From d3bd49511fe2003f5b0916d9a74152d6fa1b7e2d Mon Sep 17 00:00:00 2001
From: drew <drew@drewolson.org>
Date: Fri, 8 Dec 2023 11:29:28 +0800
Subject: [PATCH] No ppx let for lists

---
 lib/year2023/day07.ml | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/lib/year2023/day07.ml b/lib/year2023/day07.ml
index 7421df8..03aa475 100644
--- a/lib/year2023/day07.ml
+++ b/lib/year2023/day07.ml
@@ -86,12 +86,10 @@ let hand_type hand =
 let rec expand = function
   | [] -> [ [] ]
   | Jack :: rest ->
-    let%bind.List c = all_of_card
-    and h = expand rest in
-    if equal_card c Jack then [] else [ c :: h ]
-  | c :: rest ->
-    let%map.List hand = expand rest in
-    c :: hand
+    List.concat_map all_of_card ~f:(function
+      | Jack -> []
+      | c -> List.map (expand rest) ~f:(List.cons c))
+  | c :: rest -> List.map (expand rest) ~f:(List.cons c)
 ;;
 
 let hand_type' hand =