/interpreter/tags/at2dist110511/src/edu/vub/at/objects/ATField.java

http://ambienttalk.googlecode.com/ · Java · 81 lines · 10 code · 9 blank · 62 comment · 0 complexity · de539d5816837304bd2e921774ea2e16 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * ATField.java created on Jul 23, 2006 at 11:52:56 AM
  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;
  29. import edu.vub.at.exceptions.InterpreterException;
  30. import edu.vub.at.objects.grammar.ATSymbol;
  31. /**
  32. * ATField provides a mapping from an immutable name to a potentially mutable value.
  33. * <p>
  34. * Note that when field objects are added to an {@link ATObject} and then that object is cloned,
  35. * the field object will be re-instantiated (i.e. its 'new' method is invoked).
  36. * This implies that any object implementing ATField should provide a meta_newInstance
  37. * method whose sole initarg is the new host for the field.
  38. *
  39. * @author smostinc
  40. */
  41. public interface ATField extends ATObject {
  42. /**
  43. * Returns a string by which the slot can be identified.
  44. *
  45. * @return a {@link ATSymbol} representing the string by which the slot can be identified.
  46. */
  47. public ATSymbol base_name() throws InterpreterException;
  48. /**
  49. * Returns the current value of the field.
  50. *
  51. * @return an {@link ATObject} representing the current value of the field.
  52. * @throws XIllegalOperation if the field accessed is not found.
  53. */
  54. public ATObject base_readField() throws InterpreterException;
  55. /**
  56. * Sets the value of the field if possible.
  57. *
  58. * @param newValue the value the field should hold.
  59. * @return by default, the new value
  60. * @throws InterpreterException if the field cannot be modified.
  61. */
  62. public ATObject base_writeField(ATObject newValue) throws InterpreterException;
  63. /**
  64. * @return an accessor method (slot) that, upon invocation, reads this field's value.
  65. */
  66. public ATMethod base_accessor() throws InterpreterException;
  67. /**
  68. * @return a mutator method (slot) that, upon invocation, sets this field's value
  69. * to its single argument.
  70. */
  71. public ATMethod base_mutator() throws InterpreterException;
  72. }