1 files changed, 12 insertions, 4 deletions
diff --git a/aoc-2020-gleam/src/ext/setx.gleam b/aoc-2020-gleam/src/ext/setx.gleam
index 68d185a..6df9256 100644
--- a/aoc-2020-gleam/src/ext/setx.gleam
+++ b/aoc-2020-gleam/src/ext/setx.gleam
@@ -3,16 +3,24 @@ import gleam/set.{type Set}
 import gleam/iterator as iter
 import ext/iteratorx as iterx
 
-pub fn count(set: Set(a), satisfying predicate: fn(a) -> Bool) -> Int {
-  set
+pub fn count(s: Set(a), satisfying predicate: fn(a) -> Bool) -> Int {
+  s
   |> set.to_list
   |> iter.from_list
   |> iterx.count(satisfying: predicate)
 }
 
-pub fn map(set: Set(a), with fun: fn(a) -> b) -> Set(b) {
-  set
+pub fn map(s: Set(a), with fun: fn(a) -> b) -> Set(b) {
+  s
   |> set.to_list
   |> list.map(with: fun)
   |> set.from_list
 }
+
+pub fn toggle(in s: Set(a), this value: a) -> Set(a) {
+  s
+  |> case set.contains(in: s, this: value) {
+    True -> set.delete(from: _, this: value)
+    False -> set.insert(into: _, this: value)
+  }
+}