RustPython · youknowone · Jul 29, 2025 · Jul 16, 2025 · Jul 15, 2025 · Jul 28, 2025
diff --git a/common/src/str.rs b/common/src/str.rs
@@ -487,7 +487,7 @@ pub mod levenshtein {
         if a == b { CASE_COST } else { MOVE_COST }
     }
 
-    pub fn levenshtein_distance(a: &str, b: &str, max_cost: usize) -> usize {
+    pub fn levenshtein_distance(a: &[u8], b: &[u8], max_cost: usize) -> usize {
         thread_local! {
             #[allow(clippy::declare_interior_mutable_const)]
             static BUFFER: RefCell<[usize; MAX_STRING_SIZE]> = const {
@@ -499,7 +499,7 @@ pub mod levenshtein {
             return 0;
         }
 
-        let (mut a_bytes, mut b_bytes) = (a.as_bytes(), b.as_bytes());
+        let (mut a_bytes, mut b_bytes) = (a, b);
         let (mut a_begin, mut a_end) = (0usize, a.len());
         let (mut b_begin, mut b_end) = (0usize, b.len());
 

diff --git a/vm/src/builtins/bytearray.rs b/vm/src/builtins/bytearray.rs
@@ -328,7 +328,7 @@ impl PyByteArray {
 
     #[pyclassmethod]
     fn fromhex(cls: PyTypeRef, string: PyStrRef, vm: &VirtualMachine) -> PyResult {
-        let bytes = PyBytesInner::fromhex(string.as_str(), vm)?;
+        let bytes = PyBytesInner::fromhex(string.as_bytes(), vm)?;
         let bytes = vm.ctx.new_bytes(bytes);
         let args = vec![bytes.into()].into();
         PyType::call(&cls, args, vm)

diff --git a/vm/src/builtins/bytes.rs b/vm/src/builtins/bytes.rs
@@ -264,7 +264,7 @@ impl PyBytes {
 
     #[pyclassmethod]
     fn fromhex(cls: PyTypeRef, string: PyStrRef, vm: &VirtualMachine) -> PyResult {
-        let bytes = PyBytesInner::fromhex(string.as_str(), vm)?;
+        let bytes = PyBytesInner::fromhex(string.as_bytes(), vm)?;
         let bytes = vm.ctx.new_bytes(bytes).into();
         PyType::call(&cls, vec![bytes].into(), vm)
     }

diff --git a/vm/src/builtins/function.rs b/vm/src/builtins/function.rs
@@ -859,10 +859,13 @@ impl Representable for PyBoundMethod {
                 vm.get_attribute_opt(zelf.function.clone(), "__name__")?
             };
         let func_name: Option<PyStrRef> = func_name.and_then(|o| o.downcast().ok());
+        let formatted_func_name = match func_name {
+            Some(name) => name.to_string(),
+            None => "?".to_string(),
+        };
+        let object_repr = zelf.object.repr(vm)?;
         Ok(format!(
-            "<bound method {} of {}>",
-            func_name.as_ref().map_or("?", |s| s.as_str()),
-            &zelf.object.repr(vm)?.as_str(),
+            "<bound method {formatted_func_name} of {object_repr}>",
         ))
     }
 }

diff --git a/vm/src/builtins/genericalias.rs b/vm/src/builtins/genericalias.rs
@@ -122,16 +122,16 @@ impl PyGenericAlias {
                     .get_attribute_opt(obj.clone(), identifier!(vm, __args__))?
                     .is_some()
             {
-                return Ok(obj.repr(vm)?.as_str().to_string());
+                return Ok(obj.repr(vm)?.to_string());
             }
 
             match (
                 vm.get_attribute_opt(obj.clone(), identifier!(vm, __qualname__))?
-                    .and_then(|o| o.downcast_ref::<PyStr>().map(|n| n.as_str().to_string())),
+                    .and_then(|o| o.downcast_ref::<PyStr>().map(|n| n.to_string())),
                 vm.get_attribute_opt(obj.clone(), identifier!(vm, __module__))?
-                    .and_then(|o| o.downcast_ref::<PyStr>().map(|m| m.as_str().to_string())),
+                    .and_then(|o| o.downcast_ref::<PyStr>().map(|m| m.to_string())),
             ) {
-                (None, _) | (_, None) => Ok(obj.repr(vm)?.as_str().to_string()),
+                (None, _) | (_, None) => Ok(obj.repr(vm)?.to_string()),
                 (Some(qualname), Some(module)) => Ok(if module == "builtins" {
                     qualname
                 } else {

diff --git a/vm/src/builtins/union.rs b/vm/src/builtins/union.rs
@@ -59,16 +59,16 @@ impl PyUnion {
                     .get_attribute_opt(obj.clone(), identifier!(vm, __args__))?
                     .is_some()
             {
-                return Ok(obj.repr(vm)?.as_str().to_string());
+                return Ok(obj.repr(vm)?.to_string());
             }
 
             match (
                 vm.get_attribute_opt(obj.clone(), identifier!(vm, __qualname__))?
-                    .and_then(|o| o.downcast_ref::<PyStr>().map(|n| n.as_str().to_string())),
+                    .and_then(|o| o.downcast_ref::<PyStr>().map(|n| n.to_string())),
                 vm.get_attribute_opt(obj.clone(), identifier!(vm, __module__))?
-                    .and_then(|o| o.downcast_ref::<PyStr>().map(|m| m.as_str().to_string())),
+                    .and_then(|o| o.downcast_ref::<PyStr>().map(|m| m.to_string())),
             ) {
-                (None, _) | (_, None) => Ok(obj.repr(vm)?.as_str().to_string()),
+                (None, _) | (_, None) => Ok(obj.repr(vm)?.to_string()),
                 (Some(qualname), Some(module)) => Ok(if module == "builtins" {
                     qualname
                 } else {

diff --git a/vm/src/bytes_inner.rs b/vm/src/bytes_inner.rs
@@ -459,11 +459,11 @@ impl PyBytesInner {
         bytes_to_hex(self.elements.as_slice(), sep, bytes_per_sep, vm)
     }
 
-    pub fn fromhex(string: &str, vm: &VirtualMachine) -> PyResult<Vec<u8>> {
-        let mut iter = string.bytes().enumerate();
-        let mut bytes: Vec<u8> = Vec::with_capacity(string.len() / 2);
+    pub fn fromhex(bytes: &[u8], vm: &VirtualMachine) -> PyResult<Vec<u8>> {
+        let mut iter = bytes.iter().enumerate();
+        let mut bytes: Vec<u8> = Vec::with_capacity(bytes.len() / 2);
         let i = loop {
-            let (i, b) = match iter.next() {
+            let (i, &b) = match iter.next() {
                 Some(val) => val,
                 None => {
                     return Ok(bytes);

diff --git a/vm/src/intern.rs b/vm/src/intern.rs
@@ -128,10 +128,7 @@ impl CachedPyStrRef {
     }
 }
 
-pub struct PyInterned<T>
-where
-    T: PyPayload,
-{
+pub struct PyInterned<T> {
     inner: Py<T>,
 }
 
@@ -173,14 +170,14 @@ impl<T: PyPayload> std::hash::Hash for PyInterned<T> {
     }
 }
 
-impl<T: PyPayload> AsRef<Py<T>> for PyInterned<T> {
+impl<T> AsRef<Py<T>> for PyInterned<T> {
     #[inline(always)]
     fn as_ref(&self) -> &Py<T> {
         &self.inner
     }
 }
 
-impl<T: PyPayload> Deref for PyInterned<T> {
+impl<T> Deref for PyInterned<T> {
     type Target = Py<T>;
     #[inline(always)]
     fn deref(&self) -> &Self::Target {
@@ -197,7 +194,7 @@ impl<T: PyPayload> PartialEq for PyInterned<T> {
 
 impl<T: PyPayload> Eq for PyInterned<T> {}
 
-impl<T: PyPayload + std::fmt::Debug> std::fmt::Debug for PyInterned<T> {
+impl<T: std::fmt::Debug + PyPayload> std::fmt::Debug for PyInterned<T> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         std::fmt::Debug::fmt(&**self, f)?;
         write!(f, "@{:p}", self.as_ptr())

diff --git a/vm/src/object/core.rs b/vm/src/object/core.rs
@@ -633,6 +633,7 @@ impl PyObject {
         self.weak_ref_list().map(|wrl| wrl.get_weak_references())
     }
 
+    #[deprecated(note = "use downcastable instead")]
     #[inline(always)]
     pub fn payload_is<T: PyObjectPayload>(&self) -> bool {
         self.0.typeid == T::payload_type_id()
@@ -642,6 +643,7 @@ impl PyObject {
     ///
     /// # Safety
     /// The actual payload type must be T.
+    #[deprecated(note = "use downcast_unchecked_ref instead")]
     #[inline(always)]
     pub const unsafe fn payload_unchecked<T: PyObjectPayload>(&self) -> &T {
         // we cast to a PyInner<T> first because we don't know T's exact offset because of
@@ -653,7 +655,9 @@ impl PyObject {
     #[deprecated(note = "use downcast_ref instead")]
     #[inline(always)]
     pub fn payload<T: PyObjectPayload>(&self) -> Option<&T> {
+        #[allow(deprecated)]
         if self.payload_is::<T>() {
+            #[allow(deprecated)]
             Some(unsafe { self.payload_unchecked() })
         } else {
             None
@@ -719,7 +723,7 @@ impl PyObject {
     /// Check if this object can be downcast to T.
     #[inline(always)]
     pub fn downcastable<T: PyObjectPayload>(&self) -> bool {
-        self.payload_is::<T>()
+        self.0.typeid == T::payload_type_id()
     }
 
     /// Attempt to downcast this reference to a subclass.
@@ -899,9 +903,9 @@ impl<T: PyObjectPayload> Py<T> {
         })
     }
 
+    #[inline]
     pub fn payload(&self) -> &T {
-        // SAFETY: we know the payload is T because of the type parameter
-        unsafe { self.as_object().payload_unchecked() }
+        &self.0.payload
     }
 }
 

diff --git a/vm/src/suggestion.rs b/vm/src/suggestion.rs
@@ -26,7 +26,7 @@ pub fn calculate_suggestions<'a>(
 
     for item in dir_iter {
         let item_name = item.downcast_ref::<PyStr>()?;
-        if name.as_str() == item_name.as_str() {
+        if name.as_bytes() == item_name.as_bytes() {
             continue;
         }
         // No more than 1/3 of the characters should need changed
@@ -35,7 +35,7 @@ pub fn calculate_suggestions<'a>(
             suggestion_distance - 1,
         );
         let current_distance =
-            levenshtein_distance(name.as_str(), item_name.as_str(), max_distance);
+            levenshtein_distance(name.as_bytes(), item_name.as_bytes(), max_distance);
         if current_distance > max_distance {
             continue;
         }