1 files changed, 76 insertions, 0 deletions
diff --git a/third_party/rust/tinystr/src/ule.rs b/third_party/rust/tinystr/src/ule.rs
new file mode 100644
index 0000000000..0fa212095f
--- /dev/null
+++ b/third_party/rust/tinystr/src/ule.rs
@@ -0,0 +1,76 @@
+// 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
+// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+use crate::TinyAsciiStr;
+use zerovec::maps::ZeroMapKV;
+use zerovec::ule::*;
+use zerovec::{ZeroSlice, ZeroVec};
+
+// Safety (based on the safety checklist on the ULE trait):
+//  1. CharULE does not include any uninitialized or padding bytes.
+//     (achieved by `#[repr(transparent)]` on a type that satisfies this invariant)
+//  2. CharULE is aligned to 1 byte.
+//     (achieved by `#[repr(transparent)]` on a type that satisfies this invariant)
+//  3. The impl of validate_byte_slice() returns an error if any byte is not valid.
+//  4. The impl of validate_byte_slice() returns an error if there are extra bytes.
+//  5. The other ULE methods use the default impl.
+//  6. CharULE byte equality is semantic equality
+unsafe impl<const N: usize> ULE for TinyAsciiStr<N> {
+    #[inline]
+    fn validate_byte_slice(bytes: &[u8]) -> Result<(), ZeroVecError> {
+        if bytes.len() % N != 0 {
+            return Err(ZeroVecError::length::<Self>(bytes.len()));
+        }
+        // Validate the bytes
+        for chunk in bytes.chunks_exact(N) {
+            let _ = TinyAsciiStr::<N>::from_bytes_inner(chunk, 0, N, true)
+                .map_err(|_| ZeroVecError::parse::<Self>())?;
+        }
+        Ok(())
+    }
+}
+
+impl<const N: usize> AsULE for TinyAsciiStr<N> {
+    type ULE = Self;
+
+    #[inline]
+    fn to_unaligned(self) -> Self::ULE {
+        self
+    }
+
+    #[inline]
+    fn from_unaligned(unaligned: Self::ULE) -> Self {
+        unaligned
+    }
+}
+
+impl<'a, const N: usize> ZeroMapKV<'a> for TinyAsciiStr<N> {
+    type Container = ZeroVec<'a, TinyAsciiStr<N>>;
+    type Slice = ZeroSlice<TinyAsciiStr<N>>;
+    type GetType = TinyAsciiStr<N>;
+    type OwnedType = TinyAsciiStr<N>;
+}
+
+#[cfg(test)]
+mod test {
+    use crate::*;
+    use zerovec::*;
+
+    #[test]
+    fn test_zerovec() {
+        let mut vec = ZeroVec::<TinyAsciiStr<7>>::new();
+
+        vec.with_mut(|v| v.push("foobar".parse().unwrap()));
+        vec.with_mut(|v| v.push("baz".parse().unwrap()));
+        vec.with_mut(|v| v.push("quux".parse().unwrap()));
+
+        let bytes = vec.as_bytes();
+
+        let vec: ZeroVec<TinyAsciiStr<7>> = ZeroVec::parse_byte_slice(bytes).unwrap();
+
+        assert_eq!(&*vec.get(0).unwrap(), "foobar");
+        assert_eq!(&*vec.get(1).unwrap(), "baz");
+        assert_eq!(&*vec.get(2).unwrap(), "quux");
+    }
+}