Remove special case for None payload from boolval.

tests/snippets/bools.py

@@ -16,6 +16,9 @@ assert bool() == False
 assert bool(1) == True
 assert bool({}) == False
 
+assert bool(NotImplemented) == True
+assert bool(...) == True
+
 if not 1:
     raise BaseException
 

vm/src/obj/objbool.rs

@@ -13,7 +13,7 @@ impl IntoPyObject for bool {
     }
 }
 
-pub fn boolval(vm: &mut VirtualMachine, obj: PyObjectRef) -> Result<bool, PyObjectRef> {
+pub fn boolval(vm: &mut VirtualMachine, obj: PyObjectRef) -> PyResult<bool> {
     if let Some(s) = obj.payload::<PyString>() {
         return Ok(!s.value.is_empty());
     }
@@ -24,7 +24,6 @@ pub fn boolval(vm: &mut VirtualMachine, obj: PyObjectRef) -> Result<bool, PyObje
         PyObjectPayload::Integer { ref value } => !value.is_zero(),
         PyObjectPayload::Sequence { ref elements } => !elements.borrow().is_empty(),
         PyObjectPayload::Dict { ref elements } => !elements.borrow().is_empty(),
-        PyObjectPayload::None { .. } => false,
         _ => {
             if let Ok(f) = vm.get_method(obj.clone(), "__bool__") {
                 let bool_res = vm.invoke(f, PyFuncArgs::default())?;

vm/src/obj/objnone.rs

@@ -5,6 +5,7 @@ pub fn init(context: &PyContext) {
     let none_type = &context.none.typ();
     context.set_attr(&none_type, "__new__", context.new_rustfunc(none_new));
     context.set_attr(&none_type, "__repr__", context.new_rustfunc(none_repr));
+    context.set_attr(&none_type, "__bool__", context.new_rustfunc(none_bool));
 }
 
 fn none_new(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
@@ -20,3 +21,8 @@ fn none_repr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(_zelf, Some(vm.ctx.none().typ()))]);
     Ok(vm.ctx.new_str("None".to_string()))
 }
+
+fn none_bool(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
+    arg_check!(vm, args, required = [(_zelf, Some(vm.ctx.none().typ()))]);
+    Ok(vm.ctx.new_bool(false))
+}