreterException;
  31. import edu.vub.at.exceptions.XIllegalOperation;
  32. import edu.vub.at.objects.ATContext;
  33. import edu.vub.at.objects.ATObject;
  34. import edu.vub.at.objects.grammar.ATDefExternalField;
  35. import edu.vub.at.objects.grammar.ATDefinition;
  36. import edu.vub.at.objects.grammar.ATExpression;
  37. import edu.vub.at.objects.grammar.ATSymbol;
  38. import edu.vub.at.objects.natives.NATText;
  39. import java.util.HashSet;
  40. import java.util.Set;
  41. /**
  42. * Represents the abstract grammar for defining external fields.
  43. *
  44. * @author tvcutsem
  45. */
  46. public class AGDefExternalField extends AGDefinition implements ATDefExternalField {
  47. private final ATSymbol rcvNam_;
  48. private final ATSymbol name_;
  49. private final ATExpression valueExp_;
  50. public AGDefExternalField(ATSymbol rcv, ATSymbol name, ATExpression value) {
  51. rcvNam_ = rcv;
  52. name_ = name;
  53. valueExp_ = value;
  54. }
  55. public ATSymbol base_receiver() { return rcvNam_; }
  56. public ATSymbol base_name() { return name_; }
  57. public ATExpression base_valueExpression() { return valueExp_; }
  58. /**
  59. * Defines a new field in the object denoted by the receiver symbol.
  60. * The return value is the value of the field.
  61. *
  62. * AGDEFEXTFLD(rcv,nam,val).eval(ctx) =
  63. * rcv.eval(ctx).addField(nam, val.eval(ctx))
  64. *
  65. * @throws XIllegalOperation if the receiver is an instance of a native type (whose field maps are sealed).
  66. */
  67. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  68. ATObject receiver = rcvNam_.meta_eval(ctx);
  69. ATObject val = valueExp_.meta_eval(ctx);
  70. receiver.meta_defineField(name_, val);
  71. return val;
  72. }
  73. /**
  74. * Quoting an external field definition results in a new quoted external field definition.
  75. *
  76. * AGDEFEXTFLD(rcv,nam,val).quote(ctx) = AGDEFEXTFLD(rcv.quote(ctx), nam.quote(ctx), val.quote(ctx))
  77. */
  78. public ATObject meta_quote(ATContext ctx) throws InterpreterException {
  79. return new AGDefExternalField(rcvNam_.meta_quote(ctx).asSymbol(),
  80. name_.meta_quote(ctx).asSymbol(),
  81. valueExp_.meta_quote(ctx).asExpression());
  82. }
  83. public NATText meta_print() throws InterpreterException {
  84. return NATText.atValue("def " + rcvNam_.meta_print().javaValue
  85. + "." + name_.meta_print().javaValue
  86. + " := " + valueExp_.meta_print().javaValue);
  87. }
  88. /**
  89. * IV(def o.x := val) = { }
  90. */
  91. public Set impl_introducedVariables() throws InterpreterException {
  92. return new HashSet();
  93. }
  94. /**
  95. * FV(def o.x := val) = FV(val) U { o }
  96. */
  97. public Set impl_freeVariables() throws InterpreterException {
  98. Set fvValueExp = valueExp_.impl_freeVariables();
  99. fvValueExp.add(rcvNam_);
  100. return fvValueExp;
  101. }
  102. public Set impl_quotedFreeVariables() throws InterpreterException {
  103. Set qfv = valueExp_.impl_quotedFreeVariables();
  104. qfv.addAll(rcvNam_.impl_quotedFreeVariables());
  105. qfv.addAll(name_.impl_quotedFreeVariables());
  106. return qfv;
  107. }
  108. }