Class MethodExpression


public class MethodExpression extends Expression
an expression which identifies a method invocation
  • Field Details

    • setTriggeringMethod

      public static Method setTriggeringMethod
    • name

      private String name
    • arguments

      private List<Expression> arguments
    • argumentTypes

      private List<Type> argumentTypes
    • paramTypes

      private List<Type> paramTypes
    • recipient

      private Expression recipient
    • rootType

      private Type rootType
    • method

      private Method method
    • pathList

      String[] pathList
    • methodIndex

      private int methodIndex
      index fo method object in rule's accessible method list
    • isPublicMethod

      private boolean isPublicMethod
  • Constructor Details

  • Method Details

    • bind

      public void bind() throws TypeException
      verify that variables mentioned in this expression are actually available in the supplied bindings list and infer/validate the type of this expression or its subexpressions where possible
      Specified by:
      bind in class Expression
      Throws:
      TypeException - if any variable is missing or has the wrong type
    • typeCheck

      public Type typeCheck(Type expected) throws TypeException
      Description copied from class: Expression
      ensure that all type references in the expression and its component expressions can be resolved, that the type of the expression is well-defined and that it is compatible with the type expected in the context in which it occurs.
      Specified by:
      typeCheck in class Expression
      Parameters:
      expected - the type expected for the expression in the contxet in which it occurs. this may be void but should not be undefined at the point where type checking is performed.
      Returns:
      the type of the expression
      Throws:
      TypeException - if a type check failure occurs
    • findMethod

      private void findMethod(boolean publicOnly, Type expected) throws TypeException
      find a method to resolve this method call expression.
      Parameters:
      publicOnly - true if only public methods should be considered
      Throws:
      TypeException
    • interpret

      public Object interpret(HelperAdapter helper) throws ExecuteException
      Description copied from class: Expression
      evaluate the expression by interpreting the expression tree
      Specified by:
      interpret in class Expression
      Parameters:
      helper - an execution context associated with the rule which contains a map of current bindings for rule variables and another map of their declared types both of which are indexed by variable name. This includes entries for the helper (name "-1"), the recipient if the trigger method is not static (name "0") and the trigger method arguments (names "1", ...)
      Returns:
      the result of evaluation as an Object
      Throws:
      ExecuteException - if an error occurs during execution
    • compile

      public void compile(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext) throws CompileException
      Specified by:
      compile in class RuleElement
      Throws:
      CompileException
    • getDescriptor

      private String getDescriptor()
    • getCandidateArgClass

      public Class getCandidateArgClass(List<Method> candidates, int argIdx)
    • pruneCandidates

      public List<Method> pruneCandidates(List<Method> candidates, int argIdx, Class argClazz)
      prune the candidates list removing all methods whose parameter at index argIdx cannot be assigned to class argClazz
      Parameters:
      candidates - candidate matching methods
      argIdx - index of arg curently being checked
      argClazz - class of arg curently being checked
      Returns:
      the pruned method list
    • bestMatchCandidate

      public Method bestMatchCandidate(List<Method> candidates, Type expected)
      return the method whose signature is the best fit for the call argument types. the selection is made by counting the number of cases where the argument type matches the parameter type exactly and then the number of cases where the argument type matches the parameter type without the need for type coercion (i.e. the parameter tyoe is a supertype of the argument type)
      Parameters:
      candidates - a list of methods all of whose signatures are assignable from the
      expected - an expected type which may or may not constrain the method return type
      Returns:
      the best match if there is a unique one otherwise NULL
    • getPath

      public String getPath(int len)
    • getPathCount

      public int getPathCount(String name)
    • writeTo

      public void writeTo(StringWriter stringWriter)
      Specified by:
      writeTo in class Expression