cascading.operation.expression
Class ExpressionOperation

java.lang.Object
  cascading.operation.BaseOperation
      cascading.operation.expression.ExpressionOperation

All Implemented Interfaces:

Operation, Serializable

Direct Known Subclasses:

AssertExpression, ExpressionFilter, ExpressionFunction

public class ExpressionOperation
extends BaseOperation

Class ExpressionOperation is the base class for ExpressionFunction and ExpressionFilter.

See Also:

Serialized Form

Field Summary

protected String	expression Field expression
protected Class[]	parameterTypes Field parameterTypes

Fields inherited from class cascading.operation.BaseOperation

fieldDeclaration, numArgs

Fields inherited from interface cascading.operation.Operation

ANY

Constructor Summary

protected	ExpressionOperation(Fields fieldDeclaration, String expression, Class... parameterTypes)
protected	ExpressionOperation(String expression, Class... parameterTypes)

Method Summary

protected Comparable

evaluate(TupleEntry input) Performs the actual expression evaluation.

Methods inherited from class cascading.operation.BaseOperation

getFieldDeclaration, getNumArgs, printOperationInternal, toString, toStringInternal

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

expression

protected String expression

Field expression

parameterTypes

protected Class[] parameterTypes

Field parameterTypes

Constructor Detail

ExpressionOperation

protected ExpressionOperation(Fields fieldDeclaration,
                              String expression,
                              Class... parameterTypes)

ExpressionOperation

protected ExpressionOperation(String expression,
                              Class... parameterTypes)

Method Detail

evaluate

protected Comparable evaluate(TupleEntry input)

Performs the actual expression evaluation.

Parameters:

input - of type TupleEntry

Returns:

Comparable