Remove AsVarULE (unicode-org#1126)

utils/yoke/derive/examples/derive.rs

@@ -23,7 +23,7 @@ pub struct CowExample<'a> {
 
 #[derive(Yokeable, ZeroCopyFrom)]
 pub struct ZeroVecExample<'a> {
-    var: VarZeroVec<'a, String>,
+    var: VarZeroVec<'a, str>,
     vec: ZeroVec<'a, u16>,
 }
 
@@ -34,7 +34,7 @@ pub struct ZeroVecExample<'a> {
 #[derive(Yokeable)]
 #[yoke(prove_covariance_manually)]
 pub struct ZeroMapExample<'a> {
-    map: ZeroMap<'a, String, u16>,
+    map: ZeroMap<'a, str, u16>,
 }
 
 fn main() {}

utils/zerovec/README.md

@@ -57,12 +57,12 @@ pub struct DataStruct<'data> {
     #[serde(borrow)]
     nums: ZeroVec<'data, u32>,
     #[serde(borrow)]
-    strs: VarZeroVec<'data, String>,
+    strs: VarZeroVec<'data, str>,
 }
 
 let data = DataStruct {
     nums: ZeroVec::from_slice(&[211, 281, 421, 461]),
-    strs: VarZeroVec::from(&["hello".to_string(), "world".to_string()] as &[_]),
+    strs: VarZeroVec::from(&["hello", "world"] as &[_]),
 };
 let bincode_bytes = bincode::serialize(&data)
     .expect("Serialization should be successful");

utils/zerovec/benches/vzv.rs

@@ -45,8 +45,9 @@ fn overview_bench(c: &mut Criterion) {
     // Same as vzv/char_count/vzv but with different inputs
     let seed = 42;
     let (string_vec, _) = random_alphanums(2..=10, 100, seed);
-    let bytes: Vec<u8> = VarZeroVec::get_serializable_bytes(string_vec.as_slice()).unwrap();
-    let vzv = VarZeroVec::<String>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
+    let bytes: Vec<u8> =
+        VarZeroVec::<str>::get_serializable_bytes::<String>(string_vec.as_slice()).unwrap();
+    let vzv = VarZeroVec::<str>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
 
     c.bench_function("vzv/overview", |b| {
         b.iter(|| {
@@ -72,8 +73,9 @@ fn overview_bench(c: &mut Criterion) {
 fn char_count_benches(c: &mut Criterion) {
     let seed = 2021;
     let (string_vec, _) = random_alphanums(2..=20, 100, seed);
-    let bytes: Vec<u8> = VarZeroVec::get_serializable_bytes(string_vec.as_slice()).unwrap();
-    let vzv = VarZeroVec::<String>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
+    let bytes: Vec<u8> =
+        VarZeroVec::<str>::get_serializable_bytes::<String>(string_vec.as_slice()).unwrap();
+    let vzv = VarZeroVec::<str>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
 
     // *** Count chars in vec of 100 strings ***
     c.bench_function("vzv/char_count/slice", |b| {
@@ -99,8 +101,9 @@ fn binary_search_benches(c: &mut Criterion) {
     let seed = 2021;
     let (string_vec, seed) = random_alphanums(2..=20, 500, seed);
     let (needles, _) = random_alphanums(2..=20, 10, seed);
-    let bytes: Vec<u8> = VarZeroVec::get_serializable_bytes(string_vec.as_slice()).unwrap();
-    let vzv = VarZeroVec::<String>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
+    let bytes: Vec<u8> =
+        VarZeroVec::<str>::get_serializable_bytes::<String>(string_vec.as_slice()).unwrap();
+    let vzv = VarZeroVec::<str>::parse_byte_slice(black_box(bytes.as_slice())).unwrap();
     let single_needle = "lmnop".to_string();
 
     // *** Binary search vec of 500 strings 10 times ***
@@ -139,7 +142,7 @@ fn serde_benches(c: &mut Criterion) {
     let seed = 2021;
     let (string_vec, _) = random_alphanums(2..=20, 100, seed);
     let bincode_vec = bincode::serialize(&string_vec).unwrap();
-    let vzv = VarZeroVec::from(&*string_vec);
+    let vzv: VarZeroVec<str> = VarZeroVec::from(&*string_vec);
     let bincode_vzv = bincode::serialize(&vzv).unwrap();
 
     // *** Deserialize vec of 100 strings ***
@@ -154,7 +157,7 @@ fn serde_benches(c: &mut Criterion) {
 
     // *** Deserialize vec of 100 strings ***
     c.bench_function("vzv/deserialize/string/vzv", |b| {
-        b.iter(|| bincode::deserialize::<VarZeroVec<String>>(black_box(&bincode_vzv)));
+        b.iter(|| bincode::deserialize::<VarZeroVec<str>>(black_box(&bincode_vzv)));
     });
 }
 

utils/zerovec/src/lib.rs

@@ -60,12 +60,12 @@
 //!     #[serde(borrow)]
 //!     nums: ZeroVec<'data, u32>,
 //!     #[serde(borrow)]
-//!     strs: VarZeroVec<'data, String>,
+//!     strs: VarZeroVec<'data, str>,
 //! }
 //!
 //! let data = DataStruct {
 //!     nums: ZeroVec::from_slice(&[211, 281, 421, 461]),
-//!     strs: VarZeroVec::from(&["hello".to_string(), "world".to_string()] as &[_]),
+//!     strs: VarZeroVec::from(&["hello", "world"] as &[_]),
 //! };
 //! let bincode_bytes = bincode::serialize(&data)
 //!     .expect("Serialization should be successful");

utils/zerovec/src/map/kv.rs

@@ -6,32 +6,41 @@ use super::vecs::ZeroVecLike;
 use crate::ule::*;
 use crate::VarZeroVec;
 use crate::ZeroVec;
-use alloc::string::String;
-use alloc::vec::Vec;
+use alloc::boxed::Box;
 use core::cmp::Ordering;
 
 /// Trait marking types which are allowed to be keys or values in [`ZeroMap`](super::ZeroMap).
 ///
 /// Users should not be calling methods of this trait directly, however if you are
-/// implementing your own [`AsULE`] or [`AsVarULE`] type you may wish to implement
+/// implementing your own [`AsULE`] or [`VarULE`] type you may wish to implement
 /// this trait.
 // this lifetime should be a GAT on Container once that is possible
 #[allow(clippy::upper_case_acronyms)] // KV is not an acronym
-pub trait ZeroMapKV<'a>: Sized {
+pub trait ZeroMapKV<'a> {
     /// The container that can be used with this type: [`ZeroVec`] or [`VarZeroVec`].
-    type Container: ZeroVecLike<'a, Self, NeedleType = Self::NeedleType, GetType = Self::GetType>
-        + Sized;
+    type Container: ZeroVecLike<
+            'a,
+            Self,
+            NeedleType = Self::NeedleType,
+            GetType = Self::GetType,
+            OwnedType = Self::OwnedType,
+        > + Sized;
     /// The type to use with `Container::binary_search()`
     ///
     /// This type will be predetermined by the choice of `Self::Container`
     type NeedleType: ?Sized;
-    /// The type produces by `Container::get()`
+    /// The type produced by `Container::get()`
     ///
     /// This type will be predetermined by the choice of `Self::Container`
     type GetType: ?Sized;
     /// The type to use whilst serializing. This may not necessarily be `Self`, however it
     /// must serialize to the exact same thing as `Self`
     type SerializeType: ?Sized;
+    /// The type produced by `Container::replace()` and `Container::remove()`,
+    /// also used during deserialization. If `Self` is human readable serialized,
+    /// deserializing to `Self::OwnedType` should produce the same value once
+    /// passed through `Self::owned_as_self()`
+    type OwnedType;
     /// Convert to a needle for searching
     fn as_needle(&self) -> &Self::NeedleType;
     /// Compare this type with a `Self::GetType`. This must produce the same result as
@@ -42,6 +51,9 @@ pub trait ZeroMapKV<'a>: Sized {
     /// This uses a callback because it's not possible to return owned-or-borrowed
     /// types without GATs
     fn with_ser<R>(g: &Self::GetType, f: impl FnOnce(&Self::SerializeType) -> R) -> R;
+
+    /// Convert an owned value to a borrowed Self
+    fn owned_as_self(o: &Self::OwnedType) -> &Self;
 }
 
 macro_rules! impl_sized_kv {
@@ -51,16 +63,27 @@ macro_rules! impl_sized_kv {
             type NeedleType = $ty;
             type GetType = <$ty as AsULE>::ULE;
             type SerializeType = $ty;
+            type OwnedType = $ty;
+
+            #[inline]
             fn as_needle(&self) -> &Self {
                 self
             }
+
+            #[inline]
             fn cmp_get(&self, g: &Self::GetType) -> Ordering {
                 self.cmp(&$ty::from_unaligned(g))
             }
 
+            #[inline]
             fn with_ser<R>(g: &Self::GetType, f: impl FnOnce(&Self) -> R) -> R {
                 f(&Self::from_unaligned(g))
             }
+
+            #[inline]
+            fn owned_as_self(o: &Self::OwnedType) -> &Self {
+                o
+            }
         }
     };
 }
@@ -75,36 +98,58 @@ impl_sized_kv!(i64);
 impl_sized_kv!(i128);
 impl_sized_kv!(char);
 
-impl<'a> ZeroMapKV<'a> for String {
-    type Container = VarZeroVec<'a, String>;
+impl<'a> ZeroMapKV<'a> for str {
+    type Container = VarZeroVec<'a, str>;
     type NeedleType = str;
     type GetType = str;
     type SerializeType = str;
+    type OwnedType = Box<str>;
+
+    #[inline]
     fn as_needle(&self) -> &str {
         self
     }
+
+    #[inline]
     fn cmp_get(&self, g: &str) -> Ordering {
-        (&**self).cmp(g)
+        (&*self).cmp(g)
     }
 
+    #[inline]
     fn with_ser<R>(g: &str, f: impl FnOnce(&str) -> R) -> R {
         f(g)
     }
+
+    #[inline]
+    fn owned_as_self(o: &Self::OwnedType) -> &Self {
+        o
+    }
 }
 
-impl<'a> ZeroMapKV<'a> for Vec<u8> {
-    type Container = VarZeroVec<'a, Vec<u8>>;
+impl<'a> ZeroMapKV<'a> for [u8] {
+    type Container = VarZeroVec<'a, [u8]>;
     type NeedleType = [u8];
     type GetType = [u8];
     type SerializeType = [u8];
+    type OwnedType = Box<[u8]>;
+
+    #[inline]
     fn as_needle(&self) -> &[u8] {
         self
     }
+
+    #[inline]
     fn cmp_get(&self, g: &[u8]) -> Ordering {
-        (&**self).cmp(g)
+        (&*self).cmp(g)
     }
 
+    #[inline]
     fn with_ser<R>(g: &[u8], f: impl FnOnce(&[u8]) -> R) -> R {
         f(g)
     }
+
+    #[inline]
+    fn owned_as_self(o: &Self::OwnedType) -> &Self {
+        o
+    }
 }

utils/zerovec/src/map/mod.rs

@@ -39,7 +39,7 @@ pub use vecs::ZeroVecLike;
 /// ];
 ///
 /// // Deserializing to ZeroMap requires no heap allocations.
-/// let zero_map: ZeroMap<u32, String> = bincode::deserialize(BINCODE_BYTES)
+/// let zero_map: ZeroMap<u32, str> = bincode::deserialize(BINCODE_BYTES)
 ///     .expect("Should deserialize successfully");
 /// assert_eq!(zero_map.get(&1), Some("one"));
 /// ```
@@ -49,6 +49,8 @@ pub struct ZeroMap<'a, K, V>
 where
     K: ZeroMapKV<'a>,
     V: ZeroMapKV<'a>,
+    K: ?Sized,
+    V: ?Sized,
 {
     pub(crate) keys: K::Container,
     pub(crate) values: V::Container,
@@ -58,6 +60,8 @@ impl<'a, K, V> Default for ZeroMap<'a, K, V>
 where
     K: ZeroMapKV<'a>,
     V: ZeroMapKV<'a>,
+    K: ?Sized,
+    V: ?Sized,
 {
     fn default() -> Self {
         Self {
@@ -71,6 +75,8 @@ impl<'a, K, V> ZeroMap<'a, K, V>
 where
     K: ZeroMapKV<'a>,
     V: ZeroMapKV<'a>,
+    K: ?Sized,
+    V: ?Sized,
 {
     /// Construct a new [`ZeroMap`]
     pub fn new() -> Self {
@@ -116,8 +122,8 @@ where
     /// use zerovec::ZeroMap;
     ///
     /// let mut map = ZeroMap::new();
-    /// map.insert(1, "one".to_owned());
-    /// map.insert(2, "two".to_owned());
+    /// map.insert(&1, "one");
+    /// map.insert(&2, "two");
     /// assert_eq!(map.get(&1), Some("one"));
     /// assert_eq!(map.get(&3), None);
     /// ```
@@ -132,8 +138,8 @@ where
     /// use zerovec::ZeroMap;
     ///
     /// let mut map = ZeroMap::new();
-    /// map.insert(1, "one".to_owned());
-    /// map.insert(2, "two".to_owned());
+    /// map.insert(&1, "one");
+    /// map.insert(&2, "two");
     /// assert_eq!(map.contains_key(&1), true);
     /// assert_eq!(map.contains_key(&3), false);
     /// ```
@@ -147,12 +153,12 @@ where
     /// use zerovec::ZeroMap;
     ///
     /// let mut map = ZeroMap::new();
-    /// map.insert(1, "one".to_owned());
-    /// map.insert(2, "two".to_owned());
+    /// 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> {
+    pub fn insert(&mut self, key: &K, value: &V) -> Option<V::OwnedType> {
         let key_needle = key.as_needle();
         match self.keys.binary_search(key_needle) {
             Ok(index) => Some(self.values.replace(index, value)),
@@ -170,12 +176,12 @@ where
     /// use zerovec::ZeroMap;
     ///
     /// let mut map = ZeroMap::new();
-    /// map.insert(1, "one".to_owned());
-    /// map.insert(2, "two".to_owned());
-    /// assert_eq!(map.remove(&1), Some("one".to_owned()));
+    /// map.insert(&1, "one");
+    /// map.insert(&2, "two");
+    /// assert_eq!(map.remove(&1), Some("one".to_owned().into_boxed_str()));
     /// assert_eq!(map.get(&1), None);
     /// ```
-    pub fn remove(&mut self, key: &K::NeedleType) -> Option<V> {
+    pub fn remove(&mut self, key: &K::NeedleType) -> Option<V::OwnedType> {
         let idx = self.keys.binary_search(key).ok()?;
         self.keys.remove(idx);
         Some(self.values.remove(idx))
@@ -188,13 +194,13 @@ where
     /// use zerovec::ZeroMap;
     ///
     /// let mut map = ZeroMap::new();
-    /// assert!(map.try_append(1, "uno".to_owned()).is_none());
-    /// assert!(map.try_append(3, "tres".to_owned()).is_none());
+    /// assert!(map.try_append(&1, "uno").is_none());
+    /// assert!(map.try_append(&3, "tres").is_none());
     ///
-    /// let unsuccessful = map.try_append(3, "tres-updated".to_owned());
+    /// let unsuccessful = map.try_append(&3, "tres-updated");
     /// assert!(unsuccessful.is_some(), "append duplicate of last key");
     ///
-    /// let unsuccessful = map.try_append(2, "dos".to_owned());
+    /// let unsuccessful = map.try_append(&2, "dos");
     /// assert!(unsuccessful.is_some(), "append out of order");
     ///
     /// assert_eq!(map.get(&1), Some("uno"));
@@ -206,7 +212,7 @@ where
     /// assert_eq!(map.get(&2), None);
     /// ```
     #[must_use]
-    pub fn try_append(&mut self, key: K, value: V) -> Option<(K, V)> {
+    pub fn try_append<'b>(&mut self, key: &'b K, value: &'b V) -> Option<(&'b K, &'b V)> {
         if self.keys.len() != 0 {
             if let Some(last) = self.keys.get(self.keys.len() - 1) {
                 if key.cmp_get(last) != Ordering::Greater {