From fcc6635b1f931cce994506fe82eaa50fd84eb6fd Mon Sep 17 00:00:00 2001
From: Jack Park <xarus01@gmail.com>
Date: Fri, 18 Oct 2019 06:50:46 +0700
Subject: [PATCH] Implemented range.__reduce__

---
 tests/snippets/builtin_range.py |  6 ++++++
 vm/src/obj/objrange.rs          | 16 ++++++++++++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/tests/snippets/builtin_range.py b/tests/snippets/builtin_range.py
index e0918bd3f..6bd279c71 100644
--- a/tests/snippets/builtin_range.py
+++ b/tests/snippets/builtin_range.py
@@ -102,6 +102,12 @@ assert list(reversed(range(5))) == [4, 3, 2, 1, 0]
 assert list(reversed(range(5, 0, -1))) == [1, 2, 3, 4, 5]
 assert list(reversed(range(1,10,5))) == [6, 1]
 
+# __reduce__
+assert range(10).__reduce__()[0] == range
+assert range(10).__reduce__()[1] == (0, 10, 1)
+assert range(10, 1, -2).__reduce__()[0] == range
+assert range(10, 1, -2).__reduce__()[1] == (10, 1, -2)
+
 # range retains the original int refs
 i = 2**64
 assert range(i).stop is i
diff --git a/vm/src/obj/objrange.rs b/vm/src/obj/objrange.rs
index e71d03255..3b7ffee1f 100644
--- a/vm/src/obj/objrange.rs
+++ b/vm/src/obj/objrange.rs
@@ -7,14 +7,16 @@ use num_traits::{One, Signed, Zero};
 use crate::function::{OptionalArg, PyFuncArgs};
 use crate::pyhash;
 use crate::pyobject::{
-    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject, TypeProtocol,
+    PyClassImpl, PyContext, PyObjectRef, PyRef, PyResult, PyValue, TryFromObject, TypeProtocol, IntoPyObject
 };
 use crate::vm::VirtualMachine;
 
 use super::objint::{PyInt, PyIntRef};
 use super::objiter;
 use super::objslice::{PySlice, PySliceRef};
-use super::objtype::{self, PyClassRef};
+use super::objtype::{self, PyClassRef, PyClass};
+use super::objtuple::{PyTuple, PyTupleRef};
+use super::objsequence::{get_elements_tuple};
 
 /// range(stop) -> range object
 /// range(start, stop[, step]) -> range object
@@ -286,6 +288,16 @@ impl PyRange {
         Ok(vm.ctx.not_implemented())
     }
 
+    #[pymethod(name = "__reduce__")]
+    fn reduce(&self, vm: &VirtualMachine) -> (PyClassRef, PyTuple) {
+        let range_paramters: Vec<PyObjectRef> = vec![&self.start, &self.stop, &self.step]
+            .iter()
+            .map(|x| x.as_object().clone())
+            .collect();
+        let range_paramters_tuple = PyTuple::from(range_paramters);
+        (vm.ctx.range_type(), range_paramters_tuple)
+    }
+
     #[pymethod(name = "index")]
     fn index(&self, needle: PyObjectRef, vm: &VirtualMachine) -> PyResult<PyInt> {
         if let Ok(int) = needle.downcast::<PyInt>() {