Finished day 10 in roc.

roc/day10.roc

@@ -26,6 +26,14 @@ connect = \firstEff, secondEff ->
 
         { state: res2.state, ticks: List.concat res1.ticks res2.ticks }
 
+mapChunks : List a, Nat, (List a -> b) -> List b
+mapChunks = \list, len, fn ->
+    listLen = List.len list
+    List.range {start: At 0, end: Before listLen, step: len}
+        |> List.map \start ->
+            List.sublist list {start, len}
+                |> fn
+
 sequence : List Eff -> Eff
 sequence = \list ->
     List.walk list empty \effects, elem -> connect effects elem
@@ -89,12 +97,25 @@ main =
         [20, 60, 100, 140, 180, 220]
         |> List.mapTry getStrength
         |> Result.map List.sum
+        |> \str -> when str is
+            Ok num ->
+                num
+            Err _ ->
+                crash "Index out of bounds"
+    
+    _ <- totalStrength
+        |> Num.toStr
+        |> Stdout.line
+        |> Task.await
 
-    when totalStrength is
-        Ok num ->
-            num
-            |> Num.toStr
-            |> Stdout.line
-
-        Err _ ->
-            crash "Index out of bounds"
+    image = cycles
+        |> mapChunks 40 \line ->
+            List.mapWithIndex line \x, column ->
+                    if Num.abs (x - (Num.intCast column)) < 2 then
+                        "#"
+                    else
+                        "."
+            |> Str.joinWith ""
+        |> Str.joinWith "\n"
+    
+    Stdout.line image