org.objectweb.medor.filter.lib
Class IsEmpty

java.lang.Object
  |
  +--org.objectweb.medor.filter.lib.BasicUnaryOperator
        |
        +--org.objectweb.medor.filter.lib.IsEmpty
All Implemented Interfaces:
Cloneable, java.lang.Cloneable, Expression, Operator, UnaryOperator

public class IsEmpty
extends BasicUnaryOperator
implements UnaryOperator

IsEmpty operates on an Expression which must be of a TupleCollection type, or a GenClassRef. Its evaluation returns true if the Expression is an empty TupleCollection or if the GenClassRef has no element.


Field Summary
 
Fields inherited from class org.objectweb.medor.filter.lib.BasicUnaryOperator
result, subResult, type
 
Fields inherited from interface org.objectweb.medor.filter.api.Operator
ABS, AND, BITWIZE, CONCAT, CONDAND, CONDOR, DIV, EQUAL, FIRSTLOCATE, GREATER, GREATEREQUAL, IN, INDEXEDLOCATE, LENGTH, LOWER, LOWEREQUAL, MEMBEROF, MINUS, MULT, NAV, NOT, NOTEQUAL, NOTMEMBEROF, OR, PLUS, SQRT, SUBSTRING, UMINUS
 
Constructor Summary
IsEmpty()
           
IsEmpty(Expression e)
           
 
Method Summary
 void compileExpression()
          Checks the semantic integrity of an expression.
 boolean evaluate(java.lang.Object op)
           
 void evaluate(ParameterOperand[] pos, Tuple t)
          It evaluates the expression tree and puts the result into the operand result.
 java.lang.String getOperatorString()
          Returns the String representing the operator in Java
 
Methods inherited from class org.objectweb.medor.filter.lib.BasicUnaryOperator
clone, getExpression, getExpression, getOperandNumber, getResult, getType, isCompiled, setExpression, setExpression
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 
Methods inherited from interface org.objectweb.medor.filter.api.UnaryOperator
getExpression, setExpression
 
Methods inherited from interface org.objectweb.medor.filter.api.Operator
getExpression, getOperandNumber, setExpression
 
Methods inherited from interface org.objectweb.medor.filter.api.Expression
getResult, getType, isCompiled
 
Methods inherited from interface org.objectweb.medor.api.Cloneable
clone
 

Constructor Detail

IsEmpty

public IsEmpty()

IsEmpty

public IsEmpty(Expression e)
Method Detail

evaluate

public void evaluate(ParameterOperand[] pos,
                     Tuple t)
              throws MedorException,
                     java.lang.IllegalStateException
Description copied from interface: Expression
It evaluates the expression tree and puts the result into the operand result.

Specified by:
evaluate in interface Expression
Specified by:
evaluate in class BasicUnaryOperator
Parameters:
pos - a list of ParameterOperand
t - Tuple
Throws:
java.lang.IllegalStateException - if this expression is not compiled.
MedorException - if evaluation error

evaluate

public boolean evaluate(java.lang.Object op)

compileExpression

public void compileExpression()
                       throws TypingException,
                              MalformedExpressionException
Description copied from interface: Expression
Checks the semantic integrity of an expression. It checks that all types are compatible and prepare the expression to be evaluable.It also creates buffers where stores the result. Notes that when evaluating there is no creation of new objects. This method change the state of this expression object, it will be evaluable and not modifiable.

Specified by:
compileExpression in interface Expression
Throws:
MalformedExpressionException - if syntax error
TypingException - when incompatible types error occures.

getOperatorString

public java.lang.String getOperatorString()
Description copied from interface: Operator
Returns the String representing the operator in Java

Specified by:
getOperatorString in interface Operator
Returns:
the String representing the operator in Java