Move and rephrase comment

haskell/Puzzles/Day4.hs

@@ -27,13 +27,13 @@ puzzle =
                 drawGrid (mkGrid input <&> \case InEmpty -> OutEmpty; InRoll -> OutRoll) `shouldBe` t
             describe "frames" do
                 let frames = Seq.fromList $ takeUntil noneAccessible frameStream
-                -- note that `nFrames = Seq.length frames - 1`, but we don't define it as such
-                -- since that would force the expensive evaluation during test tree construction, messing up reporting
                 let nFrames = if isRealData then 58 else 9
                 for_ [0 .. nFrames] \n ->
                     it (show n) . pureGoldenTextFile (path <> "frames/" <> show n) $
                         maybe "frame list too short!" drawGrid (Seq.lookup n frames)
                 it "end" do
+                    -- we can't actually define `nFrames` this way as it would messing up reporting,
+                    -- due to forcing the expensive evaluation during test tree construction
                     Seq.length frames `shouldBe` (nFrames + 1)
                     Just g <- pure $ Seq.lookup nFrames frames
                     (g `shouldSatisfyNamed` "accessible tile found") noneAccessible