listFW.visitor
Class FoldL<T,P>

java.lang.Object
  listFW.visitor.FoldL<T,P>

All Implemented Interfaces:

IListAlgo<T,P,P>

public class FoldL<T,P>
extends java.lang.Object
implements IListAlgo<T,P,P>

Folds a list, starting at the left side.

Field Summary

private ILambda2<P,T,P>

_f

Constructor Summary

FoldL(ILambda2<P,T,P> f)
Constructor for a FoldL algorithm.

Method Summary

P	emptyCase(IMTList<? extends T> h, P... b) Empty case.
P	nonEmptyCase(INEList<? extends T> h, P... b) Non-empty case.

Methods inherited from class java.lang.Object

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

Field Detail

_f

private ILambda2<P,T,P> _f

Constructor Detail

FoldL

public FoldL(ILambda2<P,T,P> f)

Constructor for a FoldL algorithm.

Parameters:

f - a binary ILambda, i.e. one that takes two parameters as varargs.

Method Detail

emptyCase

public P emptyCase(IMTList<? extends T> h,
                   P... b)

Empty case. Return the initial value.

Specified by:

emptyCase in interface IListAlgo<T,P,P>

Parameters:

b - b[0] is the initial value.

Returns:

initial value

nonEmptyCase

public P nonEmptyCase(INEList<? extends T> h,
                      P... b)

Non-empty case. Apply lambda to initial value and first, and recur.

Specified by:

nonEmptyCase in interface IListAlgo<T,P,P>

Parameters:

b - b[0] is the initial value.

Returns:

result of folding