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

http://ambienttalk.googlecode.com/ · Java · 188 lines · 95 code · 25 blank · 68 comment · 4 complexity · e5463bc1b682f5e842fc3e43c6f96d8c 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.signals.natives.NATLiftedBehavior;
  42. import edu.vub.at.util.logging.Logging;
  43. /**
  44. * NATMethod implements methods as named functions which are in fact simply containers
  45. * for a name, a table of arguments and a body.
  46. *
  47. * @author smostinc
  48. * @author tvcutsem
  49. */
  50. public class NATMethod extends NATByCopy implements ATMethod {
  51. private final ATSymbol name_;
  52. private final ATTable parameters_;
  53. private final ATBegin body_;
  54. private final ATTable annotations_;
  55. // partial function denoting a parameter binding algorithm specialized for this method's parameter list
  56. private final PartialBinder parameterBindingFunction_;
  57. /** construct a new method. This method may raise an exception if the parameter list is illegal. */
  58. public NATMethod(ATSymbol name, ATTable parameters, ATBegin body, ATTable annotations) throws InterpreterException {
  59. name_ = name;
  60. parameters_ = parameters;
  61. body_ = body;
  62. annotations_= annotations;
  63. // calculate the parameter binding strategy to use using partial evaluation
  64. parameterBindingFunction_ =
  65. PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters);
  66. }
  67. /**
  68. * Constructor to be used by primitive methods only.
  69. */
  70. protected NATMethod(ATSymbol name, ATTable parameters, PrimitiveMethod.PrimitiveBody body, ATTable annotations) {
  71. name_ = name;
  72. parameters_ = parameters;
  73. body_ = body;
  74. annotations_= annotations;
  75. PartialBinder parameterBindingFunction;
  76. try {
  77. // calculate the parameter binding strategy to use using partial evaluation
  78. parameterBindingFunction = PartialBinder.calculateResidual(name_.base_text().asNativeText().javaValue, parameters);
  79. } catch (InterpreterException e) {
  80. parameterBindingFunction = null;
  81. // this indicates a bug, primitive methods should not contain erroneous parameter lists
  82. Logging.VirtualMachine_LOG.fatal("error creating primitive method: ",e);
  83. }
  84. parameterBindingFunction_ = parameterBindingFunction;
  85. }
  86. public ATClosure base_wrap(ATObject lexicalScope, ATObject dynamicReceiver) throws InterpreterException {
  87. return new NATClosure(this, lexicalScope, dynamicReceiver);
  88. }
  89. public ATSymbol base_name() {
  90. return name_;
  91. }
  92. public ATTable base_parameters() {
  93. return parameters_;
  94. }
  95. public ATBegin base_bodyExpression() {
  96. return body_;
  97. }
  98. public ATTable base_annotations() throws InterpreterException {
  99. return annotations_;
  100. }
  101. /**
  102. * To apply a function, first bind its parameters to the evaluated arguments within a new call frame.
  103. * This call frame is lexically nested within the current lexical scope.
  104. *
  105. * This method is invoked via the following paths:
  106. * - either by directly 'calling a function', in which case this method is applied via NATClosure.base_apply.
  107. * The closure ensures that the context used is the lexical scope, not the dynamic scope of invocation.
  108. * - or by 'invoking a method' through an object, in which case this method is applied via NATObject.meta_invoke.
  109. * The enclosing object ensures that the context is properly initialized with the implementor, the dynamic receiver
  110. * and the implementor's parent.
  111. *
  112. * @param arguments the evaluated actual arguments
  113. * @param ctx the context in which to evaluate the method body, where a call frame will be inserted first
  114. * @return the value of evaluating the function body
  115. */
  116. public ATObject base_apply(ATTable arguments, ATContext ctx) throws InterpreterException {
  117. if(! base_annotations().base_contains(NativeTypeTags._LIFTED_).asNativeBoolean().javaValue) {
  118. boolean shouldBeLifted = false;
  119. ATObject[] argumentsArray = arguments.asNativeTable().elements_;
  120. for (int argIndex = 0; argIndex < argumentsArray.length; argIndex++) {
  121. ATObject currentArgument = argumentsArray[argIndex];
  122. if (currentArgument.isBehavior()) {
  123. shouldBeLifted = true;
  124. break;
  125. }
  126. }
  127. if(shouldBeLifted) {
  128. return NATLiftedBehavior.fromClosure(new NATClosure(this, ctx), argumentsArray);
  129. } // else
  130. }
  131. NATCallframe cf = new NATCallframe(ctx.base_lexicalScope());
  132. ATContext evalCtx = ctx.base_withLexicalEnvironment(cf);
  133. PartialBinder.defineParamsForArgs(parameterBindingFunction_, evalCtx, arguments);
  134. return body_.meta_eval(evalCtx);
  135. }
  136. /**
  137. * Applies the method in the context given, without first inserting a call frame to bind parameters.
  138. * Arguments are bound directly in the given lexical scope.
  139. *
  140. * This method is often invoked via its enclosing closure when used to implement various language
  141. * constructs such as object:, mirror:, extend:with: etc.
  142. *
  143. * @param arguments the evaluated actual arguments
  144. * @param ctx the context in which to evaluate the method body, to be used as-is
  145. * @return the value of evaluating the function body
  146. */
  147. public ATObject base_applyInScope(ATTable arguments, ATContext ctx) throws InterpreterException {
  148. PartialBinder.defineParamsForArgs(parameterBindingFunction_, ctx, arguments);
  149. return body_.meta_eval(ctx);
  150. }
  151. public NATText meta_print() throws InterpreterException {
  152. return NATText.atValue("<method:"+name_.meta_print().javaValue+">");
  153. }
  154. public ATObject meta_clone() throws InterpreterException {
  155. return this;
  156. }
  157. public ATMethod asMethod() throws XTypeMismatch {
  158. return this;
  159. }
  160. public ATTable meta_typeTags() throws InterpreterException {
  161. return NATTable.of(NativeTypeTags._METHOD_, NativeTypeTags._ISOLATE_);
  162. }
  163. }