public Iteratee <D, A> ContraSelect <D>(Func <D, E> f)
{
return(Fold(
(a, i) => Iteratee <D, A> .Done(a, i.IsEof ? Input <D> .Eof() : Input <D> .Empty())
, r => Iteratee <D, A> .Cont(i => r(i.Select(f)).ContraSelect(f))
));
}
public static Iteratee <E, B> SelectMany <E, A, B>(this Iteratee <E, A> k, Func <A, Iteratee <E, B> > f) =>
k.Fold(
(a, i) => i.IsEmpty ?
f(a) :
f(a).Fold(
(b, _) => Iteratee <E, B> .Done(b, i)
, s => s(i)
)
, r => Iteratee <E, B> .Cont(u => r(u).SelectMany(f))
);
public Iteratee <E, A> Done <A>(A a)
{
return(Iteratee <E, A> .Done(a, this));
}
public static Iteratee <E, B> Select <E, A, B>(this Iteratee <E, A> k, Func <A, B> f)
{
return(k.SelectMany <E, A, B>(a => Iteratee <E, B> .Done(f(a), Input <E> .Empty())));
}
public Iteratee <E, A> Done <A>(A a) => Iteratee <E, A> .Done(a, this);
