Class FieldExpression


  • public class FieldExpression
    extends AssignableExpression
    an expression which identifies an instance field reference
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      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 bindAssign()
      treat this as a normal bind because an update to a field reference does not update any bindings
      private void checkIndirectStatic()  
      void compile​(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext)  
      void compileAssign​(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext)
      compile an assignment to the referenced location using the value on the top of the Java stack.
      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.lang.Object interpretAssign​(HelperAdapter helperAdapter, java.lang.Object value)
      execute an assignment to the referenced location by interpretation of the expression, using the object passed in this call
      private java.lang.reflect.Field lookupField​(java.lang.Class<?> ownerClazz, boolean isAssign)  
      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.
      private void typeCheckAny​(boolean isAssign)  
      Type typeCheckAssign​(Type expected)
      typecheck the expression as an lvalue of an assignment operation
      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

      • pathList

        private java.lang.String[] pathList
      • fieldName

        private java.lang.String fieldName
      • ownerType

        private Type ownerType
      • field

        private java.lang.reflect.Field field
      • isArrayLength

        private boolean isArrayLength
      • isClassAccess

        private boolean isClassAccess
      • isPublicField

        private boolean isPublicField
        true if this is a public field otherwise false
      • fieldIndex

        private int fieldIndex
        index used compiled code when reading or writing a non-public field to obtain the field descriptor from the helper's list of accessible field descriptors.
    • Constructor Detail

      • FieldExpression

        public FieldExpression​(Rule rule,
                               Type type,
                               ParseNode fieldTree,
                               java.lang.String fieldName,
                               Expression owner,
                               java.lang.String[] pathList)
    • 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
      • bindAssign

        public void bindAssign()
                        throws TypeException
        treat this as a normal bind because an update to a field reference does not update any bindings
        Specified by:
        bindAssign in class AssignableExpression
        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
      • 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
      • 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
      • interpretAssign

        public java.lang.Object interpretAssign​(HelperAdapter helperAdapter,
                                                java.lang.Object value)
                                         throws ExecuteException
        Description copied from class: AssignableExpression
        execute an assignment to the referenced location by interpretation of the expression, using the object passed in this call
        Specified by:
        interpretAssign in class AssignableExpression
        Parameters:
        helperAdapter - 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", ...)
        value - the value to be assigned to this object
        Returns:
        the result of evaluation as an Object
        Throws:
        ExecuteException - if an error occurs during execution
      • lookupField

        private java.lang.reflect.Field lookupField​(java.lang.Class<?> ownerClazz,
                                                    boolean isAssign)
                                             throws java.lang.NoSuchFieldException
        Throws:
        java.lang.NoSuchFieldException