/interpreter/tags/reactive-pattern-matching/src/edu/vub/at/objects/natives/grammar/AGDefExternalMethod.java

http://ambienttalk.googlecode.com/ · Java · 164 lines · 89 code · 22 blank · 53 comment · 7 complexity · 9d363e244c80e20ddac44b92407d1d7e MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * AGDefExternalMethod.java created on 15-nov-2006 at 19:33:18
  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.ATMethod;
  34. import edu.vub.at.objects.ATObject;
  35. import edu.vub.at.objects.ATTable;
  36. import edu.vub.at.objects.ATTypeTag;
  37. import edu.vub.at.objects.coercion.NativeTypeTags;
  38. import edu.vub.at.objects.grammar.ATBegin;
  39. import edu.vub.at.objects.grammar.ATDefExternalMethod;
  40. import edu.vub.at.objects.grammar.ATExpression;
  41. import edu.vub.at.objects.grammar.ATSymbol;
  42. import edu.vub.at.objects.natives.NATClosureMethod;
  43. import edu.vub.at.objects.natives.NATMethod;
  44. import edu.vub.at.objects.natives.NATTable;
  45. import edu.vub.at.objects.natives.NATText;
  46. /**
  47. * The native implementation of an external method definition abstract grammar element.
  48. *
  49. * @author tvcutsem
  50. */
  51. public final class AGDefExternalMethod extends NATAbstractGrammar implements ATDefExternalMethod {
  52. private final ATSymbol rcvNam_;
  53. private final ATSymbol selectorExp_;
  54. private final ATTable argumentExps_;
  55. private final ATBegin bodyStmts_;
  56. private final ATExpression annotationExps_;
  57. private ATMethod preprocessedMethod_;
  58. public AGDefExternalMethod(ATSymbol rcv, ATSymbol sel, ATTable args, ATBegin bdy, ATExpression ann)
  59. throws InterpreterException {
  60. rcvNam_ = rcv;
  61. selectorExp_ = sel;
  62. argumentExps_ = args;
  63. bodyStmts_ = bdy;
  64. annotationExps_ = ann;
  65. }
  66. public ATSymbol base_receiver() {
  67. return rcvNam_;
  68. }
  69. public ATSymbol base_selector() {
  70. return selectorExp_;
  71. }
  72. public ATTable base_arguments() {
  73. return argumentExps_;
  74. }
  75. public ATBegin base_bodyExpression() {
  76. return bodyStmts_;
  77. }
  78. public ATExpression base_annotationExpression() {
  79. return annotationExps_;
  80. }
  81. /**
  82. * Evaluates the receiver symbol to an object to which a new 'closure method' will be added.
  83. * Such a closure captures the current lexical scope, but not the values for 'self' and 'super'.
  84. *
  85. * The return value of an external method definition is always the external method itself.
  86. *
  87. * AGDEFEXTMTH(rcv,nam,par,bdy).eval(ctx) =
  88. * rcv.eval(ctx).defineField(nam, NATCLOMTH(ctx.cur,nam,par,bdy))
  89. *
  90. * @throws XIllegalOperation if the receiver is an instance of a native
  91. * type (whose method dictionaries are sealed) or if the receiver is an isolate.
  92. */
  93. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  94. // the method is not yet created in the constructor because this gives problems
  95. // with quoted parameters: a quoted parameter would result in an illegal parameter
  96. // exception while actually the external method was defined in the context of a quotation,
  97. // so at runtime the external definition would have never been evaluated (but quoted instead)
  98. if (preprocessedMethod_ == null) {
  99. ATObject oneOrMoreAnnotation = annotationExps_.meta_eval(ctx);
  100. ATTable annotationTable;
  101. if(oneOrMoreAnnotation.isTable()) {
  102. annotationTable = oneOrMoreAnnotation.asTable();
  103. } else {
  104. annotationTable = NATTable.of(oneOrMoreAnnotation);
  105. }
  106. preprocessedMethod_ = new NATMethod(selectorExp_, argumentExps_, bodyStmts_, annotationTable);
  107. ATObject[] annotations = annotationTable.asNativeTable().elements_;
  108. for (int i = 0; i < annotations.length; i++) {
  109. ATTypeTag theAnnotation = annotations[i].asTypeTag();
  110. preprocessedMethod_ = theAnnotation.base_annotateMethod(preprocessedMethod_);
  111. }
  112. }
  113. ATObject receiver = rcvNam_.meta_eval(ctx);
  114. if (receiver.meta_isTaggedAs(NativeTypeTags._ISOLATE_).asNativeBoolean().javaValue) {
  115. throw new XIllegalOperation("Cannot define external methods on isolates");
  116. } else {
  117. NATClosureMethod extMethod = new NATClosureMethod(ctx.base_lexicalScope(),
  118. preprocessedMethod_);
  119. receiver.meta_addMethod(extMethod);
  120. return extMethod;
  121. }
  122. }
  123. /**
  124. * Quoting an external method definition results in a new quoted external method definition.
  125. *
  126. * AGDEFEXTMTH(rcv,nam,par,bdy).quote(ctx) = AGDEFEXTMTH(rcv.quote(ctx),nam.quote(ctx), par.quote(ctx), bdy.quote(ctx))
  127. */
  128. public ATObject meta_quote(ATContext ctx) throws InterpreterException {
  129. return new AGDefExternalMethod(rcvNam_.meta_quote(ctx).asSymbol(),
  130. selectorExp_.meta_quote(ctx).asSymbol(),
  131. argumentExps_.meta_quote(ctx).asTable(),
  132. bodyStmts_.meta_quote(ctx).asBegin(),
  133. annotationExps_.meta_quote(ctx).asExpression());
  134. }
  135. public NATText meta_print() throws InterpreterException {
  136. return NATText.atValue("def " +
  137. rcvNam_.meta_print().javaValue + "." +
  138. selectorExp_.meta_print().javaValue +
  139. Evaluator.printAsList(argumentExps_).javaValue +
  140. " { " + bodyStmts_.meta_print().javaValue + " }");
  141. }
  142. }