remove len

RustPython · youknowone · Jan 1, 2026 · Dec 31, 2025 · Dec 31, 2025 · Dec 31, 2025
commit bb18d0c184b6eb9b4dc80a3b25481d03e1c926b2
diff --git a/crates/vm/src/builtins/bool.rs b/crates/vm/src/builtins/bool.rs
@@ -9,7 +9,6 @@ use crate::{
     types::{AsNumber, Constructor, Representable},
 };
 use core::fmt::{Debug, Formatter};
-use malachite_bigint::Sign;
 use num_traits::Zero;
 
 impl ToPyObject for bool {
@@ -50,29 +49,16 @@ impl PyObjectRef {
             return nb_bool(self.as_object().number(), vm);
         }
 
-        // 2. Try sq_length slot
-        if let Some(sq_length) = slots.as_sequence.length.load() {
-            let len = sq_length(self.as_object().sequence_unchecked(), vm)?;
+        // 2. Try mp_length slot (mapping protocol)
+        if let Some(mp_length) = slots.as_mapping.length.load() {
+            let len = mp_length(self.as_object().mapping_unchecked(), vm)?;
             return Ok(len != 0);
         }
 
-        // 3. Fallback for types not yet using slots
-        // TODO: Remove this block when all types implement AsSequence
-        if let Some(method_or_err) = vm.get_method(self, identifier!(vm, __len__)) {
-            let method = method_or_err?;
-            let len_obj = method.call((), vm)?;
-            let int_obj = len_obj.downcast_ref::<PyInt>().ok_or_else(|| {
-                vm.new_type_error(format!(
-                    "'{}' object cannot be interpreted as an integer",
-                    len_obj.class().name()
-                ))
-            })?;
-
-            let len_val = int_obj.as_bigint();
-            if len_val.sign() == Sign::Minus {
-                return Err(vm.new_value_error("__len__() should return >= 0"));
-            }
-            return Ok(!len_val.is_zero());
+        // 3. Try sq_length slot (sequence protocol)
+        if let Some(sq_length) = slots.as_sequence.length.load() {
+            let len = sq_length(self.as_object().sequence_unchecked(), vm)?;
+            return Ok(len != 0);
         }
 
         // 4. Default: objects without __bool__ or __len__ are truthy

diff --git a/crates/vm/src/builtins/bytearray.rs b/crates/vm/src/builtins/bytearray.rs
@@ -206,7 +206,6 @@ impl PyByteArray {
         self.inner().capacity()
     }
 
-    #[pymethod]
     fn __len__(&self) -> usize {
         self.borrow_buf().len()
     }

diff --git a/crates/vm/src/builtins/bytes.rs b/crates/vm/src/builtins/bytes.rs
@@ -205,7 +205,6 @@ impl PyRef<PyBytes> {
 )]
 impl PyBytes {
     #[inline]
-    #[pymethod]
     pub const fn __len__(&self) -> usize {
         self.inner.len()
     }

diff --git a/crates/vm/src/builtins/dict.rs b/crates/vm/src/builtins/dict.rs
@@ -212,7 +212,6 @@ impl PyDict {
         }
     }
 
-    #[pymethod]
     pub fn __len__(&self) -> usize {
         self.entries.len()
     }
@@ -764,7 +763,6 @@ trait DictView: PyPayload + PyClassDef + Iterable + Representable {
     fn dict(&self) -> &Py<PyDict>;
     fn item(vm: &VirtualMachine, key: PyObjectRef, value: PyObjectRef) -> PyObjectRef;
 
-    #[pymethod]
     fn __len__(&self) -> usize {
         self.dict().__len__()
     }

diff --git a/crates/vm/src/builtins/list.rs b/crates/vm/src/builtins/list.rs
@@ -182,7 +182,6 @@ impl PyList {
     }
 
     #[allow(clippy::len_without_is_empty)]
-    #[pymethod]
     pub fn __len__(&self) -> usize {
         self.borrow_vec().len()
     }

diff --git a/crates/vm/src/builtins/mappingproxy.rs b/crates/vm/src/builtins/mappingproxy.rs
@@ -173,7 +173,6 @@ impl PyMappingProxy {
         PyGenericAlias::from_args(cls, args, vm)
     }
 
-    #[pymethod]
     fn __len__(&self, vm: &VirtualMachine) -> PyResult<usize> {
         let obj = self.to_object(vm)?;
         obj.length(vm)
@@ -235,6 +234,7 @@ impl AsMapping for PyMappingProxy {
 impl AsSequence for PyMappingProxy {
     fn as_sequence() -> &'static PySequenceMethods {
         static AS_SEQUENCE: LazyLock<PySequenceMethods> = LazyLock::new(|| PySequenceMethods {
+            length: atomic_func!(|seq, vm| PyMappingProxy::sequence_downcast(seq).__len__(vm)),
             contains: atomic_func!(
                 |seq, target, vm| PyMappingProxy::sequence_downcast(seq)._contains(target, vm)
             ),

diff --git a/crates/vm/src/builtins/memory.rs b/crates/vm/src/builtins/memory.rs
@@ -690,7 +690,6 @@ impl PyMemoryView {
         Err(vm.new_type_error("cannot delete memory"))
     }
 
-    #[pymethod]
     fn __len__(&self, vm: &VirtualMachine) -> PyResult<usize> {
         self.try_not_released(vm)?;
         if self.desc.ndim() == 0 {

diff --git a/crates/vm/src/builtins/tuple.rs b/crates/vm/src/builtins/tuple.rs
@@ -298,7 +298,6 @@ impl PyTuple {
     }
 
     #[inline]
-    #[pymethod]
     pub const fn __len__(&self) -> usize {
         self.elements.len()
     }

diff --git a/crates/vm/src/stdlib/collections.rs b/crates/vm/src/stdlib/collections.rs
@@ -350,7 +350,6 @@ mod _collections {
             Ok(zelf)
         }
 
-        #[pymethod]
         fn __len__(&self) -> usize {
             self.borrow_deque().len()
         }

diff --git a/crates/vm/src/stdlib/ctypes/array.rs b/crates/vm/src/stdlib/ctypes/array.rs
@@ -1087,7 +1087,6 @@ impl PyCArray {
         Ok(())
     }
 
-    #[pymethod]
     fn __len__(zelf: &Py<Self>, _vm: &VirtualMachine) -> usize {
         zelf.class().stg_info_opt().map_or(0, |i| i.length)
     }
-Original file line number
+Diff line change
@@ Expand Up / @@ -1087,7 +1087,6 @@ impl PyCArray { @@
             Ok(())
         }
-        #[pymethod]
         fn __len__(zelf: &Py<Self>, _vm: &VirtualMachine) -> usize {
             zelf.class().stg_info_opt().map_or(0, |i| i.length)
         }
@@ Expand Down @@