public static A FoldLeft <A, B>(Func <A, B, A> f, A accum, IHeadTailList <B> list)
{
if (list.IsEmpty())
{
return(accum);
}
return(FoldLeft(f, f(accum, list.Head()), list.Tail()));
}
public static A FoldRight <A, B>(Func <B, A, A> f, A seed, IHeadTailList <B> list)
{
if (list.IsEmpty())
{
return(seed);
}
return(f(list.Head(), FoldRight(f, seed, list.Tail())));
}