Cleanup some direct magic method definitions (#7441)

* Migrate direct __repr__ definitions to Representable trait

Move legacy #[pymethod] __repr__ to impl Representable for:
- PySSLContext, PySSLSocket (ssl.rs)
- BufferedReader, BufferedWriter, BufferedRandom (_io.rs)

Enable __repr__ guard in derive to prevent future direct definitions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Migrate direct __del__ definition to Destructor trait for PySocket

Move #[pymethod] __del__ to impl Destructor for PySocket.
Preserves ResourceWarning emission and close behavior.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Remove redundant __iter__ pymethods from PyFuture and PyTask

Both types already have impl Iterable, so the direct #[pymethod]
__iter__ definitions were duplicates. Enable __iter__/__next__
guards in derive to prevent future direct definitions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Enable derive guards for __get__/__set__/__delete__ descriptor methods

All concrete types already use GetDescriptor/SetDescriptor traits.
Activate the compile-time guard to prevent future direct definitions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Enable derive guards for AsMapping/AsSequence slot methods

Remove redundant #[pymethod(name = "__len__")] from PyStr
(already provided via AsMapping/AsSequence trait impls).

Enable compile-time guards for __len__, __contains__, __getitem__,
__setitem__, __delitem__ to prevent future direct definitions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/derive-impl/src/pyclass.rs

@@ -917,7 +917,7 @@ where
                 ("__new__", "Constructor"),
                 ("__init__", "Initializer"),
                 // Representable trait
-                // ("__repr__", "Representable"),
+                ("__repr__", "Representable"),
                 // ("__str__", "???"), // allow __str__
                 // Hashable trait
                 ("__hash__", "Hashable"),
@@ -927,9 +927,9 @@ where
                 // NOTE: __getattribute__, __setattr__, __delattr__ are intentionally NOT forbidden
                 // because they need pymethod for subclass override mechanism to work properly.
                 // GetDescriptor/SetDescriptor traits
-                // ("__get__", "GetDescriptor"),
-                // ("__set__", "SetDescriptor"),
-                // ("__delete__", "SetDescriptor"),
+                ("__get__", "GetDescriptor"),
+                ("__set__", "SetDescriptor"),
+                ("__delete__", "SetDescriptor"),
                 // AsNumber trait
                 ("__add__", "AsNumber"),
                 ("__radd__", "AsNumber"),
@@ -981,15 +981,15 @@ where
                 ("__index__", "AsNumber"),
                 ("__bool__", "AsNumber"),
                 // AsSequence trait
-                // ("__len__", "AsSequence (or AsMapping)"),
-                // ("__contains__", "AsSequence"),
+                ("__len__", "AsSequence (or AsMapping)"),
+                ("__contains__", "AsSequence"),
                 // AsMapping trait
-                // ("__getitem__", "AsMapping (or AsSequence)"),
-                // ("__setitem__", "AsMapping (or AsSequence)"),
-                // ("__delitem__", "AsMapping (or AsSequence)"),
-                // IterNext trait
-                // ("__iter__", "IterNext"),
-                // ("__next__", "IterNext"),
+                ("__getitem__", "AsMapping (or AsSequence)"),
+                ("__setitem__", "AsMapping (or AsSequence)"),
+                ("__delitem__", "AsMapping (or AsSequence)"),
+                // Iterable/IterNext traits
+                ("__iter__", "Iterable"),
+                ("__next__", "IterNext"),
                 // Comparable trait
                 ("__eq__", "Comparable"),
                 ("__ne__", "Comparable"),

crates/stdlib/src/_asyncio.rs

@@ -764,11 +764,6 @@ pub(crate) mod _asyncio {
             Ok(())
         }
 
-        #[pymethod]
-        fn __iter__(zelf: PyRef<Self>, vm: &VirtualMachine) -> PyResult<PyFutureIter> {
-            Self::__await__(zelf, vm)
-        }
-
         #[pymethod]
         fn __await__(zelf: PyRef<Self>, _vm: &VirtualMachine) -> PyResult<PyFutureIter> {
             Ok(PyFutureIter {
@@ -1828,13 +1823,6 @@ pub(crate) mod _asyncio {
             }
         }
 
-        #[pymethod]
-        fn __iter__(zelf: PyRef<Self>, _vm: &VirtualMachine) -> PyResult<PyFutureIter> {
-            Ok(PyFutureIter {
-                future: PyRwLock::new(Some(zelf.into())),
-            })
-        }
-
         #[pymethod]
         fn __await__(zelf: PyRef<Self>, _vm: &VirtualMachine) -> PyResult<PyFutureIter> {
             Ok(PyFutureIter {

crates/stdlib/src/socket.rs

@@ -20,7 +20,7 @@ mod _socket {
             ArgBytesLike, ArgIntoFloat, ArgMemoryBuffer, ArgStrOrBytesLike, Either, FsPath,
             OptionalArg, OptionalOption,
         },
-        types::{Constructor, DefaultConstructor, Initializer, Representable},
+        types::{Constructor, DefaultConstructor, Destructor, Initializer, Representable},
         utils::ToCString,
     };
 
@@ -1417,7 +1417,44 @@ mod _socket {
         }
     }
 
-    #[pyclass(with(Constructor, Initializer, Representable), flags(BASETYPE))]
+    impl Destructor for PySocket {
+        fn del(zelf: &Py<Self>, vm: &VirtualMachine) -> PyResult<()> {
+            // Emit ResourceWarning if socket is still open
+            if zelf.sock.read().is_some() {
+                let laddr = if let Ok(sock) = zelf.sock()
+                    && let Ok(addr) = sock.local_addr()
+                    && let Ok(repr) = get_addr_tuple(&addr, vm).repr(vm)
+                {
+                    format!(", laddr={}", repr.as_wtf8())
+                } else {
+                    String::new()
+                };
+
+                let msg = format!(
+                    "unclosed <socket.socket fd={}, family={}, type={}, proto={}{}>",
+                    zelf.fileno(),
+                    zelf.family.load(),
+                    zelf.kind.load(),
+                    zelf.proto.load(),
+                    laddr
+                );
+                let _ = crate::vm::warn::warn(
+                    vm.ctx.new_str(msg).into(),
+                    Some(vm.ctx.exceptions.resource_warning.to_owned()),
+                    1,
+                    None,
+                    vm,
+                );
+            }
+            let _ = zelf.close();
+            Ok(())
+        }
+    }
+
+    #[pyclass(
+        with(Constructor, Initializer, Representable, Destructor),
+        flags(BASETYPE)
+    )]
     impl PySocket {
         fn _init(
             zelf: PyRef<Self>,
@@ -2139,38 +2176,6 @@ mod _socket {
             Ok(())
         }
 
-        #[pymethod]
-        fn __del__(&self, vm: &VirtualMachine) {
-            // Emit ResourceWarning if socket is still open
-            if self.sock.read().is_some() {
-                let laddr = if let Ok(sock) = self.sock()
-                    && let Ok(addr) = sock.local_addr()
-                    && let Ok(repr) = get_addr_tuple(&addr, vm).repr(vm)
-                {
-                    format!(", laddr={}", repr.as_wtf8())
-                } else {
-                    String::new()
-                };
-
-                let msg = format!(
-                    "unclosed <socket.socket fd={}, family={}, type={}, proto={}{}>",
-                    self.fileno(),
-                    self.family.load(),
-                    self.kind.load(),
-                    self.proto.load(),
-                    laddr
-                );
-                let _ = crate::vm::warn::warn(
-                    vm.ctx.new_str(msg).into(),
-                    Some(vm.ctx.exceptions.resource_warning.to_owned()),
-                    1,
-                    None,
-                    vm,
-                );
-            }
-            let _ = self.close();
-        }
-
         #[pymethod]
         #[inline]
         fn detach(&self) -> i64 {

crates/stdlib/src/ssl.rs

@@ -857,18 +857,13 @@ mod _ssl {
         binary_form: OptionalArg<bool>,
     }
 
-    #[pyclass(with(Constructor), flags(BASETYPE))]
+    #[pyclass(with(Constructor, Representable), flags(BASETYPE))]
     impl PySSLContext {
         // Helper method to convert DER certificate bytes to Python dict
         fn cert_der_to_dict(&self, vm: &VirtualMachine, cert_der: &[u8]) -> PyResult<PyObjectRef> {
             cert::cert_der_to_dict_helper(vm, cert_der)
         }
 
-        #[pymethod]
-        fn __repr__(&self) -> String {
-            format!("<SSLContext(protocol={})>", self.protocol)
-        }
-
         #[pygetset]
         fn check_hostname(&self) -> bool {
             *self.check_hostname.read()
@@ -2191,6 +2186,13 @@ mod _ssl {
         }
     }
 
+    impl Representable for PySSLContext {
+        #[inline]
+        fn repr_str(zelf: &Py<Self>, _vm: &VirtualMachine) -> PyResult<String> {
+            Ok(format!("<SSLContext(protocol={})>", zelf.protocol))
+        }
+    }
+
     impl Constructor for PySSLContext {
         type Args = (i32,);
 
@@ -2374,7 +2376,7 @@ mod _ssl {
         Completed,       // unwrap() completed successfully
     }
 
-    #[pyclass(with(Constructor), flags(BASETYPE))]
+    #[pyclass(with(Constructor, Representable), flags(BASETYPE))]
     impl PySSLSocket {
         // Check if this is BIO mode
         pub(crate) fn is_bio_mode(&self) -> bool {
@@ -3021,11 +3023,6 @@ mod _ssl {
             }
         }
 
-        #[pymethod]
-        fn __repr__(&self) -> String {
-            "<SSLSocket>".to_string()
-        }
-
         // Helper function to convert Python PROTO_* constants to rustls versions
         fn get_rustls_versions(
             minimum: i32,
@@ -4562,6 +4559,13 @@ mod _ssl {
         }
     }
 
+    impl Representable for PySSLSocket {
+        #[inline]
+        fn repr_str(_zelf: &Py<Self>, _vm: &VirtualMachine) -> PyResult<String> {
+            Ok("<SSLSocket>".to_owned())
+        }
+    }
+
     impl Constructor for PySSLSocket {
         type Args = ();
 

crates/vm/src/builtins/str.rs

@@ -663,7 +663,6 @@ impl PyStr {
         self.data.is_empty()
     }
 
-    #[pymethod(name = "__len__")]
     #[inline]
     pub fn char_len(&self) -> usize {
         self.data.char_len()