From 242ac5f0f9f11a90b5b15bbfde3ac808e51f3922 Mon Sep 17 00:00:00 2001
From: eul94458 <62548460+eul94458@users.noreply.github.com>
Date: Thu, 9 Feb 2023 16:48:31 +0900
Subject: [PATCH 1/2] Improving reversi()

---
 docs/decoupled.md | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/docs/decoupled.md b/docs/decoupled.md
index 419beb0..708eace 100644
--- a/docs/decoupled.md
+++ b/docs/decoupled.md
@@ -176,12 +176,28 @@ def reversi(arr):
 def reversi(arr):
     """Reverses a list."""
     reved = []
-    for i in range(len(arr)):
-        reved.append(arr[len(arr) - 1 - i])
+    for i in reversed(range(len(arr)):
+        reved.append(arr[i])
     return reved
 ```
 ````
 
+````{tabbed} Even better code using list indexing
+```
+def reversi(arr):
+    """Reverses a list."""
+    return arr[::-1]
+```
+````
+
+````{tabbed} Even better code version using builtin function
+```
+def reversi(arr):
+    """Reverses a list."""
+    return list(reversed(arr))
+```
+````
+
 Functions with side effects can be hard to reason about: you often need to understand their internals and state in order to use them properly. They're also harder to test. **Not every function with side effects is problematic, however**. My pragmatic advice is to first learn to spot and understand pure functions. Then organize your code so that many functions are pure, and those that are not are well-behaved.
 
 ```{figure} figures/pure-impure.svg

From 2f747b9b34f9f9aba3d36c695653f230a577551b Mon Sep 17 00:00:00 2001
From: eul94458 <62548460+eul94458@users.noreply.github.com>
Date: Thu, 9 Feb 2023 17:00:41 +0900
Subject: [PATCH 2/2] reversed(range(len(arr)))

---
 docs/decoupled.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/decoupled.md b/docs/decoupled.md
index 708eace..162681f 100644
--- a/docs/decoupled.md
+++ b/docs/decoupled.md
@@ -176,7 +176,7 @@ def reversi(arr):
 def reversi(arr):
     """Reverses a list."""
     reved = []
-    for i in reversed(range(len(arr)):
+    for i in reversed(range(len(arr))):
         reved.append(arr[i])
     return reved
 ```
@@ -190,7 +190,7 @@ def reversi(arr):
 ```
 ````
 
-````{tabbed} Even better code version using builtin function
+````{tabbed} Even better code version using built-in functions
 ```
 def reversi(arr):
     """Reverses a list."""