int.__[r]floordiv__ to use BigInt.div_floor

youknowone · youknowone · commit cde88028fd9e · 2019-08-13T10:47:19.000+09:00
diff --git a/tests/snippets/ints.py b/tests/snippets/ints.py
@@ -36,7 +36,13 @@
 assert (2).__mul__(1) == 2
 assert (2).__rmul__(1) == 2
 assert (2).__truediv__(1) == 2.0
+with assertRaises(ZeroDivisionError):
+    (2).__truediv__(0)
 assert (2).__rtruediv__(1) == 0.5
+assert (-2).__floordiv__(3) == -1
+with assertRaises(ZeroDivisionError):
+    (2).__floordiv__(0)
+assert (-3).__rfloordiv__(2) == -1
 assert (-2).__divmod__(3) == (-1, 1)
 with assertRaises(ZeroDivisionError):
     (2).__divmod__(0)
diff --git a/vm/src/obj/objint.rs b/vm/src/obj/objint.rs
@@ -270,11 +270,26 @@ impl PyInt {
     fn floordiv(&self, other: PyObjectRef, vm: &VirtualMachine) -> PyResult {
         if objtype::isinstance(&other, &vm.ctx.int_type()) {
             let v2 = get_value(&other);
-            if *v2 != BigInt::zero() {
-                let modulo = (&self.value % v2 + v2) % v2;
-                Ok(vm.ctx.new_int((&self.value - modulo) / v2))
+            if v2.is_zero() {
+                Err(vm.new_zero_division_error("integer division by zero".to_string()))
             } else {
-                Err(vm.new_zero_division_error("integer floordiv by zero".to_string()))
+                let v1 = &self.value;
+                Ok(vm.ctx.new_int(v1.div_floor(v2)))
+            }
+        } else {
+            Ok(vm.ctx.not_implemented())
+        }
+    }
+
+    #[pymethod(name = "__rfloordiv__")]
+    fn rfloordiv(&self, other: PyObjectRef, vm: &VirtualMachine) -> PyResult {
+        if objtype::isinstance(&other, &vm.ctx.int_type()) {
+            let v2 = &self.value;
+            if v2.is_zero() {
+                Err(vm.new_zero_division_error("integer division by zero".to_string()))
+            } else {
+                let v1 = get_value(&other);
+                Ok(vm.ctx.new_int(v1.div_floor(v2)))
             }
         } else {
             Ok(vm.ctx.not_implemented())
