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Stabilize iter::successors and iter::from_fn #58576

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Merged
merged 2 commits into from
Feb 20, 2019
Merged

Stabilize iter::successors and iter::from_fn #58576

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95d2795
Stabilize iter::successors
SimonSapin Feb 19, 2019
3906cb9
Stabilize iter::from_fn
SimonSapin Feb 19, 2019
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6 changes: 4 additions & 2 deletions src/libcore/iter/mod.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -326,8 +326,10 @@ pub use self::sources::{Empty, empty};
pub use self::sources::{Once, once};
#[unstable(feature = "iter_once_with", issue = "57581")]
pub use self::sources::{OnceWith, once_with};
#[unstable(feature = "iter_unfold", issue = "55977")]
pub use self::sources::{FromFn, from_fn, Successors, successors};
#[stable(feature = "iter_from_fn", since = "1.34.0")]
pub use self::sources::{FromFn, from_fn};
#[stable(feature = "iter_successors", since = "1.34.0")]
pub use self::sources::{Successors, successors};

#[stable(feature = "rust1", since = "1.0.0")]
pub use self::traits::{FromIterator, IntoIterator, DoubleEndedIterator, Extend};
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20 changes: 9 additions & 11 deletions src/libcore/iter/sources.rs
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Expand Up @@ -514,7 +514,6 @@ pub fn once_with<A, F: FnOnce() -> A>(gen: F) -> OnceWith<F> {
/// [module-level documentation]: index.html
///
/// ```
/// #![feature(iter_unfold)]
/// let mut count = 0;
/// let counter = std::iter::from_fn(move || {
/// // Increment our count. This is why we started at zero.
Expand All @@ -530,7 +529,7 @@ pub fn once_with<A, F: FnOnce() -> A>(gen: F) -> OnceWith<F> {
/// assert_eq!(counter.collect::<Vec<_>>(), &[1, 2, 3, 4, 5]);
/// ```
#[inline]
#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_from_fn", since = "1.34.0")]
pub fn from_fn<T, F>(f: F) -> FromFn<F>
where F: FnMut() -> Option<T>
{
Expand All @@ -544,10 +543,10 @@ pub fn from_fn<T, F>(f: F) -> FromFn<F>
///
/// [`iter::from_fn`]: fn.from_fn.html
#[derive(Clone)]
#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_from_fn", since = "1.34.0")]
pub struct FromFn<F>(F);

#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_from_fn", since = "1.34.0")]
impl<T, F> Iterator for FromFn<F>
where F: FnMut() -> Option<T>
{
Expand All @@ -559,7 +558,7 @@ impl<T, F> Iterator for FromFn<F>
}
}

#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_from_fn", since = "1.34.0")]
impl<F> fmt::Debug for FromFn<F> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("FromFn").finish()
Expand All @@ -572,13 +571,12 @@ impl<F> fmt::Debug for FromFn<F> {
/// and calls the given `FnMut(&T) -> Option<T>` closure to compute each item’s successor.
///
/// ```
/// #![feature(iter_unfold)]
/// use std::iter::successors;
///
/// let powers_of_10 = successors(Some(1_u16), |n| n.checked_mul(10));
/// assert_eq!(powers_of_10.collect::<Vec<_>>(), &[1, 10, 100, 1_000, 10_000]);
/// ```
#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_successors", since = "1.34.0")]
pub fn successors<T, F>(first: Option<T>, succ: F) -> Successors<T, F>
where F: FnMut(&T) -> Option<T>
{
Expand All @@ -598,13 +596,13 @@ pub fn successors<T, F>(first: Option<T>, succ: F) -> Successors<T, F>
///
/// [`successors`]: fn.successors.html
#[derive(Clone)]
#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_successors", since = "1.34.0")]
pub struct Successors<T, F> {
next: Option<T>,
succ: F,
}

#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_successors", since = "1.34.0")]
impl<T, F> Iterator for Successors<T, F>
where F: FnMut(&T) -> Option<T>
{
Expand All @@ -628,12 +626,12 @@ impl<T, F> Iterator for Successors<T, F>
}
}

#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_successors", since = "1.34.0")]
impl<T, F> FusedIterator for Successors<T, F>
where F: FnMut(&T) -> Option<T>
{}

#[unstable(feature = "iter_unfold", issue = "55977")]
#[stable(feature = "iter_successors", since = "1.34.0")]
impl<T: fmt::Debug, F> fmt::Debug for Successors<T, F> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_struct("Successors")
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1 change: 0 additions & 1 deletion src/libcore/tests/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,6 @@
#![feature(iter_copied)]
#![feature(iter_nth_back)]
#![feature(iter_once_with)]
#![feature(iter_unfold)]
#![feature(pattern)]
#![feature(range_is_empty)]
#![feature(raw)]
Expand Down