jlibs.xml.sax.dog.expr.func

Class PeekingFunction

java.lang.Object

jlibs.xml.sax.dog.expr.func.Function

jlibs.xml.sax.dog.expr.func.PeekingFunction

public abstract class PeekingFunction
extends Function

PeekingFunction is a function which can evaluate its results before all its arguments are known. Note that such prediction might be possible only in some cases. For example: Any arthimetic operation whose one operand is infinity always returns infinity

Author:

Santhosh Kumar T

Field Summary

Fields inherited from class jlibs.xml.sax.dog.expr.func.Function

mandatory, memberTypes, name, namespace, resultType, varArgs

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PeekingFunction(String name, DataType resultType, boolean varArgs, DataType... memberTypes)
protected	PeekingFunction(String name, DataType resultType, boolean varArgs, int mandatory, DataType... memberTypes)

Method Summary

Modifier and Type	Method and Description
protected abstract Object	onMemberResult(int index, Object result) After each member result is evaluated, this method is called.

Methods inherited from class jlibs.xml.sax.dog.expr.func.Function

canAccept, evaluate, isOperator, memberType

Methods inherited from class java.lang.Object

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

Constructor Detail

PeekingFunction

protected PeekingFunction(String name,
                          DataType resultType,
                          boolean varArgs,
                          DataType... memberTypes)

PeekingFunction

protected PeekingFunction(String name,
                          DataType resultType,
                          boolean varArgs,
                          int mandatory,
                          DataType... memberTypes)

Method Detail

onMemberResult

protected abstract Object onMemberResult(int index,
                                         Object result)

After each member result is evaluated, this method is called. Returns result(non-null), if the function can be evaluated.