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

http://ambienttalk.googlecode.com/ · Java · 170 lines · 82 code · 20 blank · 68 comment · 0 complexity · 62465119c48b90d1823ea4f93225d8b0 MD5 · raw file

  1. /**
  2. * AmbientTalk/2 Project
  3. * NATMethod.java created on Jul 24, 2006 at 11:30:35 PM
  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.PartialBinder;
  30. import edu.vub.at.exceptions.InterpreterException;
  31. import edu.vub.at.exceptions.XTypeMismatch;
  32. import edu.vub.at.objects.ATClosure;
  33. import edu.vub.at.objects.ATContext;
  34. import edu.vub.at.objects.ATMethod;
  35. import edu.vub.at.objects.ATObject;
  36. import edu.vub.at.objects.ATTable;
  37. import edu.vub.at.objects.coercion.NativeTypeTags;
  38. import edu.vub.at.objects.grammar.ATBegin;
  39. import edu.vub.at.objects.grammar.ATSymbol;
  40. import edu.vub.at.objects.mirrors.PrimitiveMethod;
  41. import edu.vub.at.util.logging.Logging;
  42. /**
  43. * NATMethod implements methods as named functions which are in fact simply containers
  44. * for a name, a table of arguments and a body.
  45. *
  46. * @author smostinc
  47. * @author tvcutsem
  48. */
  49. public class NATMethod extends NATByCopy implements ATMethod {
  50. private final ATSymbol name_;
  51. private final ATTable parameters_;
  52. private final ATBegin body_;
  53. private final ATTable annotations_;
  54. // partial function denoting a parameter binding algorithm specialized for this method's parameter list
  55. private final PartialBinder parameterBindingFunction_;
  56. /** construct a new method. This method may raise an exception if the parameter list is illegal. */
  57. public NATMethod(ATSymbol name, ATTable parameters, ATBegin body, ATTable annotations) throws InterpreterException {
  58. name_ = name;
  59. parameters_ = parameters;
  60. body_ = body;
  61. annotations_= annotations;
  62. // calculate the parameter binding strategy to use using partial evaluation
  63. parameterBindingFunction_ =
  64. PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters);
  65. }
  66. /**
  67. * Constructor to be used by primitive methods only.
  68. */
  69. protected NATMethod(ATSymbol name, ATTable parameters, PrimitiveMethod.PrimitiveBody body, ATTable annotations) {
  70. name_ = name;
  71. parameters_ = parameters;
  72. body_ = body;
  73. annotations_= annotations;
  74. PartialBinder parameterBindingFunction;
  75. try {
  76. // calculate the parameter binding strategy to use using partial evaluation
  77. parameterBindingFunction = PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters);
  78. } catch (InterpreterException e) {
  79. parameterBindingFunction = null;
  80. // this indicates a bug, primitive methods should not contain erroneous parameter lists
  81. Logging.VirtualMachine_LOG.fatal("error creating primitive method: ",e);
  82. }
  83. parameterBindingFunction_ = parameterBindingFunction;
  84. }
  85. public ATClosure base_wrap(ATObject lexicalScope, ATObject dynamicReceiver) throws InterpreterException {
  86. return new NATClosure(this, lexicalScope, dynamicReceiver);
  87. }
  88. public ATSymbol base_name() {
  89. return name_;
  90. }
  91. public ATTable base_parameters() {
  92. return parameters_;
  93. }
  94. public ATBegin base_bodyExpression() {
  95. return body_;
  96. }
  97. public ATTable base_annotations() throws InterpreterException {
  98. return annotations_;
  99. }
  100. /**
  101. * To apply a function, first bind its parameters to the evaluated arguments within a new call frame.
  102. * This call frame is lexically nested within the current lexical scope.
  103. *
  104. * This method is invoked via the following paths:
  105. * - either by directly 'calling a function', in which case this method is applied via NATClosure.base_apply.
  106. * The closure ensures that the context used is the lexical scope, not the dynamic scope of invocation.
  107. * - or by 'invoking a method' through an object, in which case this method is applied via NATObject.meta_invoke.
  108. * The enclosing object ensures that the context is properly initialized with the implementor, the dynamic receiver
  109. * and the implementor's parent.
  110. *
  111. * @param arguments the evaluated actual arguments
  112. * @param ctx the context in which to evaluate the method body, where a call frame will be inserted first
  113. * @return the value of evaluating the function body
  114. */
  115. public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
  116. NATCallframe cf = new NATCallframe(ctx.base_lexicalScope());
  117. ATContext evalCtx = ctx.base_withLexicalEnvironment(cf);
  118. PartialBinder.defineParamsForArgs(parameterBindingFunction_, evalCtx, arguments);
  119. return body_.meta_eval(evalCtx);
  120. }
  121. /**
  122. * Applies the method in the context given, without first inserting a call frame to bind parameters.
  123. * Arguments are bound directly in the given lexical scope.
  124. *
  125. * This method is often invoked via its enclosing closure when used to implement various language
  126. * constructs such as object:, mirror:, extend:with: etc.
  127. *
  128. * @param arguments the evaluated actual arguments
  129. * @param ctx the context in which to evaluate the method body, to be used as-is
  130. * @return the value of evaluating the function body
  131. */
  132. public ATObject base_applyInScope(ATTable arguments, ATContext ctx) throws InterpreterException {
  133. PartialBinder.defineParamsForArgs(parameterBindingFunction_, ctx, arguments);
  134. return body_.meta_eval(ctx);
  135. }
  136. public NATText meta_print() throws InterpreterException {
  137. return NATText.atValue("<method:"+name_.meta_print().javaValue+">");
  138. }
  139. public ATObject meta_clone() throws InterpreterException {
  140. return this;
  141. }
  142. public ATMethod asMethod() throws XTypeMismatch {
  143. return this;
  144. }
  145. public ATTable meta_typeTags() throws InterpreterException {
  146. return NATTable.atValue(NATTable.collate(
  147. new ATObject[] { NativeTypeTags._METHOD_, NativeTypeTags._ISOLATE_ },
  148. annotations_.asNativeTable().elements_));
  149. }
  150. }