use crate::infallible::XapEnumByInput;
use crate::infallible::fun::Map;
use crate::infallible::fun::MapEnum;
use crate::infallible::xap::Xap;
use crate::sizes::Many;
use core::iter::FusedIterator;
pub struct ManyM<X: Xap<Size = Many>, G: Map<I = X::O>> {
x: X,
g: G,
}
impl<X: Xap<Size = Many>, G: Map<I = X::O>> Clone for ManyM<X, G> {
fn clone(&self) -> Self {
*self
}
}
impl<X: Xap<Size = Many>, G: Map<I = X::O>> Copy for ManyM<X, G> {}
impl<X: Xap<Size = Many>, G: Map<I = X::O>> ManyM<X, G> {
pub fn new(x: X, g: G) -> Self {
Self { x, g }
}
}
impl<X: XapEnumByInput<Size = Many>, G: Map<I = X::O>> XapEnumByInput for ManyM<X, G> {
type Enumerated = ManyM<X::Enumerated, MapEnum<G>>;
fn enumerate(self) -> Self::Enumerated {
let g = MapEnum::new(self.g);
let x = self.x.enumerate();
ManyM::new(x, g)
}
}
impl<X: Xap<Size = Many>, G: Map<I = X::O>> Xap for ManyM<X, G> {
type I = X::I;
type O = G::O;
type Size = Many;
type Values = IterManyM<<X::Values as IntoIterator>::IntoIter, G>;
#[inline(always)]
fn xap(&self, i: Self::I) -> Self::Values {
let i = self.x.xap(i).into_iter();
IterManyM { i, g: self.g }
}
}
pub struct IterManyM<I, G>
where
I: Iterator,
G: Map<I = I::Item>,
{
i: I,
g: G,
}
impl<I, G> Iterator for IterManyM<I, G>
where
I: Iterator,
G: Map<I = I::Item>,
{
type Item = G::O;
#[inline(always)]
fn next(&mut self) -> Option<Self::Item> {
self.i.next().map(|x| self.g.map(x))
}
#[inline(always)]
fn size_hint(&self) -> (usize, Option<usize>) {
self.i.size_hint()
}
#[inline]
fn fold<B, F>(self, init: B, f: F) -> B
where
Self: Sized,
F: FnMut(B, Self::Item) -> B,
{
self.i.map(|x| self.g.map(x)).fold(init, f)
}
#[inline]
fn count(self) -> usize
where
Self: Sized,
{
self.i.count()
}
}
impl<I, G> ExactSizeIterator for IterManyM<I, G>
where
I: ExactSizeIterator,
G: Map<I = I::Item>,
{
#[inline(always)]
fn len(&self) -> usize {
self.i.len()
}
}
impl<I, G> FusedIterator for IterManyM<I, G>
where
I: FusedIterator,
G: Map<I = I::Item>,
{
}
impl<I, G> DoubleEndedIterator for IterManyM<I, G>
where
I: DoubleEndedIterator,
G: Map<I = I::Item>,
{
fn next_back(&mut self) -> Option<Self::Item> {
self.i.next_back().map(|x| self.g.map(x))
}
}