4 files changed, 60 insertions, 36 deletions
diff --git a/aoc-2020-gleam/src/util/hex.gleam b/aoc-2020-gleam/src/util/hex.gleam
index 21db192..070b6e4 100644
--- a/aoc-2020-gleam/src/util/hex.gleam
+++ b/aoc-2020-gleam/src/util/hex.gleam
@@ -1,3 +1,8 @@
+import gleam/bool
+import gleam/list
+import gleam/set.{type Set}
+import ext/setx
+
 pub opaque type Hex {
   Hex(q: Int, r: Int, s: Int)
 }
@@ -19,3 +24,25 @@ pub const ne = Hex(q: 1, r: -1, s: 0)
 pub fn add(a: Hex, b: Hex) -> Hex {
   Hex(q: a.q + b.q, r: a.r + b.r, s: a.s + b.s)
 }
+
+fn directions7() -> Set(Hex) {
+  set.from_list({
+    use q <- list.flat_map([-1, 0, 1])
+    use r <- list.flat_map([-1, 0, 1])
+    use s <- list.flat_map([-1, 0, 1])
+    use <- bool.guard(when: q + r + s != 0, return: [])
+    [Hex(q, r, s)]
+  })
+}
+
+fn directions6() -> Set(Hex) {
+  set.delete(from: directions7(), this: zero)
+}
+
+pub fn neighbours6(h: Hex) -> Set(Hex) {
+  setx.map(directions6(), with: add(h, _))
+}
+
+pub fn neighbours7(h: Hex) -> Set(Hex) {
+  setx.map(directions7(), with: add(h, _))
+}
diff --git a/aoc-2020-gleam/src/util/pos2.gleam b/aoc-2020-gleam/src/util/pos2.gleam
index 3f478ac..976088e 100644
--- a/aoc-2020-gleam/src/util/pos2.gleam
+++ b/aoc-2020-gleam/src/util/pos2.gleam
@@ -1,7 +1,7 @@
 import gleam/int
-import gleam/bool
 import gleam/list
 import gleam/set.{type Set}
+import ext/setx
 
 pub type Pos2 =
   #(Int, Int)
@@ -16,16 +16,18 @@ pub fn y(pos: Pos2) -> Int {
   pos.1
 }
 
-pub fn directions8() -> Set(Pos2) {
+fn directions9() -> Set(Pos2) {
   set.from_list({
-    use x <- list.flat_map(over: [-1, 0, 1])
-    use y <- list.flat_map(over: [-1, 0, 1])
-    let pos = #(x, y)
-    use <- bool.guard(when: pos == zero, return: [])
-    [pos]
+    use x <- list.flat_map([-1, 0, 1])
+    use y <- list.map([-1, 0, 1])
+    #(x, y)
   })
 }
 
+pub fn directions8() -> Set(Pos2) {
+  set.delete(from: directions9(), this: zero)
+}
+
 pub fn add(p1: Pos2, p2: Pos2) -> Pos2 {
   #(p1.0 + p2.0, p1.1 + p2.1)
 }
@@ -39,10 +41,7 @@ pub fn mul(p: Pos2, by scalar: Int) -> Pos2 {
 }
 
 pub fn neighbours8(p: Pos2) -> Set(Pos2) {
-  directions8()
-  |> set.to_list
-  |> list.map(with: add(p, _))
-  |> set.from_list
+  setx.map(directions8(), with: add(p, _))
 }
 
 pub fn manhattan_dist(from p1: Pos2, to p2: Pos2) -> Int {
diff --git a/aoc-2020-gleam/src/util/pos3.gleam b/aoc-2020-gleam/src/util/pos3.gleam
index 3787c19..e493187 100644
--- a/aoc-2020-gleam/src/util/pos3.gleam
+++ b/aoc-2020-gleam/src/util/pos3.gleam
@@ -1,30 +1,29 @@
 import gleam/list
-import gleam/bool
 import gleam/set.{type Set}
+import ext/setx
 
 pub type Pos3 =
   #(Int, Int, Int)
 
 pub const zero = #(0, 0, 0)
 
-fn directions26() -> Set(Pos3) {
+fn directions27() -> Set(Pos3) {
   set.from_list({
-    use x <- list.flat_map(over: [-1, 0, 1])
-    use y <- list.flat_map(over: [-1, 0, 1])
-    use z <- list.flat_map(over: [-1, 0, 1])
-    let pos = #(x, y, z)
-    use <- bool.guard(when: pos == zero, return: [])
-    [pos]
+    use x <- list.flat_map([-1, 0, 1])
+    use y <- list.flat_map([-1, 0, 1])
+    use z <- list.map([-1, 0, 1])
+    #(x, y, z)
   })
 }
 
+fn directions26() -> Set(Pos3) {
+  set.delete(from: directions27(), this: zero)
+}
+
 pub fn add(p1: Pos3, p2: Pos3) -> Pos3 {
   #(p1.0 + p2.0, p1.1 + p2.1, p1.2 + p2.2)
 }
 
 pub fn neighbours26(p: Pos3) -> Set(Pos3) {
-  directions26()
-  |> set.to_list
-  |> list.map(with: add(p, _))
-  |> set.from_list
+  setx.map(directions26(), with: add(p, _))
 }
diff --git a/aoc-2020-gleam/src/util/pos4.gleam b/aoc-2020-gleam/src/util/pos4.gleam
index a96bcca..c2ab1c7 100644
--- a/aoc-2020-gleam/src/util/pos4.gleam
+++ b/aoc-2020-gleam/src/util/pos4.gleam
@@ -1,31 +1,30 @@
 import gleam/list
-import gleam/bool
 import gleam/set.{type Set}
+import ext/setx
 
 pub type Pos4 =
   #(Int, Int, Int, Int)
 
 pub const zero = #(0, 0, 0, 0)
 
-fn directions80() -> Set(Pos4) {
+fn directions81() -> Set(Pos4) {
   set.from_list({
-    use x <- list.flat_map(over: [-1, 0, 1])
-    use y <- list.flat_map(over: [-1, 0, 1])
-    use z <- list.flat_map(over: [-1, 0, 1])
-    use w <- list.flat_map(over: [-1, 0, 1])
-    let pos = #(x, y, z, w)
-    use <- bool.guard(when: pos == zero, return: [])
-    [pos]
+    use x <- list.flat_map([-1, 0, 1])
+    use y <- list.flat_map([-1, 0, 1])
+    use z <- list.flat_map([-1, 0, 1])
+    use w <- list.map([-1, 0, 1])
+    #(x, y, z, w)
   })
 }
 
+fn directions80() -> Set(Pos4) {
+  set.delete(from: directions81(), this: zero)
+}
+
 pub fn add(p1: Pos4, p2: Pos4) -> Pos4 {
   #(p1.0 + p2.0, p1.1 + p2.1, p1.2 + p2.2, p1.3 + p2.3)
 }
 
 pub fn neighbours80(p: Pos4) -> Set(Pos4) {
-  directions80()
-  |> set.to_list
-  |> list.map(with: add(p, _))
-  |> set.from_list
+  setx.map(directions80(), with: add(p, _))
 }