From bf9b60dce7157e5db3b7e3ed58820b57fc9b80cc Mon Sep 17 00:00:00 2001
From: simomu-github <simomutter@gmail.com>
Date: Thu, 22 Sep 2022 22:45:58 +0900
Subject: [PATCH] Fix computation sequence

---
 instructions.go      | 50 ++++++++++++++++++++++----------------------
 instructions_test.go |  7 ++++---
 2 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/instructions.go b/instructions.go
index e093894..49a29a6 100644
--- a/instructions.go
+++ b/instructions.go
@@ -63,16 +63,16 @@ func (d Discard) Execute(executor *Executor) error {
 type Addition struct{}
 
 func (a Addition) Execute(executor *Executor) error {
-	lhs, errLhs := executor.Pop()
-	if errLhs != nil {
-		return errLhs
-	}
-
 	rhs, errRhs := executor.Pop()
 	if errRhs != nil {
 		return errRhs
 	}
 
+	lhs, errLhs := executor.Pop()
+	if errLhs != nil {
+		return errLhs
+	}
+
 	executor.Push(lhs + rhs)
 
 	return nil
@@ -81,16 +81,16 @@ func (a Addition) Execute(executor *Executor) error {
 type Subtraction struct{}
 
 func (s Subtraction) Execute(executor *Executor) error {
-	lhs, errLhs := executor.Pop()
-	if errLhs != nil {
-		return errLhs
-	}
-
 	rhs, errRhs := executor.Pop()
 	if errRhs != nil {
 		return errRhs
 	}
 
+	lhs, errLhs := executor.Pop()
+	if errLhs != nil {
+		return errLhs
+	}
+
 	executor.Push(lhs - rhs)
 
 	return nil
@@ -99,16 +99,16 @@ func (s Subtraction) Execute(executor *Executor) error {
 type Multiplication struct{}
 
 func (m Multiplication) Execute(executor *Executor) error {
-	lhs, errLhs := executor.Pop()
-	if errLhs != nil {
-		return errLhs
-	}
-
 	rhs, errRhs := executor.Pop()
 	if errRhs != nil {
 		return errRhs
 	}
 
+	lhs, errLhs := executor.Pop()
+	if errLhs != nil {
+		return errLhs
+	}
+
 	executor.Push(lhs * rhs)
 
 	return nil
@@ -117,16 +117,16 @@ func (m Multiplication) Execute(executor *Executor) error {
 type Division struct{}
 
 func (d Division) Execute(executor *Executor) error {
-	lhs, errLhs := executor.Pop()
-	if errLhs != nil {
-		return errLhs
-	}
-
 	rhs, errRhs := executor.Pop()
 	if errRhs != nil {
 		return errRhs
 	}
 
+	lhs, errLhs := executor.Pop()
+	if errLhs != nil {
+		return errLhs
+	}
+
 	executor.Push(lhs / rhs)
 
 	return nil
@@ -135,16 +135,16 @@ func (d Division) Execute(executor *Executor) error {
 type Modulo struct{}
 
 func (m Modulo) Execute(executor *Executor) error {
-	lhs, errLhs := executor.Pop()
-	if errLhs != nil {
-		return errLhs
-	}
-
 	rhs, errRhs := executor.Pop()
 	if errRhs != nil {
 		return errRhs
 	}
 
+	lhs, errLhs := executor.Pop()
+	if errLhs != nil {
+		return errLhs
+	}
+
 	executor.Push(lhs % rhs)
 
 	return nil
diff --git a/instructions_test.go b/instructions_test.go
index 850eaf1..1e44450 100644
--- a/instructions_test.go
+++ b/instructions_test.go
@@ -1,8 +1,9 @@
 package whitespace_go
 
 import (
-	"github.com/stretchr/testify/assert"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func newExecutor() *Executor {
@@ -63,7 +64,7 @@ func TestAddition(t *testing.T) {
 
 func TestSubtraction(t *testing.T) {
 	executor := newExecutor()
-	executor.stack = []int{1, 2}
+	executor.stack = []int{2, 1}
 
 	subtraction := Subtraction{}
 	subtraction.Execute(executor)
@@ -93,7 +94,7 @@ func TestDivision(t *testing.T) {
 
 func TestModulo(t *testing.T) {
 	executor := newExecutor()
-	executor.stack = []int{3, 5}
+	executor.stack = []int{5, 3}
 
 	modulo := Modulo{}
 	modulo.Execute(executor)