PySequence: use usize everywhere

See #1667

src/conversions/array.rs

@@ -60,7 +60,7 @@ mod min_const_generics {
         if seq_len != N {
             return Err(invalid_sequence_length(N, seq_len));
         }
-        array_try_from_fn(|idx| seq.get_item(idx as isize).and_then(PyAny::extract))
+        array_try_from_fn(|idx| seq.get_item(idx).and_then(PyAny::extract))
     }
 
     // TODO use std::array::try_from_fn, if that stabilises:

src/types/sequence.rs

@@ -18,13 +18,12 @@ impl PySequence {
     ///
     /// This is equivalent to the Python expression `len(self)`.
     #[inline]
-    #[allow(clippy::len_without_is_empty)]
-    pub fn len(&self) -> PyResult<isize> {
+    pub fn len(&self) -> PyResult<usize> {
         let v = unsafe { ffi::PySequence_Size(self.as_ptr()) };
         if v == -1 {
             Err(PyErr::api_call_failed(self.py()))
         } else {
-            Ok(v as isize)
+            Ok(v as usize)
         }
     }
 
@@ -53,9 +52,8 @@ impl PySequence {
     /// Returns the result of repeating a sequence object `count` times.
     ///
     /// This is equivalent to the Python expression `self * count`.
-    /// NB: Python accepts negative counts; it returns an empty Sequence.
     #[inline]
-    pub fn repeat(&self, count: isize) -> PyResult<&PySequence> {
+    pub fn repeat(&self, count: usize) -> PyResult<&PySequence> {
         unsafe {
             let ptr = self
                 .py()
@@ -85,9 +83,8 @@ impl PySequence {
     /// Repeats the sequence object `count` times and updates `self`.
     ///
     /// This is equivalent to the Python statement `self *= count`.
-    /// NB: Python accepts negative counts; it empties the Sequence.
     #[inline]
-    pub fn in_place_repeat(&self, count: isize) -> PyResult<()> {
+    pub fn in_place_repeat(&self, count: usize) -> PyResult<()> {
         unsafe {
             let ptr = ffi::PySequence_InPlaceRepeat(self.as_ptr(), count as Py_ssize_t);
             if ptr.is_null() {
@@ -102,7 +99,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python expression `self[index]`.
     #[inline]
-    pub fn get_item(&self, index: isize) -> PyResult<&PyAny> {
+    pub fn get_item(&self, index: usize) -> PyResult<&PyAny> {
         unsafe {
             self.py()
                 .from_owned_ptr_or_err(ffi::PySequence_GetItem(self.as_ptr(), index as Py_ssize_t))
@@ -113,7 +110,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python expression `self[begin:end]`.
     #[inline]
-    pub fn get_slice(&self, begin: isize, end: isize) -> PyResult<&PyAny> {
+    pub fn get_slice(&self, begin: usize, end: usize) -> PyResult<&PyAny> {
         unsafe {
             self.py().from_owned_ptr_or_err(ffi::PySequence_GetSlice(
                 self.as_ptr(),
@@ -127,7 +124,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python statement `self[i] = v`.
     #[inline]
-    pub fn set_item<I>(&self, i: isize, item: I) -> PyResult<()>
+    pub fn set_item<I>(&self, i: usize, item: I) -> PyResult<()>
     where
         I: ToBorrowedObject,
     {
@@ -145,7 +142,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python statement `del self[i]`.
     #[inline]
-    pub fn del_item(&self, i: isize) -> PyResult<()> {
+    pub fn del_item(&self, i: usize) -> PyResult<()> {
         unsafe {
             err::error_on_minusone(
                 self.py(),
@@ -158,7 +155,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python statement `self[i1:i2] = v`.
     #[inline]
-    pub fn set_slice(&self, i1: isize, i2: isize, v: &PyAny) -> PyResult<()> {
+    pub fn set_slice(&self, i1: usize, i2: usize, v: &PyAny) -> PyResult<()> {
         unsafe {
             err::error_on_minusone(
                 self.py(),
@@ -176,7 +173,7 @@ impl PySequence {
     ///
     /// This is equivalent to the Python statement `del self[i1:i2]`.
     #[inline]
-    pub fn del_slice(&self, i1: isize, i2: isize) -> PyResult<()> {
+    pub fn del_slice(&self, i1: usize, i2: usize) -> PyResult<()> {
         unsafe {
             err::error_on_minusone(
                 self.py(),
@@ -404,11 +401,6 @@ mod tests {
             assert_eq!(3, seq.get_item(3).unwrap().extract::<i32>().unwrap());
             assert_eq!(5, seq.get_item(4).unwrap().extract::<i32>().unwrap());
             assert_eq!(8, seq.get_item(5).unwrap().extract::<i32>().unwrap());
-            assert_eq!(8, seq.get_item(-1).unwrap().extract::<i32>().unwrap());
-            assert_eq!(5, seq.get_item(-2).unwrap().extract::<i32>().unwrap());
-            assert_eq!(3, seq.get_item(-3).unwrap().extract::<i32>().unwrap());
-            assert_eq!(2, seq.get_item(-4).unwrap().extract::<i32>().unwrap());
-            assert_eq!(1, seq.get_item(-5).unwrap().extract::<i32>().unwrap());
             assert!(seq.get_item(10).is_err());
         });
     }