From 039cc128527cef83c8f2c48d17df978ff991ec54 Mon Sep 17 00:00:00 2001
From: Jeong YunWon <jeong@youknowone.org>
Date: Sun, 11 Aug 2019 22:13:04 +0900
Subject: [PATCH] int.__[r]floordiv__ to use BigInt.div_floor

---
 tests/snippets/ints.py |  6 ++++++
 vm/src/obj/objint.rs   | 33 +++++++++++++++++++++++----------
 2 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/tests/snippets/ints.py b/tests/snippets/ints.py
index 40f2610f9..d05848361 100644
--- a/tests/snippets/ints.py
+++ b/tests/snippets/ints.py
@@ -36,7 +36,13 @@ assert (2).__rsub__(1) == -1
 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
index ad9b5fa11..847ba4a15 100644
--- a/vm/src/obj/objint.rs
+++ b/vm/src/obj/objint.rs
@@ -139,10 +139,18 @@ 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() {
-        Ok(vm.ctx.new_int(&int1.value % &int2.value))
-    } else {
+    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 {
+        Ok(vm.ctx.new_int(int1.value.div_floor(&int2.value)))
     }
 }
 
@@ -280,13 +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())
         }