Rollup merge of #99544 - dylni:expose-utf8lossy, r=Mark-Simulacrum

Expose `Utf8Lossy` as `Utf8Chunks`

This PR changes the feature for `Utf8Lossy` from `str_internals` to `utf8_lossy` and improves the API. This is done to eventually expose the API as stable.

Proposal: rust-lang/libs-team#54
Tracking Issue: #99543

3 files changed, 11 insertions, 8 deletions

diff --git a/library/alloc/src/lib.rs b/library/alloc/src/lib.rs
index 8b6f4054851..e10aaefebe6 100644
--- a/library/alloc/src/lib.rs
+++ b/library/alloc/src/lib.rs
@@ -145,6 +145,7 @@
 #![feature(unchecked_math)]
 #![feature(unicode_internals)]
 #![feature(unsize)]
+#![feature(utf8_chunks)]
 #![feature(std_internals)]
 //
 // Language features:
diff --git a/library/alloc/src/str.rs b/library/alloc/src/str.rs
index d5ed2c4adf4..b94b1b1ce21 100644
--- a/library/alloc/src/str.rs
+++ b/library/alloc/src/str.rs
@@ -71,6 +71,8 @@ pub use core::str::{RSplit, Split};
 pub use core::str::{RSplitN, SplitN};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use core::str::{RSplitTerminator, SplitTerminator};
+#[unstable(feature = "utf8_chunks", issue = "99543")]
+pub use core::str::{Utf8Chunk, Utf8Chunks};
 
 /// Note: `str` in `Concat<str>` is not meaningful here.
 /// This type parameter of the trait only exists to enable another impl.
diff --git a/library/alloc/src/string.rs b/library/alloc/src/string.rs
index a5118e5333b..7bee894d3e4 100644
--- a/library/alloc/src/string.rs
+++ b/library/alloc/src/string.rs
@@ -58,9 +58,9 @@ use core::ops::Bound::{Excluded, Included, Unbounded};
 use core::ops::{self, Index, IndexMut, Range, RangeBounds};
 use core::ptr;
 use core::slice;
-#[cfg(not(no_global_oom_handling))]
-use core::str::lossy;
 use core::str::pattern::Pattern;
+#[cfg(not(no_global_oom_handling))]
+use core::str::Utf8Chunks;
 
 #[cfg(not(no_global_oom_handling))]
 use crate::borrow::{Cow, ToOwned};
@@ -628,11 +628,11 @@ impl String {
     #[cfg(not(no_global_oom_handling))]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub fn from_utf8_lossy(v: &[u8]) -> Cow<'_, str> {
-        let mut iter = lossy::Utf8Lossy::from_bytes(v).chunks();
+        let mut iter = Utf8Chunks::new(v);
 
         let first_valid = if let Some(chunk) = iter.next() {
-            let lossy::Utf8LossyChunk { valid, broken } = chunk;
-            if broken.is_empty() {
+            let valid = chunk.valid();
+            if chunk.invalid().is_empty() {
                 debug_assert_eq!(valid.len(), v.len());
                 return Cow::Borrowed(valid);
             }
@@ -647,9 +647,9 @@ impl String {
         res.push_str(first_valid);
         res.push_str(REPLACEMENT);
 
-        for lossy::Utf8LossyChunk { valid, broken } in iter {
-            res.push_str(valid);
-            if !broken.is_empty() {
+        for chunk in iter {
+            res.push_str(chunk.valid());
+            if !chunk.invalid().is_empty() {
                 res.push_str(REPLACEMENT);
             }
         }