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// This file is part of ICU4X. For terms of use, please see the file
// called LICENSE at the top level of the ICU4X source tree
use crate::store::*;
use alloc::borrow::Borrow;
use alloc::boxed::Box;
use alloc::vec::Vec;
use core::cmp::Ordering;
use core::iter::FromIterator;
use core::marker::PhantomData;
use core::mem;
use core::ops::{Index, IndexMut, Range};
/// A simple "flat" map based on a sorted vector
///
/// See the [module level documentation][super] for why one should use this.
///
/// The API is roughly similar to that of [`std::collections::BTreeMap`].
#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
#[cfg_attr(feature = "yoke", derive(yoke::Yokeable))]
pub struct LiteMap<K: ?Sized, V: ?Sized, S = alloc::vec::Vec<(K, V)>> {
pub(crate) values: S,
pub(crate) _key_type: PhantomData<K>,
pub(crate) _value_type: PhantomData<V>,
}
impl<K, V> LiteMap<K, V> {
/// Construct a new [`LiteMap`] backed by Vec
pub const fn new_vec() -> Self {
Self {
values: alloc::vec::Vec::new(),
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K, V, S> LiteMap<K, V, S> {
/// Construct a new [`LiteMap`] using the given values
///
/// The store must be sorted and have no duplicate keys.
pub const fn from_sorted_store_unchecked(values: S) -> Self {
Self {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K, V> LiteMap<K, V, Vec<(K, V)>> {
/// Convert a [`LiteMap`] into a sorted `Vec<(K, V)>`.
#[inline]
pub fn into_tuple_vec(self) -> Vec<(K, V)> {
self.values
}
}
impl<K: ?Sized, V: ?Sized, S> LiteMap<K, V, S>
where
S: StoreConstEmpty<K, V>,
{
/// Create a new empty [`LiteMap`]
pub const fn new() -> Self {
Self {
values: S::EMPTY,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K: ?Sized, V: ?Sized, S> LiteMap<K, V, S>
where
S: Store<K, V>,
{
/// The number of elements in the [`LiteMap`]
pub fn len(&self) -> usize {
self.values.lm_len()
}
/// Whether the [`LiteMap`] is empty
pub fn is_empty(&self) -> bool {
self.values.lm_is_empty()
}
/// Get the key-value pair residing at a particular index
///
/// In most cases, prefer [`LiteMap::get()`] over this method.
#[inline]
pub fn get_indexed(&self, index: usize) -> Option<(&K, &V)> {
self.values.lm_get(index)
}
/// Get the lowest-rank key/value pair from the `LiteMap`, if it exists.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map =
/// LiteMap::<i32, &str, Vec<_>>::from_iter([(1, "uno"), (3, "tres")]);
///
/// assert_eq!(map.first(), Some((&1, &"uno")));
/// ```
#[inline]
pub fn first(&self) -> Option<(&K, &V)> {
self.values.lm_get(0)
}
/// Get the highest-rank key/value pair from the `LiteMap`, if it exists.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map =
/// LiteMap::<i32, &str, Vec<_>>::from_iter([(1, "uno"), (3, "tres")]);
///
/// assert_eq!(map.last(), Some((&3, &"tres")));
/// ```
#[inline]
pub fn last(&self) -> Option<(&K, &V)> {
self.values.lm_get(self.len() - 1)
}
/// Returns a new [`LiteMap`] with owned keys and values.
///
/// The trait bounds allow transforming most slice and string types.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<&str, &str> = LiteMap::new_vec();
/// map.insert("one", "uno");
/// map.insert("two", "dos");
///
/// let boxed_map: LiteMap<Box<str>, Box<str>> = map.to_boxed_keys_values();
///
/// assert_eq!(boxed_map.get("one"), Some(&Box::from("uno")));
/// ```
pub fn to_boxed_keys_values<KB: ?Sized, VB: ?Sized, SB>(&self) -> LiteMap<Box<KB>, Box<VB>, SB>
where
SB: StoreMut<Box<KB>, Box<VB>>,
K: Borrow<KB>,
V: Borrow<VB>,
Box<KB>: for<'a> From<&'a KB>,
Box<VB>: for<'a> From<&'a VB>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(Box::from(k.borrow()), Box::from(v.borrow()))
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Returns a new [`LiteMap`] with owned keys and cloned values.
///
/// The trait bounds allow transforming most slice and string types.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<&str, usize> = LiteMap::new_vec();
/// map.insert("one", 11);
/// map.insert("two", 22);
///
/// let boxed_map: LiteMap<Box<str>, usize> = map.to_boxed_keys();
///
/// assert_eq!(boxed_map.get("one"), Some(&11));
/// ```
pub fn to_boxed_keys<KB: ?Sized, SB>(&self) -> LiteMap<Box<KB>, V, SB>
where
V: Clone,
SB: StoreMut<Box<KB>, V>,
K: Borrow<KB>,
Box<KB>: for<'a> From<&'a KB>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(Box::from(k.borrow()), v.clone())
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Returns a new [`LiteMap`] with cloned keys and owned values.
///
/// The trait bounds allow transforming most slice and string types.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<usize, &str> = LiteMap::new_vec();
/// map.insert(11, "uno");
/// map.insert(22, "dos");
///
/// let boxed_map: LiteMap<usize, Box<str>> = map.to_boxed_values();
///
/// assert_eq!(boxed_map.get(&11), Some(&Box::from("uno")));
/// ```
pub fn to_boxed_values<VB: ?Sized, SB>(&self) -> LiteMap<K, Box<VB>, SB>
where
K: Clone,
SB: StoreMut<K, Box<VB>>,
V: Borrow<VB>,
Box<VB>: for<'a> From<&'a VB>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(k.clone(), Box::from(v.borrow()))
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K: ?Sized, V: ?Sized, S> LiteMap<K, V, S>
where
K: Ord,
S: Store<K, V>,
{
/// Get the value associated with `key`, if it exists.
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// assert_eq!(map.get(&1), Some(&"one"));
/// assert_eq!(map.get(&3), None);
/// ```
pub fn get<Q>(&self, key: &Q) -> Option<&V>
where
K: Borrow<Q>,
Q: Ord + ?Sized,
{
match self.find_index(key) {
#[allow(clippy::unwrap_used)] // find_index returns a valid index
Ok(found) => Some(self.values.lm_get(found).unwrap().1),
Err(_) => None,
}
}
/// Binary search the map with `predicate` to find a key, returning the value.
pub fn get_by(&self, predicate: impl FnMut(&K) -> Ordering) -> Option<&V> {
let index = self.values.lm_binary_search_by(predicate).ok()?;
self.values.lm_get(index).map(|(_, v)| v)
}
/// Returns whether `key` is contained in this map
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// assert!(map.contains_key(&1));
/// assert!(!map.contains_key(&3));
/// ```
pub fn contains_key<Q>(&self, key: &Q) -> bool
where
K: Borrow<Q>,
Q: Ord + ?Sized,
{
self.find_index(key).is_ok()
}
/// Obtain the index for a given key, or if the key is not found, the index
/// at which it would be inserted.
///
/// (The return value works equivalently to [`slice::binary_search_by()`])
///
/// The indices returned can be used with [`Self::get_indexed()`]. Prefer using
/// [`Self::get()`] directly where possible.
#[inline]
pub fn find_index<Q>(&self, key: &Q) -> Result<usize, usize>
where
K: Borrow<Q>,
Q: Ord + ?Sized,
{
self.values.lm_binary_search_by(|k| k.borrow().cmp(key))
}
}
impl<K: ?Sized, V: ?Sized, S> LiteMap<K, V, S>
where
S: StoreSlice<K, V>,
{
/// Creates a new [`LiteMap`] from a range of the current [`LiteMap`].
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// map.insert(3, "three");
///
/// let mut sub_map = map.get_indexed_range(1..3).expect("valid range");
/// assert_eq!(sub_map.get(&1), None);
/// assert_eq!(sub_map.get(&2), Some(&"two"));
/// assert_eq!(sub_map.get(&3), Some(&"three"));
/// ```
pub fn get_indexed_range(&self, range: Range<usize>) -> Option<LiteMap<K, V, &S::Slice>> {
let subslice = self.values.lm_get_range(range)?;
Some(LiteMap {
values: subslice,
_key_type: PhantomData,
_value_type: PhantomData,
})
}
/// Borrows this [`LiteMap`] as one of its slice type.
///
/// This can be useful in situations where you need a `LiteMap` by value but do not want
/// to clone the owned version.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
///
/// let borrowed_map = map.as_sliced();
/// assert_eq!(borrowed_map.get(&1), Some(&"one"));
/// assert_eq!(borrowed_map.get(&2), Some(&"two"));
/// ```
pub fn as_sliced(&self) -> LiteMap<K, V, &S::Slice> {
// Won't panic: 0..self.len() is within range
#[allow(clippy::unwrap_used)]
let subslice = self.values.lm_get_range(0..self.len()).unwrap();
LiteMap {
values: subslice,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Borrows the backing buffer of this [`LiteMap`] as its slice type.
///
/// The slice will be sorted.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
///
/// let slice = map.as_slice();
/// assert_eq!(slice, &[(1, "one"), (2, "two")]);
/// ```
pub fn as_slice(&self) -> &S::Slice {
// Won't panic: 0..self.len() is within range
#[allow(clippy::unwrap_used)]
self.values.lm_get_range(0..self.len()).unwrap()
}
}
impl<'a, K: 'a, V: 'a, S> LiteMap<K, V, S>
where
S: Store<K, V>,
{
/// Returns a new [`LiteMap`] with keys and values borrowed from this one.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<Box<usize>, String> = LiteMap::new_vec();
/// map.insert(Box::new(1), "one".to_string());
/// map.insert(Box::new(2), "two".to_string());
///
/// let borrowed_map: LiteMap<&usize, &str> = map.to_borrowed_keys_values();
///
/// assert_eq!(borrowed_map.get(&1), Some(&"one"));
/// ```
pub fn to_borrowed_keys_values<KB: ?Sized, VB: ?Sized, SB>(
&'a self,
) -> LiteMap<&'a KB, &'a VB, SB>
where
K: Borrow<KB>,
V: Borrow<VB>,
SB: StoreMut<&'a KB, &'a VB>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(k.borrow(), v.borrow())
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Returns a new [`LiteMap`] with keys borrowed from this one and cloned values.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<Box<usize>, String> = LiteMap::new_vec();
/// map.insert(Box::new(1), "one".to_string());
/// map.insert(Box::new(2), "two".to_string());
///
/// let borrowed_map: LiteMap<&usize, String> = map.to_borrowed_keys();
///
/// assert_eq!(borrowed_map.get(&1), Some(&"one".to_string()));
/// ```
pub fn to_borrowed_keys<KB: ?Sized, SB>(&'a self) -> LiteMap<&'a KB, V, SB>
where
K: Borrow<KB>,
V: Clone,
SB: StoreMut<&'a KB, V>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(k.borrow(), v.clone())
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Returns a new [`LiteMap`] with values borrowed from this one and cloned keys.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map: LiteMap<Box<usize>, String> = LiteMap::new_vec();
/// map.insert(Box::new(1), "one".to_string());
/// map.insert(Box::new(2), "two".to_string());
///
/// let borrowed_map: LiteMap<Box<usize>, &str> = map.to_borrowed_values();
///
/// assert_eq!(borrowed_map.get(&1), Some(&"one"));
/// ```
pub fn to_borrowed_values<VB: ?Sized, SB>(&'a self) -> LiteMap<K, &'a VB, SB>
where
K: Clone,
V: Borrow<VB>,
SB: StoreMut<K, &'a VB>,
{
let mut values = SB::lm_with_capacity(self.len());
for i in 0..self.len() {
#[allow(clippy::unwrap_used)] // iterating over our own length
let (k, v) = self.values.lm_get(i).unwrap();
values.lm_push(k.clone(), v.borrow())
}
LiteMap {
values,
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K, V, S> LiteMap<K, V, S>
where
S: StoreMut<K, V>,
{
/// Construct a new [`LiteMap`] with a given capacity
pub fn with_capacity(capacity: usize) -> Self {
Self {
values: S::lm_with_capacity(capacity),
_key_type: PhantomData,
_value_type: PhantomData,
}
}
/// Remove all elements from the [`LiteMap`]
pub fn clear(&mut self) {
self.values.lm_clear()
}
/// Reserve capacity for `additional` more elements to be inserted into
/// the [`LiteMap`] to avoid frequent reallocations.
///
/// See [`Vec::reserve()`] for more information.
///
/// [`Vec::reserve()`]: alloc::vec::Vec::reserve
pub fn reserve(&mut self, additional: usize) {
self.values.lm_reserve(additional)
}
}
impl<K, V, S> LiteMap<K, V, S>
where
K: Ord,
S: StoreMut<K, V>,
{
/// Get the value associated with `key`, if it exists, as a mutable reference.
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// if let Some(mut v) = map.get_mut(&1) {
/// *v = "uno";
/// }
/// assert_eq!(map.get(&1), Some(&"uno"));
/// ```
pub fn get_mut<Q>(&mut self, key: &Q) -> Option<&mut V>
where
K: Borrow<Q>,
Q: Ord + ?Sized,
{
match self.find_index(key) {
#[allow(clippy::unwrap_used)] // find_index returns a valid index
Ok(found) => Some(self.values.lm_get_mut(found).unwrap().1),
Err(_) => None,
}
}
/// Appends `value` with `key` to the end of the underlying vector, returning
/// `key` and `value` _if it failed_. Useful for extending with an existing
/// sorted list.
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// assert!(map.try_append(1, "uno").is_none());
/// assert!(map.try_append(3, "tres").is_none());
///
/// assert!(
/// matches!(map.try_append(3, "tres-updated"), Some((3, "tres-updated"))),
/// "append duplicate of last key",
/// );
///
/// assert!(
/// matches!(map.try_append(2, "dos"), Some((2, "dos"))),
/// "append out of order"
/// );
///
/// assert_eq!(map.get(&1), Some(&"uno"));
///
/// // contains the original value for the key: 3
/// assert_eq!(map.get(&3), Some(&"tres"));
///
/// // not appended since it wasn't in order
/// assert_eq!(map.get(&2), None);
/// ```
#[must_use]
pub fn try_append(&mut self, key: K, value: V) -> Option<(K, V)> {
if let Some(last) = self.values.lm_last() {
if last.0 >= &key {
return Some((key, value));
}
}
self.values.lm_push(key, value);
None
}
/// Insert `value` with `key`, returning the existing value if it exists.
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// assert_eq!(map.get(&1), Some(&"one"));
/// assert_eq!(map.get(&3), None);
/// ```
pub fn insert(&mut self, key: K, value: V) -> Option<V> {
self.insert_save_key(key, value).map(|(_, v)| v)
}
/// Version of [`Self::insert()`] that returns both the key and the old value.
fn insert_save_key(&mut self, key: K, value: V) -> Option<(K, V)> {
match self.values.lm_binary_search_by(|k| k.cmp(&key)) {
#[allow(clippy::unwrap_used)] // Index came from binary_search
Ok(found) => Some((
key,
mem::replace(self.values.lm_get_mut(found).unwrap().1, value),
)),
Err(ins) => {
self.values.lm_insert(ins, key, value);
None
}
}
}
/// Attempts to insert a unique entry into the map.
///
/// If `key` is not already in the map, inserts it with the corresponding `value`
/// and returns `None`.
///
/// If `key` is already in the map, no change is made to the map, and the key and value
/// are returned back to the caller.
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(3, "three");
///
/// // 2 is not yet in the map...
/// assert_eq!(map.try_insert(2, "two"), None);
/// assert_eq!(map.len(), 3);
///
/// // ...but now it is.
/// assert_eq!(map.try_insert(2, "TWO"), Some((2, "TWO")));
/// assert_eq!(map.len(), 3);
/// ```
pub fn try_insert(&mut self, key: K, value: V) -> Option<(K, V)> {
match self.values.lm_binary_search_by(|k| k.cmp(&key)) {
Ok(_) => Some((key, value)),
Err(ins) => {
self.values.lm_insert(ins, key, value);
None
}
}
}
/// Attempts to insert a unique entry into the map.
///
/// If `key` is not already in the map, invokes the closure to compute `value`, inserts
/// the pair into the map, and returns a reference to the value. The closure is passed
/// a reference to the `key` argument.
///
/// If `key` is already in the map, a reference to the existing value is returned.
///
/// Additionally, the index of the value in the map is returned. If it is not desirable
/// to hold on to the mutable reference's lifetime, the index can be used to access the
/// element via [`LiteMap::get_indexed()`].
///
/// The closure returns a `Result` to allow for a fallible insertion function. If the
/// creation of `value` is infallible, you can use [`core::convert::Infallible`].
///
/// ```
/// use litemap::LiteMap;
///
/// /// Helper function to unwrap an `Infallible` result from the insertion function
/// fn unwrap_infallible<T>(result: Result<T, core::convert::Infallible>) -> T {
/// result.unwrap_or_else(|never| match never {})
/// }
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(3, "three");
///
/// // 2 is not yet in the map...
/// let result1 = unwrap_infallible(
/// map.try_get_or_insert(2, |_| Ok("two"))
/// );
/// assert_eq!(result1.1, &"two");
/// assert_eq!(map.len(), 3);
///
/// // ...but now it is.
/// let result1 = unwrap_infallible(
/// map.try_get_or_insert(2, |_| Ok("TWO"))
/// );
/// assert_eq!(result1.1, &"two");
/// assert_eq!(map.len(), 3);
/// ```
pub fn try_get_or_insert<E>(
&mut self,
key: K,
value: impl FnOnce(&K) -> Result<V, E>,
) -> Result<(usize, &V), E> {
let idx = match self.values.lm_binary_search_by(|k| k.cmp(&key)) {
Ok(idx) => idx,
Err(idx) => {
let value = value(&key)?;
self.values.lm_insert(idx, key, value);
idx
}
};
#[allow(clippy::unwrap_used)] // item at idx found or inserted above
Ok((idx, self.values.lm_get(idx).unwrap().1))
}
/// Remove the value at `key`, returning it if it exists.
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// assert_eq!(map.remove(&1), Some("one"));
/// assert_eq!(map.get(&1), None);
/// ```
pub fn remove<Q>(&mut self, key: &Q) -> Option<V>
where
K: Borrow<Q>,
Q: Ord + ?Sized,
{
match self.values.lm_binary_search_by(|k| k.borrow().cmp(key)) {
Ok(found) => Some(self.values.lm_remove(found).1),
Err(_) => None,
}
}
}
impl<'a, K: 'a, V: 'a, S> LiteMap<K, V, S>
where
K: Ord,
S: StoreIntoIterator<K, V> + StoreFromIterator<K, V>,
{
/// Insert all elements from `other` into this `LiteMap`.
///
/// If `other` contains keys that already exist in `self`, the values in `other` replace the
/// corresponding ones in `self`, and the rejected items from `self` are returned as a new
/// `LiteMap`. Otherwise, `None` is returned.
///
/// The implementation of this function is optimized if `self` and `other` have no overlap.
///
/// # Examples
///
/// ```
/// use litemap::LiteMap;
///
/// let mut map1 = LiteMap::new_vec();
/// map1.insert(1, "one");
/// map1.insert(2, "two");
///
/// let mut map2 = LiteMap::new_vec();
/// map2.insert(2, "TWO");
/// map2.insert(4, "FOUR");
///
/// let leftovers = map1.extend_from_litemap(map2);
///
/// assert_eq!(map1.len(), 3);
/// assert_eq!(map1.get(&1), Some("one").as_ref());
/// assert_eq!(map1.get(&2), Some("TWO").as_ref());
/// assert_eq!(map1.get(&4), Some("FOUR").as_ref());
///
/// let map3 = leftovers.expect("Duplicate keys");
/// assert_eq!(map3.len(), 1);
/// assert_eq!(map3.get(&2), Some("two").as_ref());
/// ```
pub fn extend_from_litemap(&mut self, other: Self) -> Option<Self> {
if self.is_empty() {
self.values = other.values;
return None;
}
if other.is_empty() {
return None;
}
if self.last().map(|(k, _)| k) < other.first().map(|(k, _)| k) {
// append other to self
self.values.lm_extend_end(other.values);
None
} else if self.first().map(|(k, _)| k) > other.last().map(|(k, _)| k) {
// prepend other to self
self.values.lm_extend_start(other.values);
None
} else {
// insert every element
let leftover_tuples = other
.values
.lm_into_iter()
.filter_map(|(k, v)| self.insert_save_key(k, v))
.collect();
let ret = LiteMap {
values: leftover_tuples,
_key_type: PhantomData,
_value_type: PhantomData,
};
if ret.is_empty() {
None
} else {
Some(ret)
}
}
}
}
impl<K, V, S> Default for LiteMap<K, V, S>
where
S: Store<K, V> + Default,
{
fn default() -> Self {
Self {
values: S::default(),
_key_type: PhantomData,
_value_type: PhantomData,
}
}
}
impl<K, V, S> Index<&'_ K> for LiteMap<K, V, S>
where
K: Ord,
S: Store<K, V>,
{
type Output = V;
fn index(&self, key: &K) -> &V {
#[allow(clippy::panic)] // documented
match self.get(key) {
Some(v) => v,
None => panic!("no entry found for key"),
}
}
}
impl<K, V, S> IndexMut<&'_ K> for LiteMap<K, V, S>
where
K: Ord,
S: StoreMut<K, V>,
{
fn index_mut(&mut self, key: &K) -> &mut V {
#[allow(clippy::panic)] // documented
match self.get_mut(key) {
Some(v) => v,
None => panic!("no entry found for key"),
}
}
}
impl<K, V, S> FromIterator<(K, V)> for LiteMap<K, V, S>
where
K: Ord,
S: StoreFromIterable<K, V>,
{
fn from_iter<I: IntoIterator<Item = (K, V)>>(iter: I) -> Self {
let values = S::lm_sort_from_iter(iter);
Self::from_sorted_store_unchecked(values)
}
}
impl<'a, K: 'a, V: 'a, S> LiteMap<K, V, S>
where
S: StoreIterable<'a, K, V>,
{
/// Produce an ordered iterator over key-value pairs
pub fn iter(&'a self) -> impl DoubleEndedIterator<Item = (&'a K, &'a V)> {
self.values.lm_iter()
}
/// Produce an ordered iterator over keys
pub fn iter_keys(&'a self) -> impl DoubleEndedIterator<Item = &'a K> {
self.values.lm_iter().map(|val| val.0)
}
/// Produce an iterator over values, ordered by their keys
pub fn iter_values(&'a self) -> impl DoubleEndedIterator<Item = &'a V> {
self.values.lm_iter().map(|val| val.1)
}
}
impl<'a, K: 'a, V: 'a, S> LiteMap<K, V, S>
where
S: StoreIterableMut<'a, K, V>,
{
/// Produce an ordered mutable iterator over key-value pairs
pub fn iter_mut(&'a mut self) -> impl DoubleEndedIterator<Item = (&'a K, &'a mut V)> {
self.values.lm_iter_mut()
}
}
impl<K, V, S> IntoIterator for LiteMap<K, V, S>
where
S: StoreIntoIterator<K, V>,
{
type Item = (K, V);
type IntoIter = S::KeyValueIntoIter;
fn into_iter(self) -> Self::IntoIter {
self.values.lm_into_iter()
}
}
impl<K, V, S> LiteMap<K, V, S>
where
S: StoreMut<K, V>,
{
/// Retains only the elements specified by the predicate.
///
/// In other words, remove all elements such that `f((&k, &v))` returns `false`.
///
/// # Example
///
/// ```rust
/// use litemap::LiteMap;
///
/// let mut map = LiteMap::new_vec();
/// map.insert(1, "one");
/// map.insert(2, "two");
/// map.insert(3, "three");
///
/// // Retain elements with odd keys
/// map.retain(|k, _| k % 2 == 1);
///
/// assert_eq!(map.get(&1), Some(&"one"));
/// assert_eq!(map.get(&2), None);
/// ```
#[inline]
pub fn retain<F>(&mut self, predicate: F)
where
F: FnMut(&K, &V) -> bool,
{
self.values.lm_retain(predicate)
}
}
impl<'a, K, V> LiteMap<K, V, &'a [(K, V)]> {
/// Const version of [`LiteMap::len()`] for a slice store.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// static map: LiteMap<&str, usize, &[(&str, usize)]> =
/// LiteMap::from_sorted_store_unchecked(&[("a", 11), ("b", 22)]);
/// static len: usize = map.const_len();
/// assert_eq!(len, 2);
/// ```
#[inline]
pub const fn const_len(&self) -> usize {
self.values.len()
}
/// Const version of [`LiteMap::is_empty()`] for a slice store.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// static map: LiteMap<&str, usize, &[(&str, usize)]> =
/// LiteMap::from_sorted_store_unchecked(&[]);
/// static is_empty: bool = map.const_is_empty();
/// assert!(is_empty);
/// ```
#[inline]
pub const fn const_is_empty(&self) -> bool {
self.values.is_empty()
}
/// Const version of [`LiteMap::get_indexed()`] for a slice store.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// # Panics
///
/// Panics if the index is out of bounds.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// static map: LiteMap<&str, usize, &[(&str, usize)]> =
/// LiteMap::from_sorted_store_unchecked(&[("a", 11), ("b", 22)]);
/// static t: &(&str, usize) = map.const_get_indexed_or_panic(0);
/// assert_eq!(t.0, "a");
/// assert_eq!(t.1, 11);
/// ```
#[inline]
#[allow(clippy::indexing_slicing)] // documented
pub const fn const_get_indexed_or_panic(&self, index: usize) -> &'a (K, V) {
&self.values[index]
}
}
const fn const_cmp_bytes(a: &[u8], b: &[u8]) -> Ordering {
let (max, default) = if a.len() == b.len() {
(a.len(), Ordering::Equal)
} else if a.len() < b.len() {
(a.len(), Ordering::Less)
} else {
(b.len(), Ordering::Greater)
};
let mut i = 0;
#[allow(clippy::indexing_slicing)] // indexes in range by above checks
while i < max {
if a[i] == b[i] {
i += 1;
continue;
} else if a[i] < b[i] {
return Ordering::Less;
} else {
return Ordering::Greater;
}
}
default
}
impl<'a, V> LiteMap<&'a str, V, &'a [(&'a str, V)]> {
/// Const function to get the value associated with a `&str` key, if it exists.
///
/// Also returns the index of the value.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// static map: LiteMap<&str, usize, &[(&str, usize)]> =
/// LiteMap::from_sorted_store_unchecked(&[
/// ("abc", 11),
/// ("bcd", 22),
/// ("cde", 33),
/// ("def", 44),
/// ("efg", 55),
/// ]);
///
/// static d: Option<(usize, &usize)> = map.const_get_with_index("def");
/// assert_eq!(d, Some((3, &44)));
///
/// static n: Option<(usize, &usize)> = map.const_get_with_index("dng");
/// assert_eq!(n, None);
/// ```
pub const fn const_get_with_index(&self, key: &str) -> Option<(usize, &'a V)> {
let mut i = 0;
let mut j = self.const_len();
while i < j {
let mid = (i + j) / 2;
#[allow(clippy::indexing_slicing)] // in range
let x = &self.values[mid];
match const_cmp_bytes(key.as_bytes(), x.0.as_bytes()) {
Ordering::Equal => return Some((mid, &x.1)),
Ordering::Greater => i = mid + 1,
Ordering::Less => j = mid,
};
}
None
}
}
impl<'a, V> LiteMap<&'a [u8], V, &'a [(&'a [u8], V)]> {
/// Const function to get the value associated with a `&[u8]` key, if it exists.
///
/// Also returns the index of the value.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// # Examples
///
/// ```rust
/// use litemap::LiteMap;
///
/// static map: LiteMap<&[u8], usize, &[(&[u8], usize)]> =
/// LiteMap::from_sorted_store_unchecked(&[
/// (b"abc", 11),
/// (b"bcd", 22),
/// (b"cde", 33),
/// (b"def", 44),
/// (b"efg", 55),
/// ]);
///
/// static d: Option<(usize, &usize)> = map.const_get_with_index(b"def");
/// assert_eq!(d, Some((3, &44)));
///
/// static n: Option<(usize, &usize)> = map.const_get_with_index(b"dng");
/// assert_eq!(n, None);
/// ```
pub const fn const_get_with_index(&self, key: &[u8]) -> Option<(usize, &'a V)> {
let mut i = 0;
let mut j = self.const_len();
while i < j {
let mid = (i + j) / 2;
#[allow(clippy::indexing_slicing)] // in range
let x = &self.values[mid];
match const_cmp_bytes(key, x.0) {
Ordering::Equal => return Some((mid, &x.1)),
Ordering::Greater => i = mid + 1,
Ordering::Less => j = mid,
};
}
None
}
}
macro_rules! impl_const_get_with_index_for_integer {
($integer:ty) => {
impl<'a, V> LiteMap<$integer, V, &'a [($integer, V)]> {
/// Const function to get the value associated with an integer key, if it exists.
///
/// Note: This function will no longer be needed if const trait behavior is stabilized.
///
/// Also returns the index of the value.
pub const fn const_get_with_index(&self, key: $integer) -> Option<(usize, &'a V)> {
let mut i = 0;
let mut j = self.const_len();
while i < j {
let mid = (i + j) / 2;
#[allow(clippy::indexing_slicing)] // in range
let x = &self.values[mid];
if key == x.0 {
return Some((mid, &x.1));
} else if key > x.0 {
i = mid + 1;
} else {
j = mid;
}
}
return None;
}
}
};
}
impl_const_get_with_index_for_integer!(u8);
impl_const_get_with_index_for_integer!(u16);
impl_const_get_with_index_for_integer!(u32);
impl_const_get_with_index_for_integer!(u64);
impl_const_get_with_index_for_integer!(u128);
impl_const_get_with_index_for_integer!(usize);
impl_const_get_with_index_for_integer!(i8);
impl_const_get_with_index_for_integer!(i16);
impl_const_get_with_index_for_integer!(i32);
impl_const_get_with_index_for_integer!(i64);
impl_const_get_with_index_for_integer!(i128);
impl_const_get_with_index_for_integer!(isize);
#[cfg(test)]
mod test {
use super::*;
#[test]
fn from_iterator() {
let mut expected = LiteMap::with_capacity(4);
expected.insert(1, "updated-one");
expected.insert(2, "original-two");
expected.insert(3, "original-three");
expected.insert(4, "updated-four");
let actual = [
(1, "original-one"),
(2, "original-two"),
(4, "original-four"),
(4, "updated-four"),
(1, "updated-one"),
(3, "original-three"),
]
.into_iter()
.collect::<LiteMap<_, _>>();
assert_eq!(expected, actual);
}
fn make_13() -> LiteMap<usize, &'static str> {
let mut result = LiteMap::new();
result.insert(1, "one");
result.insert(3, "three");
result
}
fn make_24() -> LiteMap<usize, &'static str> {
let mut result = LiteMap::new();
result.insert(2, "TWO");
result.insert(4, "FOUR");
result
}
fn make_46() -> LiteMap<usize, &'static str> {
let mut result = LiteMap::new();
result.insert(4, "four");
result.insert(6, "six");
result
}
#[test]
fn extend_from_litemap_append() {
let mut map = LiteMap::new();
map.extend_from_litemap(make_13())
.ok_or(())
.expect_err("Append to empty map");
map.extend_from_litemap(make_46())
.ok_or(())
.expect_err("Append to lesser map");
assert_eq!(map.len(), 4);
}
#[test]
fn extend_from_litemap_prepend() {
let mut map = LiteMap::new();
map.extend_from_litemap(make_46())
.ok_or(())
.expect_err("Prepend to empty map");
map.extend_from_litemap(make_13())
.ok_or(())
.expect_err("Prepend to lesser map");
assert_eq!(map.len(), 4);
}
#[test]
fn extend_from_litemap_insert() {
let mut map = LiteMap::new();
map.extend_from_litemap(make_13())
.ok_or(())
.expect_err("Append to empty map");
map.extend_from_litemap(make_24())
.ok_or(())
.expect_err("Insert with no conflict");
map.extend_from_litemap(make_46())
.ok_or(())
.expect("Insert with conflict");
assert_eq!(map.len(), 5);
}
#[test]
fn test_const_cmp_bytes() {
let strs = &["a", "aa", "abc", "abde", "bcd", "bcde"];
for i in 0..strs.len() {
for j in 0..strs.len() {
let a = strs[i].as_bytes();
let b = strs[j].as_bytes();
assert_eq!(a.cmp(b), const_cmp_bytes(a, b));
}
}
}
#[test]
fn into_iterator() {
let mut map = LiteMap::<_, _, Vec<(_, _)>>::new();
map.insert(4, "four");
map.insert(6, "six");
let mut reference = vec![(6, "six"), (4, "four")];
for i in map {
let r = reference.pop().unwrap();
assert_eq!(r, i);
}
assert!(reference.is_empty());
}
}