/interpreter/tags/at2dist091109/src/edu/vub/at/objects/natives/NATField.java

http://ambienttalk.googlecode.com/ · Java · 145 lines · 86 code · 17 blank · 42 comment · 3 complexity · 3b70d7b3ec3737f391028944ff0f16a5 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * NATField.java created on Jul 27, 2006 at 2:27:53 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.natives;
  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.exceptions.XSelectorNotFound;
  33. import edu.vub.at.exceptions.XTypeMismatch;
  34. import edu.vub.at.objects.ATContext;
  35. import edu.vub.at.objects.ATField;
  36. import edu.vub.at.objects.ATMethod;
  37. import edu.vub.at.objects.ATObject;
  38. import edu.vub.at.objects.ATTable;
  39. import edu.vub.at.objects.coercion.NativeTypeTags;
  40. import edu.vub.at.objects.grammar.ATSymbol;
  41. import edu.vub.at.objects.mirrors.PrimitiveMethod;
  42. import edu.vub.at.objects.natives.grammar.AGSymbol;
  43. /**
  44. * NATField implements a causally connected field of an object. Rather than storing
  45. * these fields directly in every object, we choose to only make people pay when they
  46. * choose to reify them.
  47. *
  48. * @author smostinc, tvcutsem
  49. */
  50. public class NATField extends NATByRef implements ATField {
  51. private final ATSymbol name_;
  52. private final ATObject host_;
  53. /**
  54. * Constructs a new native field object linked to the field of a base-level
  55. * AmbientTalk object
  56. */
  57. public NATField(ATSymbol name, ATObject host) {
  58. name_ = name;
  59. host_ = host;
  60. }
  61. public ATSymbol base_name() {
  62. return name_;
  63. }
  64. public ATObject base_readField() throws InterpreterException {
  65. return host_.meta_invokeField(host_, name_);
  66. }
  67. public ATObject base_writeField(ATObject newValue) throws InterpreterException {
  68. return host_.impl_invoke(host_, name_.asAssignmentSymbol(), NATTable.of(newValue));
  69. }
  70. public NATText meta_print() throws InterpreterException {
  71. return NATText.atValue("<field:"+name_.meta_print().javaValue+">");
  72. }
  73. public boolean isNativeField() {
  74. return true;
  75. }
  76. public ATField asField() throws XTypeMismatch {
  77. return this;
  78. }
  79. /**
  80. * Fields can be re-initialized when installed in an object that is being cloned.
  81. * They expect the new owner of the field as the sole instance to their 'new' method
  82. */
  83. public ATObject meta_newInstance(ATTable initargs) throws InterpreterException {
  84. if (initargs.base_length() != NATNumber.ONE) {
  85. return super.meta_newInstance(initargs);
  86. } else {
  87. ATObject newhost = initargs.base_at(NATNumber.ONE);
  88. return new NATField(name_, (NATCallframe) newhost);
  89. }
  90. }
  91. public ATTable meta_typeTags() throws InterpreterException {
  92. return NATTable.of(NativeTypeTags._FIELD_);
  93. }
  94. public ATMethod base_accessor() throws InterpreterException {
  95. return accessorForField(this);
  96. }
  97. public ATMethod base_mutator() throws InterpreterException {
  98. return mutatorForField(this);
  99. }
  100. public static ATMethod accessorForField(final ATField f) throws InterpreterException {
  101. return new PrimitiveMethod(f.base_name(), NATTable.EMPTY, new PrimitiveMethod.PrimitiveBody() {
  102. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  103. return f.base_readField();
  104. }
  105. public NATText meta_print() throws InterpreterException {
  106. return NATText.atValue(f.base_readField().toString());
  107. }
  108. }) {
  109. public NATText meta_print() throws InterpreterException {
  110. return NATText.atValue("<accessor method for:"+f.base_name()+">");
  111. }
  112. };
  113. }
  114. public static ATMethod mutatorForField(final ATField f) throws InterpreterException {
  115. return new PrimitiveMethod(f.base_name().asAssignmentSymbol(), NATTable.of(AGSymbol.jAlloc("v")), new PrimitiveMethod.PrimitiveBody() {
  116. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  117. return f.base_writeField(ctx.base_lexicalScope().impl_callField(AGSymbol.jAlloc("v")));
  118. }
  119. public NATText meta_print() throws InterpreterException {
  120. return NATText.atValue(""+f.base_name()+" := v");
  121. }
  122. }) {
  123. public NATText meta_print() throws InterpreterException {
  124. return NATText.atValue("<mutator method for:"+f.base_name()+">");
  125. }
  126. };
  127. }
  128. }