net.sf.jec
Class Operator

java.lang.Object
  net.sf.jec.Operator

Direct Known Subclasses:

ArithmeticOperator, AssignOperator, BooleanOperator, ConstantOperator, GroupOperator, InvertibleOperator, MethodOperator, SelectOperator, TableOperator

public abstract class Operator

extends java.lang.Object

Abstract class parent of every operator. An operator might nest another operator, resulting in a function composition: OP1(x), OP2(OP1(x))

Thus, applying OP2 to an object 'x', implies appliying OP1 to 'x' and then OP2 to the result.

Author:

mballesteros

Field Summary

protected Operator[]	argOps
protected Operator	nestedOp Nested operator
static boolean	showFunctionString

Constructor Summary

Operator()
Creates a new operator that nest another operator

Operator(Operator nestedOp)
Creates a new operator that nest another operator

Method Summary

java.lang.Object	apply(java.lang.Object rootCtx, java.lang.Object ctx)
protected abstract java.lang.Object	directMap(java.lang.Object rootCtx, java.lang.Object ctx) Returns the associated value to the given context and root context
void	setArgumentOperators(Operator[] argOps)
void	setNestedOperator(Operator nestedOp) Sets the operator's nested operator
abstract java.lang.String	toExpressionString() Returns an expression String representation for this operator
abstract java.lang.String	toFunctionString() Returns a function representation String for this operator
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

showFunctionString

public static boolean showFunctionString

nestedOp

protected Operator nestedOp

Nested operator

argOps

protected Operator[] argOps

Constructor Detail

Operator

public Operator()

Creates a new operator that nest another operator

Operator

public Operator(Operator nestedOp)

Creates a new operator that nest another operator

Method Detail

setNestedOperator

public void setNestedOperator(Operator nestedOp)

Sets the operator's nested operator

setArgumentOperators

public void setArgumentOperators(Operator[] argOps)

toString

public java.lang.String toString()

toFunctionString

public abstract java.lang.String toFunctionString()

Returns a function representation String for this operator

toExpressionString

public abstract java.lang.String toExpressionString()

Returns an expression String representation for this operator

apply

public final java.lang.Object apply(java.lang.Object rootCtx,
                                    java.lang.Object ctx)
                             throws EvaluationException

Throws:

EvaluationException

directMap

protected abstract java.lang.Object directMap(java.lang.Object rootCtx,
                                              java.lang.Object ctx)
                                       throws EvaluationException

Returns the associated value to the given context and root context

Parameters:

rootCtx - The root context, needed for operators that require expression evaluation from root point. Example: Indexer operators

ctx - The current context where the operator will work over

Throws:

EvaluationException