use std::iter::{Fuse, FusedIterator};
use crate::*;
use crate::iter::*;
pub trait TimeComplementary: TimeConvexIterator {
type Output:TimeConvexIterator<TimePoint=Self::TimePoint>;
fn complementary(self) -> Self::Output;
}
impl<TW> TimeComplementary for TW
where
TW: TimeConvexIterator
{
type Output = IterComplementary<Self>;
#[inline]
fn complementary(self) -> Self::Output {
IterComplementary::new(self)
}
}
pub struct IterComplementary<I:TimeConvexIterator>
{
iter: Fuse<I>,
lower: I::TimePoint
}
impl<I:TimeConvexIterator> IterComplementary<I>
{
fn new(iter: I) -> Self {
Self {
iter: iter.fuse(),
lower: -I::TimePoint::INFINITE
}
}
}
impl<I:TimeConvexIterator> TimeConvexIterator for IterComplementary<I> {
type TimePoint = I::TimePoint;
}
impl<I:TimeConvexIterator> FusedIterator for IterComplementary<I> { }
impl<I:TimeConvexIterator> Iterator for IterComplementary<I>
{
type Item = TimeInterval<I::TimePoint>;
fn next(&mut self) -> Option<Self::Item>
{
if self.lower.is_past_infinite() {
let start = self.iter.next()
.and_then(|next| {
let upper = next.lower_bound().just_before();
self.lower = next.upper_bound().just_after();
if upper == -I::TimePoint::INFINITE {
None
} else {
Some(TimeInterval { lower: -I::TimePoint::INFINITE, upper})
}
});
if start.is_some() { return start; }
}
for next in self.iter.by_ref()
{
if self.lower < next.lower_bound() {
let result = TimeInterval {
lower: self.lower,
upper: next.lower_bound().just_before()
};
self.lower = next.upper_bound().just_after();
return Some(result);
}
}
if self.lower.is_future_infinite() {
None
} else {
let result = TimeInterval {
lower: self.lower,
upper: I::TimePoint::INFINITE
};
self.lower = I::TimePoint::INFINITE;
Some(result)
}
}
fn size_hint(&self) -> (usize, Option<usize>)
{
let (min,max) = self.iter.size_hint();
if self.lower.is_finite() {
(min.saturating_sub(1), max)
} else {
(min.saturating_sub(1), max.map(|i| i + 1))
}
}
}