cheep-crator-2/vendor/os_str_bytes/src/iter.rs

114 lines
2.5 KiB
Rust

//! Iterators provided by this crate.
#![cfg_attr(os_str_bytes_docs_rs, doc(cfg(feature = "raw_os_str")))]
use std::fmt;
use std::fmt::Debug;
use std::fmt::Formatter;
use std::iter::FusedIterator;
use std::str;
use super::pattern::Encoded;
use super::Pattern;
use super::RawOsStr;
// [memchr::memmem::FindIter] is not currently used, since this struct would
// become self-referential. Additionally, that iterator does not implement
// [DoubleEndedIterator], and its implementation would likely require
// significant changes to implement that trait.
/// The iterator returned by [`RawOsStr::split`].
pub struct Split<'a, P>
where
P: Pattern,
{
string: Option<&'a RawOsStr>,
pat: P::__Encoded,
}
impl<'a, P> Split<'a, P>
where
P: Pattern,
{
pub(super) fn new(string: &'a RawOsStr, pat: P) -> Self {
let pat = pat.__encode();
assert!(
!pat.__get().is_empty(),
"cannot split using an empty pattern",
);
Self {
string: Some(string),
pat,
}
}
}
macro_rules! impl_next {
( $self:ident , $split_method:ident , $swap_fn:expr ) => {{
$self
.string?
.$split_method(&$self.pat)
.map(|substrings| {
let (substring, string) = $swap_fn(substrings);
$self.string = Some(string);
substring
})
.or_else(|| $self.string.take())
}};
}
impl<P> DoubleEndedIterator for Split<'_, P>
where
P: Pattern,
{
fn next_back(&mut self) -> Option<Self::Item> {
impl_next!(self, rsplit_once_raw, |(prefix, suffix)| (suffix, prefix))
}
}
impl<'a, P> Iterator for Split<'a, P>
where
P: Pattern,
{
type Item = &'a RawOsStr;
#[inline]
fn last(mut self) -> Option<Self::Item> {
self.next_back()
}
fn next(&mut self) -> Option<Self::Item> {
impl_next!(self, split_once_raw, |x| x)
}
}
impl<P> Clone for Split<'_, P>
where
P: Pattern,
{
#[inline]
fn clone(&self) -> Self {
Self {
string: self.string,
pat: self.pat.clone(),
}
}
}
impl<P> Debug for Split<'_, P>
where
P: Pattern,
{
#[inline]
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
f.debug_struct("Split")
.field("string", &self.string)
.field(
"pat",
&str::from_utf8(self.pat.__get()).expect("invalid pattern"),
)
.finish()
}
}
impl<P> FusedIterator for Split<'_, P> where P: Pattern {}