From b79a713b5c2e02058d51a24d11813f4d19549508 Mon Sep 17 00:00:00 2001
From: Chunmyong Park <cmpark0126@gmail.com>
Date: Sun, 14 Jun 2020 12:59:12 +0000
Subject: [PATCH] Update IR interpreter

---
 src/ir/interp.rs | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/ir/interp.rs b/src/ir/interp.rs
index 24329e4..9e8a929 100644
--- a/src/ir/interp.rs
+++ b/src/ir/interp.rs
@@ -611,8 +611,8 @@ mod calculator {
         rhs: Value,
     ) -> Result<Value, ()> {
         match (lhs, rhs) {
-            (Value::Undef { .. }, _) => Err(()),
-            (_, Value::Undef { .. }) => Err(()),
+            (Value::Undef { dtype }, _) => Ok(Value::undef(dtype)),
+            (_, Value::Undef { dtype }) => Ok(Value::undef(dtype)),
             (
                 Value::Int {
                     value: lhs,
@@ -688,7 +688,7 @@ mod calculator {
         operand: Value,
     ) -> Result<Value, ()> {
         match operand {
-            Value::Undef { .. } => Err(()),
+            Value::Undef { dtype } => Ok(Value::undef(dtype)),
             Value::Int {
                 value,
                 width,
@@ -741,7 +741,7 @@ mod calculator {
         }
 
         match (value, dtype) {
-            (Value::Undef { .. }, _) => Err(()),
+            (Value::Undef { .. }, dtype) => Ok(Value::undef(dtype)),
             (
                 Value::Int { value, width, .. },
                 Dtype::Int {