Clean-up cases where vm.get_attribute is used for magic-method lookup.

cthulahoops · cthulahoops · commit 3379fdaf3f6e · 2018-11-01T21:00:07.000Z
diff --git a/vm/src/builtins.rs b/vm/src/builtins.rs
@@ -50,8 +50,8 @@ fn dir_object(vm: &mut VirtualMachine, obj: &PyObjectRef) -> PyObjectRef {
 
 fn builtin_abs(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(x, None)]);
-    match vm.get_attribute(x.clone(), &"__abs__") {
-        Ok(attrib) => vm.invoke(attrib, PyFuncArgs::new(vec![], vec![])),
+    match vm.call_method(x, "__abs__", vec![]) {
+        Ok(result) => Ok(result),
         Err(..) => Err(vm.new_type_error("bad operand for abs".to_string())),
     }
 }
@@ -134,8 +134,8 @@ fn builtin_dir(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
 
 fn builtin_divmod(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     arg_check!(vm, args, required = [(x, None), (y, None)]);
-    match vm.get_attribute(x.clone(), &"__divmod__") {
-        Ok(attrib) => vm.invoke(attrib, PyFuncArgs::new(vec![y.clone()], vec![])),
+    match vm.call_method(&x.clone(), "__divmod__", vec![y.clone()]) {
+        Ok(result) => Ok(result),
         Err(..) => Err(vm.new_type_error("unsupported operand type(s) for divmod".to_string())),
     }
 }
@@ -218,11 +218,7 @@ fn builtin_getattr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         args,
         required = [(obj, None), (attr, Some(vm.ctx.str_type()))]
     );
-    if let PyObjectKind::String { ref value } = attr.borrow().kind {
-        vm.get_attribute(obj.clone(), value)
-    } else {
-        panic!("argument checking failure: attr not string")
-    }
+    vm.call_method(&obj.clone(), "__getattribute__", vec![attr.clone()])
 }
 
 // builtin_globals
@@ -233,15 +229,11 @@ fn builtin_hasattr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         args,
         required = [(obj, None), (attr, Some(vm.ctx.str_type()))]
     );
-    if let PyObjectKind::String { ref value } = attr.borrow().kind {
-        let has_attr = match vm.get_attribute(obj.clone(), value) {
-            Ok(..) => true,
-            Err(..) => false,
-        };
-        Ok(vm.context().new_bool(has_attr))
-    } else {
-        panic!("argument checking failure: attr not string")
-    }
+    let has_attr = match vm.call_method(&obj.clone(), "__getattribute__", vec![attr.clone()]) {
+        Ok(..) => true,
+        Err(..) => false,
+    };
+    Ok(vm.context().new_bool(has_attr))
 }
 
 fn builtin_hash(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
@@ -306,19 +298,7 @@ fn builtin_len(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
         PyObjectKind::Tuple { ref elements } => {
             Ok(vm.context().new_int(elements.len().to_bigint().unwrap()))
         }
-        _ => {
-            let len_method_name = "__len__".to_string();
-            match vm.get_attribute(obj.clone(), &len_method_name) {
-                Ok(value) => vm.invoke(value, PyFuncArgs::default()),
-                Err(..) => Err(vm.context().new_str(
-                    format!(
-                        "TypeError: object of this {:?} type has no method {:?}",
-                        obj, len_method_name
-                    )
-                    .to_string(),
-                )),
-            }
-        }
+        _ => vm.call_method(&obj.clone(), "__len__", vec![]),
     }
 }
 
diff --git a/vm/src/obj/objtype.rs b/vm/src/obj/objtype.rs
@@ -300,11 +300,6 @@ fn type_repr(vm: &mut VirtualMachine, args: PyFuncArgs) -> PyResult {
     Ok(vm.new_str(format!("<class '{}'>", type_name)))
 }
 
-pub fn call(vm: &mut VirtualMachine, typ: PyObjectRef, args: PyFuncArgs) -> PyResult {
-    let function = vm.get_attribute(typ, &String::from("__call__"))?;
-    vm.invoke(function, args)
-}
-
 #[cfg(test)]
 mod tests {
     use super::{linearise_mro, new};
