Skip to content
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

DO NOT MERGE: experimental implementation of Entry API RFC #37143

Closed
wants to merge 3 commits into from
Closed

DO NOT MERGE: experimental implementation of Entry API RFC #37143

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
7d71650
DO NOT MERGE: implementation of RFC 1769
cristicbz Oct 13, 2016
aa418d2
hacky fix to type inference issues in map entry docs
cristicbz Oct 13, 2016
ca81efb
update with crater knowledge:
cristicbz Oct 14, 2016
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
27 changes: 27 additions & 0 deletions src/libcollections/borrow.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -69,6 +69,33 @@ impl<T> ToOwned for T where T: Clone {
}
}

#[unstable(feature = "entry_into_owned", issue = "1")]
pub trait AsBorrowOf<T, B: ?Sized>: Sized where T: Borrow<B> {
#[unstable(feature = "entry_into_owned", issue = "1")]
fn into_owned(self) -> T;

#[unstable(feature = "entry_into_owned", issue = "1")]
fn as_borrow_of(&self) -> &B;
}

#[unstable(feature = "entry_into_owned", issue = "1")]
impl<T> AsBorrowOf<T, T> for T {
default fn into_owned(self) -> T { self }
default fn as_borrow_of(&self) -> &Self { self }
}

#[unstable(feature = "entry_into_owned", issue = "1")]
impl<'a, T: Deref> AsBorrowOf<&'a T::Target, T::Target> for &'a T {
default fn into_owned(self) -> &'a T::Target { self.deref() }
default fn as_borrow_of(&self) -> &T::Target { self.deref() }
}

#[unstable(feature = "entry_into_owned", issue = "1")]
impl<'a, B: ToOwned + ?Sized> AsBorrowOf<B::Owned, B> for &'a B {
fn into_owned(self) -> B::Owned { self.to_owned() }
fn as_borrow_of(&self) -> &B { *self }
}

/// A clone-on-write smart pointer.
///
/// The type `Cow` is a smart pointer providing clone-on-write functionality: it
Expand Down
56 changes: 41 additions & 15 deletions src/libcollections/btree/map.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ use core::marker::PhantomData;
use core::ops::Index;
use core::{fmt, intrinsics, mem, ptr};

use borrow::Borrow;
use borrow::{Borrow, AsBorrowOf};
use Bound::{self, Excluded, Included, Unbounded};

use super::node::{self, Handle, NodeRef, marker};
Expand Down Expand Up @@ -112,6 +112,7 @@ use self::Entry::*;
/// // type inference lets us omit an explicit type signature (which
/// // would be `BTreeMap<&str, u8>` in this example).
/// let mut player_stats = BTreeMap::new();
/// # {let __help_inference_out: &BTreeMap<&_, _> = &player_stats;}
///
/// fn random_stat_buff() -> u8 {
/// // could actually return some random value here - let's just return
Expand Down Expand Up @@ -219,7 +220,7 @@ impl<K: Clone, V: Clone> Clone for BTreeMap<K, V> {
}

impl<K, Q: ?Sized> super::Recover<Q> for BTreeMap<K, ()>
where K: Borrow<Q> + Ord,
where K: Borrow<Q> + Borrow<K> + Ord,
Q: Ord
{
type Key = K;
Expand Down Expand Up @@ -324,11 +325,11 @@ pub struct RangeMut<'a, K: 'a, V: 'a> {
/// [`BTreeMap`]: struct.BTreeMap.html
/// [`entry`]: struct.BTreeMap.html#method.entry
#[stable(feature = "rust1", since = "1.0.0")]
pub enum Entry<'a, K: 'a, V: 'a> {
pub enum Entry<'a, K: 'a, V: 'a, Q: 'a = K, B: 'a + ?Sized = K> {
/// A vacant Entry
#[stable(feature = "rust1", since = "1.0.0")]
Vacant(#[stable(feature = "rust1", since = "1.0.0")]
VacantEntry<'a, K, V>),
VacantEntry<'a, K, V, Q, B>),

/// An occupied Entry
#[stable(feature = "rust1", since = "1.0.0")]
Expand All @@ -337,7 +338,12 @@ pub enum Entry<'a, K: 'a, V: 'a> {
}

#[stable(feature= "debug_btree_map", since = "1.12.0")]
impl<'a, K: 'a + Debug + Ord, V: 'a + Debug> Debug for Entry<'a, K, V> {
impl<'a, K, V, Q, B: ?Sized> Debug for Entry<'a, K, V, Q, B>
where K: 'a + Debug + Ord,
V: 'a + Debug,
Q: 'a + Debug,
B: 'a
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Vacant(ref v) => f.debug_tuple("Entry")
Expand All @@ -354,20 +360,25 @@ impl<'a, K: 'a + Debug + Ord, V: 'a + Debug> Debug for Entry<'a, K, V> {
///
/// [`Entry`]: enum.Entry.html
#[stable(feature = "rust1", since = "1.0.0")]
pub struct VacantEntry<'a, K: 'a, V: 'a> {
key: K,
pub struct VacantEntry<'a, K: 'a, V: 'a, Q: 'a = K, B: 'a + ?Sized = K> {
key: Q,
handle: Handle<NodeRef<marker::Mut<'a>, K, V, marker::Leaf>, marker::Edge>,
length: &'a mut usize,

// Be invariant in `K` and `V`
_marker: PhantomData<&'a mut (K, V)>,
_marker: PhantomData<&'a mut (K, V, B)>,
}

#[stable(feature= "debug_btree_map", since = "1.12.0")]
impl<'a, K: 'a + Debug + Ord, V: 'a> Debug for VacantEntry<'a, K, V> {
impl<'a, K, V, Q, B: ?Sized> Debug for VacantEntry<'a, K, V, Q, B>
where K: 'a + Debug + Ord,
V: 'a,
Q: 'a + Debug,
B: 'a
{
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.debug_tuple("VacantEntry")
.field(self.key())
.field(&self.key)
.finish()
}
}
Expand Down Expand Up @@ -861,8 +872,12 @@ impl<K: Ord, V> BTreeMap<K, V> {
/// assert_eq!(count["a"], 3);
/// ```
#[stable(feature = "rust1", since = "1.0.0")]
pub fn entry(&mut self, key: K) -> Entry<K, V> {
match search::search_tree(self.root.as_mut(), &key) {
pub fn entry<Q, B: ?Sized>(&mut self, key: Q) -> Entry<K, V, Q, B>
where Q: AsBorrowOf<K, B>,
K: Borrow<B>,
B: Ord,
{
match search::search_tree(self.root.as_mut(), key.as_borrow_of()) {
Found(handle) => {
Occupied(OccupiedEntry {
handle: handle,
Expand Down Expand Up @@ -1960,7 +1975,10 @@ impl<K, V> BTreeMap<K, V> {
}
}

impl<'a, K: Ord, V> Entry<'a, K, V> {
impl<'a, K, V, Q, B: ?Sized> Entry<'a, K, V, Q, B>
where K: Ord + Borrow<B>,
Q: AsBorrowOf<K, B>
{
/// Ensures a value is in the entry by inserting the default if empty, and returns
/// a mutable reference to the value in the entry.
///
Expand Down Expand Up @@ -2004,7 +2022,9 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
Vacant(entry) => entry.insert(default()),
}
}
}

impl<'a, K: Ord, V, B: ?Sized> Entry<'a, K, V, K, B> {
/// Returns a reference to this entry's key.
///
/// # Examples
Expand All @@ -2024,7 +2044,7 @@ impl<'a, K: Ord, V> Entry<'a, K, V> {
}
}

impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
impl<'a, K: Ord, V, B: ?Sized> VacantEntry<'a, K, V, K, B> {
/// Gets a reference to the key that would be used when inserting a value
/// through the VacantEntry.
///
Expand Down Expand Up @@ -2059,7 +2079,12 @@ impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
pub fn into_key(self) -> K {
self.key
}
}

impl<'a, K, V, Q, B: ?Sized> VacantEntry<'a, K, V, Q, B>
where K: Ord + Borrow<B>,
Q: AsBorrowOf<K, B>
{
/// Sets the value of the entry with the `VacantEntry`'s key,
/// and returns a mutable reference to it.
///
Expand All @@ -2082,12 +2107,13 @@ impl<'a, K: Ord, V> VacantEntry<'a, K, V> {
*self.length += 1;

let out_ptr;
let key = AsBorrowOf::<K, B>::into_owned(self.key);

let mut ins_k;
let mut ins_v;
let mut ins_edge;

let mut cur_parent = match self.handle.insert(self.key, value) {
let mut cur_parent = match self.handle.insert(key, value) {
(Fit(handle), _) => return handle.into_kv_mut().1,
(Split(left, k, v, right), ptr) => {
ins_k = k;
Expand Down
Loading