org.jboss.byteman.rule.expression
Class ReturnExpression

java.lang.Object
  extended by org.jboss.byteman.rule.RuleElement
      extended by org.jboss.byteman.rule.expression.Expression
          extended by org.jboss.byteman.rule.expression.ReturnExpression

public class ReturnExpression
extends Expression

A return expression which is used in a rule action to cause a return from the rule trigger method, supplying a return value where appropriate.


Field Summary
private  Expression returnValue
           
 
Fields inherited from class org.jboss.byteman.rule.expression.Expression
charPos, line, rule, token, type
 
Constructor Summary
ReturnExpression(Rule rule, ParseNode token, Expression returnValue)
           
 
Method Summary
 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(MethodVisitor mv, CompileContext compileContext)
           
 java.lang.Object interpret(HelperAdapter helper)
          evaluate the expression by interpreting the expression tree
 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 org.jboss.byteman.rule.expression.Expression
getPos, getType
 
Methods inherited from class org.jboss.byteman.rule.RuleElement
compileBooleanConversion, compileBox, compileNumericConversion, compileObjectConversion, compilePrimitiveConversion, compileStringConversion, compileTypeConversion, compileUnbox, getBindings, getTypeGroup, toString
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

returnValue

private Expression returnValue
Constructor Detail

ReturnExpression

public ReturnExpression(Rule rule,
                        ParseNode token,
                        Expression returnValue)
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

typeCheck

public Type typeCheck(Type expected)
               throws TypeException
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 contxt in which it occurs. this may be void but shoudl not be undefined at the point where type checking is performed.
Returns:
Throws:
TypeException

interpret

public java.lang.Object interpret(HelperAdapter helper)
                           throws ExecuteException
evaluate the expression by interpreting the expression tree

Specified by:
interpret in class Expression
Parameters:
helper - an execution context associated with the rule whcih contains a map of current bindings for rule variables and another map of their declared types both of which are indexed by varoable 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

compile

public void compile(MethodVisitor mv,
                    CompileContext compileContext)
             throws CompileException
Specified by:
compile in class RuleElement
Throws:
CompileException

writeTo

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