Implement .is_empty(), .len(), .iter() for ManagedMap.

This commit is contained in:
Astro 2018-03-06 06:26:29 +01:00 committed by whitequark
parent 4c9c688f3a
commit 660378c0bc
2 changed files with 131 additions and 2 deletions

View File

@ -18,4 +18,5 @@ mod map;
pub use object::Managed;
pub use slice::ManagedSlice;
#[cfg(feature = "map")]
pub use map::ManagedMap;
pub use map::{ManagedMap,
Iter as ManagedMapIter};

View File

@ -1,11 +1,16 @@
use core::mem;
use core::fmt;
use core::slice;
use core::borrow::Borrow;
#[cfg(feature = "std")]
use std::collections::BTreeMap;
#[cfg(feature = "std")]
use std::collections::btree_map::Iter as BTreeIter;
#[cfg(all(feature = "alloc", not(feature = "std")))]
use alloc::btree_map::BTreeMap;
#[cfg(all(feature = "alloc", not(feature = "std")))]
use alloc::btree_map::Iter as BTreeIter;
/// A managed map.
///
@ -194,6 +199,80 @@ impl<'a, K: Ord + 'a, V: 'a> ManagedMap<'a, K, V> {
&mut ManagedMap::Owned(ref mut map) => map.remove(key)
}
}
/// ManagedMap contains no elements?
pub fn is_empty(&self) -> bool {
match self {
&ManagedMap::Borrowed(ref pairs) =>
pairs.iter().all(|item| item.is_none()),
#[cfg(any(feature = "std", feature = "alloc"))]
&ManagedMap::Owned(ref map) =>
map.is_empty()
}
}
/// Returns the number of elements in the ManagedMap.
pub fn len(&self) -> usize {
match self {
&ManagedMap::Borrowed(ref pairs) =>
pairs.iter()
.take_while(|item| item.is_some())
.count(),
#[cfg(any(feature = "std", feature = "alloc"))]
&ManagedMap::Owned(ref map) =>
map.len()
}
}
pub fn iter(&'a self) -> Iter<'a, K, V> {
match self {
&ManagedMap::Borrowed(ref pairs) =>
Iter::Borrowed(pairs.iter()),
#[cfg(any(feature = "std", feature = "alloc"))]
&ManagedMap::Owned(ref map) =>
Iter::Owned(map.iter()),
}
}
}
pub enum Iter<'a, K: 'a, V: 'a> {
/// Borrowed variant.
Borrowed(slice::Iter<'a, Option<(K, V)>>),
/// Owned variant, only available with the `std` or `alloc` feature enabled.
#[cfg(any(feature = "std", feature = "alloc"))]
Owned(BTreeIter<'a, K, V>)
}
impl<'a, K: Ord + 'a, V: 'a> Iterator for Iter<'a, K, V> {
type Item = (&'a K, &'a V);
fn next(&mut self) -> Option<Self::Item> {
match self {
&mut Iter::Borrowed(ref mut iter) =>
match iter.next() {
Some(&Some((ref k, ref v))) => Some((&k, &v)),
Some(&None) => None,
None => None,
},
#[cfg(any(feature = "std", feature = "alloc"))]
&mut Iter::Owned(ref mut iter) =>
iter.next(),
}
}
fn size_hint(&self) -> (usize, Option<usize>) {
match self {
&Iter::Borrowed(ref iter) => {
let len = iter.clone()
.take_while(|item| item.is_some())
.count();
(len, Some(len))
},
#[cfg(any(feature = "std", feature = "alloc"))]
&Iter::Owned(ref iter) =>
iter.size_hint(),
}
}
}
// LCOV_EXCL_START
@ -225,6 +304,8 @@ mod test {
let mut pairs = all_pairs_full();
let mut map = ManagedMap::Borrowed(&mut pairs);
map.clear();
assert!(map.is_empty());
assert_eq!(map.len(), 0);
assert_eq!(unwrap(&map), all_pairs_empty());
}
@ -232,6 +313,7 @@ mod test {
fn test_get_some() {
let mut pairs = all_pairs_full();
let map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.len(), 4);
assert_eq!(map.get("a"), Some(&1));
assert_eq!(map.get("b"), Some(&2));
assert_eq!(map.get("c"), Some(&3));
@ -242,6 +324,8 @@ mod test {
fn test_get_none() {
let mut pairs = one_pair_full();
let map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.len(), 1);
assert!(!map.is_empty());
assert_eq!(map.get("q"), None);
}
@ -249,6 +333,8 @@ mod test {
fn test_get_mut_some() {
let mut pairs = all_pairs_full();
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.len(), 4);
assert!(!map.is_empty());
assert_eq!(map.get_mut("a"), Some(&mut 1));
assert_eq!(map.get_mut("b"), Some(&mut 2));
assert_eq!(map.get_mut("c"), Some(&mut 3));
@ -266,7 +352,12 @@ mod test {
fn test_insert_empty() {
let mut pairs = all_pairs_empty();
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.len(), 0);
assert!(map.is_empty());
assert_eq!(map.insert("a", 1), Ok(None));
assert_eq!(map.len(), 1);
assert!(!map.is_empty());
assert_eq!(unwrap(&map), [Some(("a", 1)), None, None, None]);
}
@ -276,6 +367,8 @@ mod test {
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.insert("a", 1), Ok(None));
assert_eq!(map.insert("a", 2), Ok(Some(1)));
assert_eq!(map.len(), 1);
assert!(!map.is_empty());
assert_eq!(unwrap(&map), [Some(("a", 2)), None, None, None]);
}
@ -284,6 +377,7 @@ mod test {
let mut pairs = all_pairs_full();
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.insert("q", 1), Err(("q", 1)));
assert_eq!(map.len(), 4);
assert_eq!(unwrap(&map), all_pairs_full());
}
@ -309,6 +403,7 @@ mod test {
let mut pairs = one_pair_full();
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.remove("b"), None);
assert_eq!(map.len(), 1);
}
#[test]
@ -316,7 +411,40 @@ mod test {
let mut pairs = all_pairs_full();
let mut map = ManagedMap::Borrowed(&mut pairs);
assert_eq!(map.remove("a"), Some(1));
assert_eq!(map.len(), 3);
assert_eq!(unwrap(&map), [Some(("b", 2)), Some(("c", 3)), Some(("d", 4)), None]);
}
}
#[test]
fn test_iter_none() {
let mut pairs = all_pairs_empty();
let map = ManagedMap::Borrowed(&mut pairs);
let mut iter = map.iter();
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
}
#[test]
fn test_iter_one() {
let mut pairs = one_pair_full();
let map = ManagedMap::Borrowed(&mut pairs);
let mut iter = map.iter();
assert_eq!(iter.size_hint(), (1, Some(1)));
assert_eq!(iter.next(), Some((&"a", &1)));
assert_eq!(iter.size_hint(), (0, Some(0)));
assert_eq!(iter.next(), None);
}
#[test]
fn test_iter_full() {
let mut pairs = all_pairs_full();
let map = ManagedMap::Borrowed(&mut pairs);
let mut iter = map.iter();
assert_eq!(iter.size_hint(), (4, Some(4)));
assert_eq!(iter.next(), Some((&"a", &1)));
assert_eq!(iter.next(), Some((&"b", &2)));
assert_eq!(iter.next(), Some((&"c", &3)));
assert_eq!(iter.next(), Some((&"d", &4)));
assert_eq!(iter.next(), None);
}
}