Class FieldExpression


public class FieldExpression extends AssignableExpression
an expression which identifies an instance field reference
  • Field Details

    • owner

      private Expression owner
    • pathList

      private String[] pathList
    • fieldName

      private String fieldName
    • ownerType

      private Type ownerType
    • field

      private Field field
    • indirectStatic

      private AssignableExpression indirectStatic
    • 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 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
    • 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
    • typeCheckAssign

      public Type typeCheckAssign(Type expected) throws TypeException
      Description copied from class: AssignableExpression
      typecheck the expression as an lvalue of an assignment operation
      Specified by:
      typeCheckAssign in class AssignableExpression
      Parameters:
      expected - the expected type for the expression
      Returns:
      the expression type
      Throws:
      TypeException - if a type check error occurs
    • checkIndirectStatic

      private void checkIndirectStatic() throws TypeException
      Throws:
      TypeException
    • typeCheckAny

      private void typeCheckAny(boolean isAssign) throws TypeException
      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
    • getPath

      public String getPath(int len)
    • getPathCount

      public int getPathCount(String name)
    • writeTo

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

      public Object interpretAssign(HelperAdapter helperAdapter, 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
    • compileAssign

      public void compileAssign(org.objectweb.asm.MethodVisitor mv, CompileContext compileContext) throws CompileException
      Description copied from class: AssignableExpression
      compile an assignment to the referenced location using the value on the top of the Java stack.
      Specified by:
      compileAssign in class AssignableExpression
      Parameters:
      mv - the current method visitor
      compileContext - the current compile context
      Throws:
      CompileException - if a compile error occurs
    • lookupField

      private Field lookupField(Class<?> ownerClazz, boolean isAssign) throws NoSuchFieldException
      Throws:
      NoSuchFieldException