Merge pull request RustPython#1239 from youknowone/fix-divmod

Fix int [r]divmod, Add rfloordiv

Author: windelbouwman

tests/snippets/builtin_divmod.py

@@ -3,6 +3,7 @@
 assert divmod(11, 3) == (3, 2)
 assert divmod(8,11) == (0, 8)
 assert divmod(0.873, 0.252) == (3.0, 0.11699999999999999)
+assert divmod(-86340, 86400) == (-1, 60)
 
 assert_raises(ZeroDivisionError, lambda: divmod(5, 0), 'divmod by zero')
 assert_raises(ZeroDivisionError, lambda: divmod(5.0, 0.0), 'divmod by zero')

tests/snippets/ints.py

@@ -36,7 +36,17 @@
 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)
+assert (-3).__rdivmod__(2) == (-1, -1)
 assert (2).__pow__(3) == 8
 assert (10).__pow__(-1) == 0.1
 assert (2).__rpow__(3) == 9

vm/src/obj/objint.rs

@@ -139,10 +139,29 @@ fn inner_pow(int1: &PyInt, int2: &PyInt, vm: &VirtualMachine) -> PyResult {
 }
 
 fn inner_mod(int1: &PyInt, int2: &PyInt, vm: &VirtualMachine) -> PyResult {
-    if int2.value != BigInt::zero() {
+    if int2.value.is_zero() {
+        Err(vm.new_zero_division_error("integer modulo by zero".to_string()))
+    } else {
         Ok(vm.ctx.new_int(&int1.value % &int2.value))
+    }
+}
+
+fn inner_floordiv(int1: &PyInt, int2: &PyInt, vm: &VirtualMachine) -> PyResult {
+    if int2.value.is_zero() {
+        Err(vm.new_zero_division_error("integer division by zero".to_string()))
     } else {
-        Err(vm.new_zero_division_error("integer modulo by zero".to_string()))
+        Ok(vm.ctx.new_int(int1.value.div_floor(&int2.value)))
+    }
+}
+
+fn inner_divmod(int1: &PyInt, int2: &PyInt, vm: &VirtualMachine) -> PyResult {
+    if int2.value.is_zero() {
+        Err(vm.new_zero_division_error("integer division or modulo by zero".to_string()))
+    } else {
+        let (div, modulo) = int1.value.div_mod_floor(&int2.value);
+        Ok(vm
+            .ctx
+            .new_tuple(vec![vm.ctx.new_int(div), vm.ctx.new_int(modulo)]))
     }
 }
 
@@ -269,13 +288,18 @@ impl PyInt {
     #[pymethod(name = "__floordiv__")]
     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))
-            } else {
-                Err(vm.new_zero_division_error("integer floordiv by zero".to_string()))
-            }
+            let other = other.payload::<PyInt>().unwrap();
+            inner_floordiv(self, &other, &vm)
+        } 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 other = other.payload::<PyInt>().unwrap();
+            inner_floordiv(&other, self, &vm)
         } else {
             Ok(vm.ctx.not_implemented())
         }
@@ -397,15 +421,18 @@ impl PyInt {
     #[pymethod(name = "__divmod__")]
     fn divmod(&self, other: PyObjectRef, vm: &VirtualMachine) -> PyResult {
         if objtype::isinstance(&other, &vm.ctx.int_type()) {
-            let v2 = get_value(&other);
-            if *v2 != BigInt::zero() {
-                let (r1, r2) = self.value.div_rem(v2);
-                Ok(vm
-                    .ctx
-                    .new_tuple(vec![vm.ctx.new_int(r1), vm.ctx.new_int(r2)]))
-            } else {
-                Err(vm.new_zero_division_error("integer divmod by zero".to_string()))
-            }
+            let other = other.payload::<PyInt>().unwrap();
+            inner_divmod(self, &other, vm)
+        } else {
+            Ok(vm.ctx.not_implemented())
+        }
+    }
+
+    #[pymethod(name = "__rdivmod__")]
+    fn rdivmod(&self, other: PyObjectRef, vm: &VirtualMachine) -> PyResult {
+        if objtype::isinstance(&other, &vm.ctx.int_type()) {
+            let other = other.payload::<PyInt>().unwrap();
+            inner_divmod(&other, self, vm)
         } else {
             Ok(vm.ctx.not_implemented())
         }