/interpreter/tags/at2dist090708/src/edu/vub/at/objects/natives/grammar/AGMessageSend.java

http://ambienttalk.googlecode.com/ · Java · 105 lines · 48 code · 11 blank · 46 comment · 0 complexity · 9c33f9a72237cdec20171fd2fda6b5d4 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * AGMessageSend.java created on 26-jul-2006 at 16:03:06
  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.eval.InvocationStack;
  31. import edu.vub.at.exceptions.InterpreterException;
  32. import edu.vub.at.objects.ATContext;
  33. import edu.vub.at.objects.ATMessage;
  34. import edu.vub.at.objects.ATNil;
  35. import edu.vub.at.objects.ATObject;
  36. import edu.vub.at.objects.ATTable;
  37. import edu.vub.at.objects.grammar.ATExpression;
  38. import edu.vub.at.objects.grammar.ATMessageSend;
  39. import edu.vub.at.objects.natives.NATText;
  40. /**
  41. * @author tvc
  42. *
  43. * The native implementation of a synchronous message send AG element.
  44. */
  45. public final class AGMessageSend extends AGExpression implements ATMessageSend {
  46. private ATExpression rcvExp_;
  47. private final ATExpression message_;
  48. public AGMessageSend(ATExpression rcv, ATExpression msg) {
  49. rcvExp_ = rcv;
  50. message_ = msg;
  51. }
  52. public ATExpression base_receiverExpression() { return rcvExp_; }
  53. public ATNil base_receiverExpression__opeql_(ATExpression rcv) {
  54. rcvExp_ = rcv;
  55. return Evaluator.getNil();
  56. }
  57. public ATExpression base_messageExpression() { return message_; }
  58. /**
  59. * To evaluate a message send, evaluate the receiver expression into an object.
  60. * Next, evaluate the message expression into a first-class message (asynchronous message or method invocation).
  61. * The evaluation of the message send is delegated to the first-class message itself.
  62. *
  63. * AGMSGSEND(rcv,msg).eval(ctx) = msg.eval(ctx).meta_sendTo(rcv.eval(ctx), ctx.self)
  64. *
  65. * @return the value of the invoked method or NIL in the case of an asynchronous message send.
  66. */
  67. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  68. ATMessage msg = message_.meta_eval(ctx).asMessage();
  69. ATObject rcvr = rcvExp_.meta_eval(ctx);
  70. ATObject result = null;
  71. InvocationStack stack = InvocationStack.getInvocationStack();
  72. ATTable args = msg.base_arguments();
  73. try {
  74. stack.methodInvoked(this, rcvr, args);
  75. result = msg.base_sendTo(rcvr, ctx.base_receiver());
  76. } finally {
  77. stack.methodReturned(result);
  78. }
  79. return result;
  80. }
  81. /**
  82. * Quoting a message send returns a new quoted message send.
  83. *
  84. * AGMSGSEND(rcv,msg).quote(ctx) = AGMSGSEND(rcv.quote(ctx), msg.quote(ctx))
  85. */
  86. public ATObject meta_quote(ATContext ctx) throws InterpreterException {
  87. return new AGMessageSend(rcvExp_.meta_quote(ctx).asExpression(),
  88. message_.meta_quote(ctx).asExpression());
  89. }
  90. public NATText meta_print() throws InterpreterException {
  91. return NATText.atValue(rcvExp_.meta_print().javaValue +
  92. ((message_.isMessageCreation()) ? "" : "<+") + message_.meta_print().javaValue);
  93. }
  94. }