feat: add PoC collections crate

Author: robjtede

.cspell.yml

@@ -2,6 +2,7 @@ version: "0.2"
 words:
   - actix
   - ahash
+  - arrayvec
   - bytestring
   - cbor
   - clippy
@@ -42,5 +43,6 @@ words:
   - splitn
   - struct
   - taplo
+  - tinyvec
   - trybuild
   - vals

Cargo.lock

@@ -5,7 +5,7 @@ members = [
   "./actix-hash",
   "./actix-web-lab-derive",
   "./actix-web-lab",
-  "./russe",
+  "./russe", "collections",
 ]
 
 [workspace.package]

Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "collections"
+version = "0.1.0"
+description = "Collection traits and implementations for common crates"
+repository.workspace = true
+license.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+arrayvec = "0.7"
+tinyvec = "1"
+
+[lints]
+workspace = true

collections/Cargo.toml

@@ -0,0 +1,44 @@
+use arrayvec::ArrayVec;
+
+use super::List;
+use super::MutableList;
+
+impl<T, const CAP: usize> List<T> for ArrayVec<T, CAP> {
+    fn len(&self) -> usize {
+        ArrayVec::len(self)
+    }
+
+    fn get(&self, idx: usize) -> Option<&T> {
+        <[_]>::get(self, idx)
+    }
+}
+
+impl<T, const CAP: usize> MutableList<T> for ArrayVec<T, CAP> {
+    fn append(&mut self, element: T) {
+        self.push(element);
+    }
+
+    fn get_mut(&mut self, idx: usize) -> Option<&mut T> {
+        <[_]>::get_mut(self, idx)
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let mut vec = ArrayVec::<_, 8>::new();
+
+        assert_eq!(0, List::len(&vec));
+        assert!(List::is_empty(&vec));
+
+        MutableList::append(&mut vec, 1);
+
+        assert_eq!(1, List::len(&vec));
+        assert!(!List::is_empty(&vec));
+
+        assert_eq!(&1, List::get(&vec, 0).unwrap());
+    }
+}

collections/src/arrayvec.rs

@@ -0,0 +1,23 @@
+//! Collection traits.
+
+#![allow(missing_docs)]
+
+mod arrayvec;
+mod tinyvec;
+mod vec;
+
+pub trait List<T> {
+    fn len(&self) -> usize;
+
+    fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    fn get(&self, idx: usize) -> Option<&T>;
+}
+
+pub trait MutableList<T>: List<T> {
+    fn append(&mut self, element: T);
+
+    fn get_mut(&mut self, idx: usize) -> Option<&mut T>;
+}

collections/src/lib.rs

@@ -0,0 +1,45 @@
+use tinyvec::Array;
+use tinyvec::ArrayVec;
+
+use super::List;
+use super::MutableList;
+
+impl<A: Array> List<A::Item> for ArrayVec<A> {
+    fn len(&self) -> usize {
+        ArrayVec::len(self)
+    }
+
+    fn get(&self, idx: usize) -> Option<&A::Item> {
+        <[_]>::get(self, idx)
+    }
+}
+
+impl<A: Array> MutableList<A::Item> for ArrayVec<A> {
+    fn append(&mut self, element: A::Item) {
+        self.push(element);
+    }
+
+    fn get_mut(&mut self, idx: usize) -> Option<&mut A::Item> {
+        <[_]>::get_mut(self, idx)
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let mut vec = ArrayVec::<[_; 8]>::new();
+
+        assert_eq!(0, List::len(&vec));
+        assert!(List::is_empty(&vec));
+
+        MutableList::append(&mut vec, 1);
+
+        assert_eq!(1, List::len(&vec));
+        assert!(!List::is_empty(&vec));
+
+        assert_eq!(&1, List::get(&vec, 0).unwrap());
+    }
+}

collections/src/tinyvec.rs

@@ -0,0 +1,42 @@
+use super::List;
+use super::MutableList;
+
+impl<T> List<T> for Vec<T> {
+    fn len(&self) -> usize {
+        Vec::len(self)
+    }
+
+    fn get(&self, idx: usize) -> Option<&T> {
+        <[_]>::get(self, idx)
+    }
+}
+
+impl<T> MutableList<T> for Vec<T> {
+    fn append(&mut self, element: T) {
+        self.push(element);
+    }
+
+    fn get_mut(&mut self, idx: usize) -> Option<&mut T> {
+        <[_]>::get_mut(self, idx)
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let mut vec = vec![];
+
+        assert_eq!(0, List::len(&vec));
+        assert!(List::is_empty(&vec));
+
+        MutableList::append(&mut vec, 1);
+
+        assert_eq!(1, List::len(&vec));
+        assert!(!List::is_empty(&vec));
+
+        assert_eq!(&1, List::get(&vec, 0).unwrap());
+    }
+}