From 61e7cd7ccf8511558b79d8d0eceb6fa782c10d6b Mon Sep 17 00:00:00 2001
From: Lukasz Czajka <lukasz@heliax.dev>
Date: Wed, 6 Nov 2024 18:23:35 +0100
Subject: [PATCH 1/3] add new modules to index.juvix

---
 index.juvix | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/index.juvix b/index.juvix
index b5d09be2..7b307b9a 100644
--- a/index.juvix
+++ b/index.juvix
@@ -10,8 +10,18 @@ Compiler: http://github.com/anoma/juvix
 module index;
 
 import Stdlib.Prelude;
-import Stdlib.Data.Nat.Ord;
-import Stdlib.Data.Int.Ord;
-import Stdlib.Data.String.Ord;
 
+import Stdlib.Data.BinaryTree;
+import Stdlib.Data.Set;
+import Stdlib.Data.Map;
+import Stdlib.Data.UnbalancedSet;
+import Stdlib.Data.Queue;
+import Stdlib.Data.Tree;
+
+import Stdlib.Cairo.Ec;
 import Stdlib.Cairo.Poseidon;
+import Stdlib.Cairo.Pedersen;
+
+import Stdlib.Debug;
+
+import Stdlib.Extra.Gcd;

From a567cf1722488a441dad94230e7aac7e53353e6e Mon Sep 17 00:00:00 2001
From: mariari <mariari@protonmail.com>
Date: Thu, 7 Nov 2024 13:17:35 +0800
Subject: [PATCH 2/3] Add a maybe head function

The naming on this is probably bad, I'd assume `head` would return
Maybe, and you'd have a headDefault or something for a default head
---
 Stdlib/Data/List/Base.juvix | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Stdlib/Data/List/Base.juvix b/Stdlib/Data/List/Base.juvix
index bc8d0900..589836ff 100644
--- a/Stdlib/Data/List/Base.juvix
+++ b/Stdlib/Data/List/Base.juvix
@@ -165,6 +165,11 @@ head {A} (defaultValue : A) (list : List A) : A :=
     | x :: _ := x
     | nil := defaultValue;
 
+--- 𝒪(1). Grabs the first element of a ;List;
+headMaybe {A} : List A -> Maybe A
+  | (x :: _) := just x
+  | nil := nothing;
+
 syntax iterator any {init := 0; range := 1};
 
 --- 𝒪(𝓃). Returns ;true; if at least one element of the ;List; satisfies the predicate.

From 386b38e483b4bc8d9d543fc4b8a16f2e66fdad12 Mon Sep 17 00:00:00 2001
From: mariari <mariari@protonmail.com>
Date: Thu, 7 Nov 2024 15:18:59 +0800
Subject: [PATCH 3/3] Write the nth function

---
 Stdlib/Data/List/Base.juvix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Stdlib/Data/List/Base.juvix b/Stdlib/Data/List/Base.juvix
index 589836ff..4ea06ecd 100644
--- a/Stdlib/Data/List/Base.juvix
+++ b/Stdlib/Data/List/Base.juvix
@@ -96,6 +96,10 @@ drop {A} : (elemsNum : Nat) -> (list : List A) -> List A
   | (suc n) (x :: xs) := drop n xs
   | _ xs := xs;
 
+--- Take the nth value of a ;List;
+nth {A} : Nat -> List A -> Maybe A
+  | n := drop n >> headMaybe;
+
 --- 𝒪(𝓃). Returns a tuple where first element is the
 --- prefix of the given list of length prefixLength and second element is the
 --- remainder of the ;List;.