47 lines
940 B
Rust
47 lines
940 B
Rust
use std::iter::Peekable;
|
|
use std::ops::Deref;
|
|
|
|
pub struct Delimited<I: Iterator> {
|
|
is_first: bool,
|
|
iter: Peekable<I>,
|
|
}
|
|
|
|
pub trait IterDelimited: Iterator + Sized {
|
|
fn delimited(self) -> Delimited<Self> {
|
|
Delimited {
|
|
is_first: true,
|
|
iter: self.peekable(),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl<I: Iterator> IterDelimited for I {}
|
|
|
|
pub struct IteratorItem<T> {
|
|
value: T,
|
|
pub is_first: bool,
|
|
pub is_last: bool,
|
|
}
|
|
|
|
impl<I: Iterator> Iterator for Delimited<I> {
|
|
type Item = IteratorItem<I::Item>;
|
|
|
|
fn next(&mut self) -> Option<Self::Item> {
|
|
let item = IteratorItem {
|
|
value: self.iter.next()?,
|
|
is_first: self.is_first,
|
|
is_last: self.iter.peek().is_none(),
|
|
};
|
|
self.is_first = false;
|
|
Some(item)
|
|
}
|
|
}
|
|
|
|
impl<T> Deref for IteratorItem<T> {
|
|
type Target = T;
|
|
|
|
fn deref(&self) -> &Self::Target {
|
|
&self.value
|
|
}
|
|
}
|