Minor refactors

haskell/Pre.hs

@@ -11,6 +11,7 @@ module Pre (
     module Data.Char,
     module Data.Foldable,
     module Data.Foldable1,
+    module Data.Function,
     module Data.Functor,
     module Data.List,
     module Data.List.Extra,
@@ -57,6 +58,7 @@ import Data.Bool
 import Data.Char
 import Data.Foldable hiding (foldl1, foldr1, maximum, maximumBy, minimum, minimumBy)
 import Data.Foldable1
+import Data.Function
 import Data.Functor
 import Data.List (sortOn, tails, transpose)
 import Data.List.Extra (dropEnd, enumerate)

haskell/Puzzles/Day8.hs

@@ -2,6 +2,7 @@ module Puzzles.Day8 (puzzle) where
 
 import Pre
 
+import Control.Lens
 import Data.DisjointSet qualified as DS
 import Data.Text.Lazy qualified as TL
 import Linear.Metric
@@ -27,7 +28,8 @@ puzzle =
                     . connectBoxes
             , uncurry . const $
                 TL.show
-                    . maybe (error "sets never unified") (\((V3 x1 _ _, V3 x2 _ _), _) -> x1 * x2)
+                    . uncurry ((*) `on` view _x)
+                    . maybe (error "sets never unified") fst
                     . lastMay
                     . takeWhile ((> 1) . DS.sets . snd)
                     . connectBoxes

haskell/aoc.cabal

@@ -48,6 +48,7 @@ executable aoc
         exceptions,
         extra,
         filepath,
+        lens,
         linear,
         massiv,
         megaparsec,