mirror of
https://github.com/RustPython/RustPython.git
synced 2026-06-17 01:51:39 +09:00
117 lines
4.1 KiB
Rust
117 lines
4.1 KiB
Rust
use crate::obj::objproperty::PyPropertyRef;
|
|
use crate::obj::objstr::PyStringRef;
|
|
use crate::obj::objtype::{class_get_attr, class_has_attr, PyClassRef};
|
|
use crate::pyobject::{
|
|
IntoPyObject, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject, TypeProtocol,
|
|
};
|
|
use crate::vm::VirtualMachine;
|
|
|
|
#[derive(Debug)]
|
|
pub struct PyNone;
|
|
pub type PyNoneRef = PyRef<PyNone>;
|
|
|
|
impl PyValue for PyNone {
|
|
fn class(vm: &VirtualMachine) -> PyClassRef {
|
|
vm.ctx.none().class()
|
|
}
|
|
}
|
|
|
|
// This allows a built-in function to not return a value, mapping to
|
|
// Python's behavior of returning `None` in this situation.
|
|
impl IntoPyObject for () {
|
|
fn into_pyobject(self, vm: &VirtualMachine) -> PyResult {
|
|
Ok(vm.ctx.none())
|
|
}
|
|
}
|
|
|
|
impl<T: IntoPyObject> IntoPyObject for Option<T> {
|
|
fn into_pyobject(self, vm: &VirtualMachine) -> PyResult {
|
|
match self {
|
|
Some(x) => x.into_pyobject(vm),
|
|
None => Ok(vm.ctx.none()),
|
|
}
|
|
}
|
|
}
|
|
|
|
impl PyNoneRef {
|
|
fn repr(self, _vm: &VirtualMachine) -> PyResult<String> {
|
|
Ok("None".to_string())
|
|
}
|
|
|
|
fn bool(self, _vm: &VirtualMachine) -> PyResult<bool> {
|
|
Ok(false)
|
|
}
|
|
|
|
fn get_attribute(self, name: PyStringRef, vm: &VirtualMachine) -> PyResult {
|
|
trace!("None.__getattribute__({:?}, {:?})", self, name);
|
|
let cls = self.class();
|
|
|
|
// Properties use a comparision with None to determine if they are either invoked by am
|
|
// instance binding or a class binding. But if the object itself is None then this detection
|
|
// won't work. Instead we call a special function on property that bypasses this check, as
|
|
// we are invoking it as a instance binding.
|
|
//
|
|
// In CPython they instead call the slot tp_descr_get with NULL to indicates it's an
|
|
// instance binding.
|
|
// https://github.com/python/cpython/blob/master/Objects/typeobject.c#L3281
|
|
fn call_descriptor(
|
|
descriptor: PyObjectRef,
|
|
get_func: PyObjectRef,
|
|
obj: PyObjectRef,
|
|
cls: PyObjectRef,
|
|
vm: &VirtualMachine,
|
|
) -> PyResult {
|
|
if let Ok(property) = PyPropertyRef::try_from_object(vm, descriptor.clone()) {
|
|
property.instance_binding_get(obj, vm)
|
|
} else {
|
|
vm.invoke(get_func, vec![descriptor, obj, cls])
|
|
}
|
|
}
|
|
|
|
if let Some(attr) = class_get_attr(&cls, &name.value) {
|
|
let attr_class = attr.class();
|
|
if class_has_attr(&attr_class, "__set__") {
|
|
if let Some(get_func) = class_get_attr(&attr_class, "__get__") {
|
|
return call_descriptor(
|
|
attr,
|
|
get_func,
|
|
self.into_object(),
|
|
cls.into_object(),
|
|
vm,
|
|
);
|
|
}
|
|
}
|
|
}
|
|
|
|
// None has no attributes and cannot have attributes set on it.
|
|
// if let Some(obj_attr) = self.as_object().get_attr(&name.value) {
|
|
// Ok(obj_attr)
|
|
// } else
|
|
if let Some(attr) = class_get_attr(&cls, &name.value) {
|
|
let attr_class = attr.class();
|
|
if let Some(get_func) = class_get_attr(&attr_class, "__get__") {
|
|
call_descriptor(attr, get_func, self.into_object(), cls.into_object(), vm)
|
|
} else {
|
|
Ok(attr)
|
|
}
|
|
} else if let Some(getter) = class_get_attr(&cls, "__getattr__") {
|
|
vm.invoke(getter, vec![self.into_object(), name.into_object()])
|
|
} else {
|
|
Err(vm.new_attribute_error(format!("{} has no attribute '{}'", self.as_object(), name)))
|
|
}
|
|
}
|
|
}
|
|
|
|
fn none_new(_: PyClassRef, vm: &VirtualMachine) -> PyNoneRef {
|
|
vm.ctx.none.clone()
|
|
}
|
|
|
|
pub fn init(context: &PyContext) {
|
|
extend_class!(context, &context.none.class(), {
|
|
"__new__" => context.new_rustfunc(none_new),
|
|
"__repr__" => context.new_rustfunc(PyNoneRef::repr),
|
|
"__bool__" => context.new_rustfunc(PyNoneRef::bool),
|
|
"__getattribute__" => context.new_rustfunc(PyNoneRef::get_attribute)
|
|
});
|
|
}
|