/interpreter/tags/at2dist220411/src/edu/vub/at/objects/natives/grammar/AGClosureLiteral.java

http://ambienttalk.googlecode.com/ · Java · 142 lines · 75 code · 15 blank · 52 comment · 2 complexity · 7c97377295724fe63daace5564d5f088 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * AGClosureLiteral.java created on 26-jul-2006 at 16:59:04
  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.objects.ATContext;
  32. import edu.vub.at.objects.ATObject;
  33. import edu.vub.at.objects.ATTable;
  34. import edu.vub.at.objects.grammar.ATBegin;
  35. import edu.vub.at.objects.grammar.ATClosureLiteral;
  36. import edu.vub.at.objects.mirrors.NativeClosure;
  37. import edu.vub.at.objects.natives.NATClosure;
  38. import edu.vub.at.objects.natives.NATMethod;
  39. import edu.vub.at.objects.natives.NATTable;
  40. import edu.vub.at.objects.natives.NATText;
  41. import edu.vub.util.TempFieldGenerator;
  42. import java.util.Set;
  43. /**
  44. * The native implementation of a literal closure AG element.
  45. *
  46. * @author tvc
  47. */
  48. public final class AGClosureLiteral extends AGExpression implements ATClosureLiteral {
  49. protected final ATTable arguments_;
  50. protected final ATBegin body_;
  51. private NATMethod preprocessedMethod_;
  52. public AGClosureLiteral(ATTable args, ATBegin body) throws InterpreterException {
  53. arguments_ = args;
  54. body_ = body;
  55. }
  56. public ATTable base_arguments() { return arguments_; }
  57. public ATBegin base_bodyExpression() { return body_; }
  58. /**
  59. * To evaluate a closure literal, construct a closure pairing the literal's arguments and body with the
  60. * current evaluation context.
  61. *
  62. * AGCLOLIT(arg,bdy).eval(ctx) = AGCLO(AGMTH("lambda",arg,bdy), ctx)
  63. *
  64. * @return a native closure closing over the current evaluation context.
  65. */
  66. public ATObject meta_eval(ATContext ctx) throws InterpreterException {
  67. // the method is not yet created in the constructor because this gives problems
  68. // with quoted parameters: a quoted parameter would result in an illegal parameter
  69. // exception while actually the block was defined in the context of a quotation,
  70. // so at runtime the block would have never been evaluated (but quoted instead)
  71. if (preprocessedMethod_ == null) {
  72. preprocessedMethod_ = new NATMethod(Evaluator._LAMBDA_, arguments_, body_, NATTable.EMPTY);
  73. preprocessedMethod_.impl_setLocation(this.impl_getLocation());
  74. }
  75. return new NATClosure(preprocessedMethod_, ctx);
  76. }
  77. /**
  78. * Quoting a closure literal results in a new quoted closure literal.
  79. *
  80. * AGCLOLIT(arg,bdy).quote(ctx) = AGCLOLIT(arg.quote(ctx), bdy.quote(ctx))
  81. */
  82. public ATObject meta_quote(ATContext ctx) throws InterpreterException {
  83. return new AGClosureLiteral(arguments_.meta_quote(ctx).asTable(),
  84. body_.meta_quote(ctx).asBegin());
  85. }
  86. public NATText meta_print() throws InterpreterException {
  87. return arguments_.base_isEmpty().base_ifTrue_ifFalse_(
  88. new NativeClosure(this) {
  89. public ATObject base_apply(ATTable args) throws InterpreterException {
  90. return NATText.atValue("{ "+ body_.meta_print().javaValue + " }");
  91. }
  92. },
  93. new NativeClosure(this) {
  94. public ATObject base_apply(ATTable args) throws InterpreterException {
  95. return NATText.atValue(Evaluator.printElements(arguments_.asNativeTable(), "{ |", ",", "| ").javaValue +
  96. body_.meta_print().javaValue+"}");
  97. }
  98. }).asNativeText();
  99. }
  100. public NATText impl_asUnquotedCode(final TempFieldGenerator objectMap) throws InterpreterException {
  101. return arguments_.base_isEmpty().base_ifTrue_ifFalse_(
  102. new NativeClosure(this) {
  103. public ATObject base_apply(ATTable args) throws InterpreterException {
  104. return NATText.atValue("{ "+ body_.impl_asUnquotedCode(objectMap).javaValue + " }");
  105. }
  106. },
  107. new NativeClosure(this) {
  108. public ATObject base_apply(ATTable args) throws InterpreterException {
  109. return NATText.atValue("{" + Evaluator.codeAsParameterList(objectMap, arguments_.asNativeTable()).javaValue +
  110. body_.impl_asUnquotedCode(objectMap).javaValue+"}");
  111. }
  112. }).asNativeText();
  113. }
  114. /**
  115. * FV({ |args| body }) = FV(optionalArgExps) U (FV(body) \ { args })
  116. */
  117. public Set impl_freeVariables() throws InterpreterException {
  118. Set fvBody = body_.impl_freeVariables();
  119. Evaluator.processFreeVariables(fvBody, arguments_);
  120. return fvBody;
  121. }
  122. public Set impl_quotedFreeVariables() throws InterpreterException {
  123. Set qfv = arguments_.impl_quotedFreeVariables();
  124. qfv.addAll(body_.impl_quotedFreeVariables());
  125. return qfv;
  126. }
  127. }