Class MethodExpression


  • public class MethodExpression
    extends Expression
    an expression which identifies a method invocation
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      java.lang.reflect.Method bestMatchCandidate​(java.util.List<java.lang.reflect.Method> candidates, Type expected)
      return the method whose signature is the best fit for the call argument types.
      void bind()
      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
      void compile​(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext)  
      private void findMethod​(boolean publicOnly, Type expected)
      find a method to resolve this method call expression.
      java.lang.Class getCandidateArgClass​(java.util.List<java.lang.reflect.Method> candidates, int argIdx)  
      private java.lang.String getDescriptor()  
      java.lang.String getPath​(int len)  
      int getPathCount​(java.lang.String name)  
      java.lang.Object interpret​(HelperAdapter helper)
      evaluate the expression by interpreting the expression tree
      java.util.List<java.lang.reflect.Method> pruneCandidates​(java.util.List<java.lang.reflect.Method> candidates, int argIdx, java.lang.Class argClazz)
      prune the candidates list removing all methods whose parameter at index argIdx cannot be assigned to class argClazz
      Type typeCheck​(Type expected)
      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.
      void writeTo​(java.io.StringWriter stringWriter)  
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • setTriggeringMethod

        public static java.lang.reflect.Method setTriggeringMethod
      • name

        private java.lang.String name
      • arguments

        private java.util.List<Expression> arguments
      • argumentTypes

        private java.util.List<Type> argumentTypes
      • paramTypes

        private java.util.List<Type> paramTypes
      • rootType

        private Type rootType
      • method

        private java.lang.reflect.Method method
      • pathList

        java.lang.String[] pathList
      • methodIndex

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

        private boolean isPublicMethod
    • Constructor Detail

    • Method Detail

      • 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 java.lang.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
      • getDescriptor

        private java.lang.String getDescriptor()
      • getCandidateArgClass

        public java.lang.Class getCandidateArgClass​(java.util.List<java.lang.reflect.Method> candidates,
                                                    int argIdx)
      • pruneCandidates

        public java.util.List<java.lang.reflect.Method> pruneCandidates​(java.util.List<java.lang.reflect.Method> candidates,
                                                                        int argIdx,
                                                                        java.lang.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 java.lang.reflect.Method bestMatchCandidate​(java.util.List<java.lang.reflect.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 java.lang.String getPath​(int len)
      • getPathCount

        public int getPathCount​(java.lang.String name)
      • writeTo

        public void writeTo​(java.io.StringWriter stringWriter)
        Specified by:
        writeTo in class Expression