Skip to content

Improved the use of Extend in a few Iterator methods #65219

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 7 commits into from
Closed

Improved the use of Extend in a few Iterator methods #65219

Changes from 1 commit
Commits
Show all changes
7 commits
Select commit Hold shift + click to select a range
9c7fe03
Improved the use of `Extend` in a few `Iterator` methods
Lucretiel Oct 8, 2019
dce6734
Switched to local functions away from closures, per #62429
Lucretiel Oct 8, 2019
1e9b187
Updated `unzip` to fully consume the provided iterator
Lucretiel Oct 9, 2019
c42d974
Added fuse & size_hint test to unzip
Lucretiel Oct 9, 2019
44fb4e9
Additional small changes
Lucretiel Oct 10, 2019
bf3a2b1
Removed broked try_fold impl from &mut Iterator
Lucretiel Oct 10, 2019
6357ec4
Added fusion and right.extend to partition.
Lucretiel Oct 10, 2019
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
49 changes: 18 additions & 31 deletions src/libcore/iter/traits/iterator.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1504,30 +1504,23 @@ pub trait Iterator {
/// assert_eq!(odd, vec![1, 3]);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
fn partition<B, F>(self, f: F) -> (B, B) where
fn partition<B, F>(self, mut predicate: F) -> (B, B) where
Self: Sized,
B: Default + Extend<Self::Item>,
F: FnMut(&Self::Item) -> bool
{
#[inline]
fn extend<'a, T, B: Extend<T>>(
mut f: impl FnMut(&T) -> bool + 'a,
left: &'a mut B,
right: &'a mut B,
) -> impl FnMut(T) + 'a {
move |x| {
if f(&x) {
left.extend(Some(x));
} else {
right.extend(Some(x));
}
}
}

let mut left: B = Default::default();
let mut right: B = Default::default();
let right_ref = &mut right;

self.for_each(extend(f, &mut left, &mut right));
left.extend(self.filter_map(#[inline] move |item| {
if predicate(&item) {
Some(item)
} else {
right_ref.extend(Some(item));
None
}
}));

(left, right)
}
Expand Down Expand Up @@ -2378,22 +2371,16 @@ pub trait Iterator {
FromB: Default + Extend<B>,
Self: Sized + Iterator<Item=(A, B)>,
{
fn extend<'a, A, B>(
ts: &'a mut impl Extend<A>,
us: &'a mut impl Extend<B>,
) -> impl FnMut((A, B)) + 'a {
move |(t, u)| {
ts.extend(Some(t));
us.extend(Some(u));
}
}

let mut ts: FromA = Default::default();
let mut us: FromB = Default::default();
let mut lhs = FromA::default();
let mut rhs = FromB::default();
let rhs_ref = &mut rhs;

self.for_each(extend(&mut ts, &mut us));
lhs.extend(self.map(#[inline] move |(a, b)| {
rhs_ref.extend(Some(b));
a
}));

(ts, us)
(lhs, rhs)
}

/// Creates an iterator which copies all of its elements.
Expand Down