ringbuf: Implement DoubleEndedIterator

This commit is contained in:
blake2-ppc 2013-07-16 01:13:26 +02:00
parent 9d7e01bb39
commit 3385e795c5

View File

@ -17,7 +17,7 @@ use std::num;
use std::util;
use std::uint;
use std::vec;
use std::iterator::FromIterator;
use std::iterator::{FromIterator, InvertIterator};
use container::Deque;
@ -180,29 +180,29 @@ impl<T> RingBuf<T> {
/// Front-to-back iterator.
pub fn iter<'a>(&'a self) -> RingBufIterator<'a, T> {
RingBufIterator{index: 0, nelts: self.nelts, elts: self.elts, lo: self.lo}
RingBufIterator{index: 0, rindex: self.nelts - 1,
nelts: self.nelts, elts: self.elts, lo: self.lo}
}
/// Back-to-front iterator.
pub fn rev_iter<'a>(&'a self) -> InvertIterator<&'a T, RingBufIterator<'a, T>> {
self.iter().invert()
}
/// Front-to-back iterator which returns mutable values.
pub fn mut_iter<'a>(&'a mut self) -> RingBufMutIterator<'a, T> {
RingBufMutIterator{index: 0, nelts: self.nelts, elts: self.elts, lo: self.lo}
}
/// Back-to-front iterator.
pub fn rev_iter<'a>(&'a self) -> RingBufRevIterator<'a, T> {
RingBufRevIterator{index: self.nelts-1, nelts: self.nelts, elts: self.elts,
lo: self.lo}
RingBufMutIterator{index: 0, rindex: self.nelts - 1,
nelts: self.nelts, elts: self.elts, lo: self.lo}
}
/// Back-to-front iterator which returns mutable values.
pub fn mut_rev_iter<'a>(&'a mut self) -> RingBufMutRevIterator<'a, T> {
RingBufMutRevIterator{index: self.nelts-1, nelts: self.nelts, elts: self.elts,
lo: self.lo}
pub fn mut_rev_iter<'a>(&'a mut self) -> InvertIterator<&'a mut T, RingBufMutIterator<'a, T>> {
self.mut_iter().invert()
}
}
macro_rules! iterator {
(impl $name:ident -> $elem:ty, $getter:ident, $step:expr) => {
(impl $name:ident -> $elem:ty, $getter:ident) => {
impl<'self, T> Iterator<$elem> for $name<'self, T> {
#[inline]
fn next(&mut self) -> Option<$elem> {
@ -210,7 +210,7 @@ macro_rules! iterator {
return None;
}
let raw_index = raw_index(self.lo, self.elts.len(), self.index);
self.index += $step;
self.index += 1;
self.nelts -= 1;
Some(self.elts[raw_index]. $getter ())
}
@ -223,41 +223,44 @@ macro_rules! iterator {
}
}
macro_rules! iterator_rev {
(impl $name:ident -> $elem:ty, $getter:ident) => {
impl<'self, T> DoubleEndedIterator<$elem> for $name<'self, T> {
#[inline]
fn next_back(&mut self) -> Option<$elem> {
if self.nelts == 0 {
return None;
}
let raw_index = raw_index(self.lo, self.elts.len(), self.rindex);
self.rindex -= 1;
self.nelts -= 1;
Some(self.elts[raw_index]. $getter ())
}
}
}
}
/// RingBuf iterator
pub struct RingBufIterator<'self, T> {
priv lo: uint,
priv nelts: uint,
priv index: uint,
priv rindex: uint,
priv elts: &'self [Option<T>],
}
iterator!{impl RingBufIterator -> &'self T, get_ref, 1}
/// RingBuf reverse iterator
pub struct RingBufRevIterator<'self, T> {
priv lo: uint,
priv nelts: uint,
priv index: uint,
priv elts: &'self [Option<T>],
}
iterator!{impl RingBufRevIterator -> &'self T, get_ref, -1}
iterator!{impl RingBufIterator -> &'self T, get_ref}
iterator_rev!{impl RingBufIterator -> &'self T, get_ref}
/// RingBuf mutable iterator
pub struct RingBufMutIterator<'self, T> {
priv lo: uint,
priv nelts: uint,
priv index: uint,
priv rindex: uint,
priv elts: &'self mut [Option<T>],
}
iterator!{impl RingBufMutIterator -> &'self mut T, get_mut_ref, 1}
/// RingBuf mutable reverse iterator
pub struct RingBufMutRevIterator<'self, T> {
priv lo: uint,
priv nelts: uint,
priv index: uint,
priv elts: &'self mut [Option<T>],
}
iterator!{impl RingBufMutRevIterator -> &'self mut T, get_mut_ref, -1}
iterator!{impl RingBufMutIterator -> &'self mut T, get_mut_ref}
iterator_rev!{impl RingBufMutIterator -> &'self mut T, get_mut_ref}
/// Grow is only called on full elts, so nelts is also len(elts), unlike
/// elsewhere.