/interpreter/tags/at2dist110511/src/edu/vub/at/objects/natives/grammar/AGAssignVariable.java

http://ambienttalk.googlecode.com/ · Java · 123 lines · 61 code · 16 blank · 46 comment · 0 complexity · 536de748807f504177930a27df3bd3c1 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * AGAssignVariable.java created on 26-jul-2006 at 15:54:48
  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.InvocationStack;
  30. import edu.vub.at.exceptions.InterpreterException;
  31. import edu.vub.at.exceptions.XTypeMismatch;
  32. import edu.vub.at.objects.ATContext;
  33. import edu.vub.at.objects.ATObject;
  34. import edu.vub.at.objects.grammar.ATAssignVariable;
  35. import edu.vub.at.objects.grammar.ATExpression;
  36. import edu.vub.at.objects.grammar.ATSymbol;
  37. import edu.vub.at.objects.natives.NATTable;
  38. import edu.vub.at.objects.natives.NATText;
  39. import edu.vub.util.TempFieldGenerator;
  40. import java.util.HashMap;
  41. import java.util.Set;
  42. /**
  43. * The native implementation of a variable assignment AG element.
  44. *
  45. * @author tvc
  46. */
  47. public final class AGAssignVariable extends NATAbstractGrammar implements ATAssignVariable {
  48. private final ATSymbol variableName_;
  49. private final ATExpression valueExp_;
  50. public AGAssignVariable(ATSymbol nam, ATExpression val) {
  51. variableName_ = nam;
  52. valueExp_ = val;
  53. }
  54. public ATSymbol base_name() { return variableName_; }
  55. public ATExpression base_valueExpression() { return valueExp_; }
  56. /**
  57. * To evaluate a variable assignment, evaluate the right hand side and ask
  58. * the current object to assign that value to the field corresponding to the left hand side.
  59. *
  60. * AGASSVAR(nam,val).eval(ctx) = ctx.scope.assignVariable(nam, val.eval(ctx))
  61. *
  62. * @return the value assigned to the variable
  63. */
  64. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  65. NATTable arg = NATTable.of(valueExp_.meta_eval(ctx));
  66. ATObject result = null;
  67. InvocationStack stack = InvocationStack.getInvocationStack();
  68. try {
  69. stack.functionCalled(this, null, arg);
  70. result = ctx.base_lexicalScope().impl_callMutator(variableName_.asAssignmentSymbol(), arg);
  71. } finally {
  72. stack.funcallReturned(result);
  73. }
  74. return result;
  75. }
  76. /**
  77. * AGASSVAR(nam,val).quote(ctx) = AGASSVAR(nam.quote(ctx), val.quote(ctx))
  78. */
  79. public ATObject meta_quote(ATContext ctx) throws InterpreterException {
  80. return new AGAssignVariable(variableName_.meta_quote(ctx).asSymbol(), valueExp_.meta_quote(ctx).asExpression());
  81. }
  82. public NATText meta_print() throws InterpreterException {
  83. return NATText.atValue(variableName_.meta_print().javaValue + " := " + valueExp_.meta_print().javaValue);
  84. }
  85. public NATText impl_asUnquotedCode(TempFieldGenerator objectMap) throws InterpreterException {
  86. return NATText.atValue(variableName_.impl_asUnquotedCode(objectMap).javaValue + " := " + valueExp_.impl_asUnquotedCode(objectMap).javaValue);
  87. }
  88. public boolean isVariableAssignment() {
  89. return true;
  90. }
  91. public ATAssignVariable asVariableAssignment() throws XTypeMismatch {
  92. return this;
  93. }
  94. /**
  95. * FV(var := valExp) = { var } U FV(valExp)
  96. */
  97. public Set impl_freeVariables() throws InterpreterException {
  98. Set fvValExp = valueExp_.impl_freeVariables();
  99. fvValExp.add(variableName_);
  100. return fvValExp;
  101. }
  102. public Set impl_quotedFreeVariables() throws InterpreterException {
  103. Set qfv = valueExp_.impl_quotedFreeVariables();
  104. qfv.addAll(variableName_.impl_quotedFreeVariables());
  105. return qfv;
  106. }
  107. }