Prefer snake-shift instead of a row-by-row shift

Per the assignment's instructions, the `Shift n` operation should treat
the *entire keyboard* like a cycle and shift that. I was erroneously
treating *each row* like a cycle and shifting those one-by-one.

This change fixes that. In addition, it also:
- Updates README.md with expected inputs and outputs
- Updates test suite
- Adds `split` dependency to {default,shell}.nix

5 files changed, 57 insertions, 37 deletions

diff --git a/scratch/brilliant/App.hs b/scratch/brilliant/App.hs
index bf39de4997ad..0272988f371c 100644
--- a/scratch/brilliant/App.hs
+++ b/scratch/brilliant/App.hs
@@ -7,14 +7,31 @@ import Utils ((|>))
 
 import qualified Data.Char as Char
 import qualified Utils
+import qualified Data.List.Split as Split
 import qualified Keyboard
 import qualified Data.HashMap.Strict as HM
 --------------------------------------------------------------------------------
 
 transform :: Keyboard -> Transform -> Keyboard
-transform (Keyboard xs) HorizontalFlip = xs |> fmap reverse |> Keyboard
-transform (Keyboard xs) VerticalFlip   = xs |> reverse |> Keyboard
-transform (Keyboard xs) (Shift n)      = xs |> fmap (Utils.rotate n) |> Keyboard
+
+transform (Keyboard xs) xform =
+  case xform of
+    HorizontalFlip ->
+      xs
+      |> fmap reverse
+      |> Keyboard
+
+    VerticalFlip ->
+      xs
+      |> reverse
+      |> Keyboard
+
+    Shift n ->
+      xs
+      |> concat
+      |> Utils.rotate n
+      |> Split.chunksOf 10
+      |> Keyboard
 
 retypePassage :: String -> Keyboard -> Maybe String
 retypePassage passage newKeyboard =
diff --git a/scratch/brilliant/README.md b/scratch/brilliant/README.md
index a9019a0f4fc4..60d7de4e25ae 100644
--- a/scratch/brilliant/README.md
+++ b/scratch/brilliant/README.md
@@ -57,11 +57,11 @@ Now a working example:
 $ ./result/transform-keyboard --transforms=HHVS12VHVHS3 --passage='Hello,Brilliant.'
 Typing: "Hello,Brilliant."
 On this keyboard:
-[N][M][,][.][/][Z][X][C][V][B]
-[H][J][K][L][;][A][S][D][F][G]
-[Y][U][I][O][P][Q][W][E][R][T]
-[6][7][8][9][0][1][2][3][4][5]
-Result: QKRRF30LDRRDY1;4
+[H][J][K][L][;][Q][W][E][R][T]
+[Y][U][I][O][P][1][2][3][4][5]
+[6][7][8][9][0][Z][X][C][V][B]
+[N][M][,][.][/][A][S][D][F][G]
+Result: ZIVV4D/O3VV36APF
 ```
 
 ...and an example with an erroneous input (i.e. `!`):
@@ -70,10 +70,10 @@ Result: QKRRF30LDRRDY1;4
 $ ./result/transform-keyboard --transforms=HHVS12VHVHS3 --passage='Hello,Brilliant!'
 Typing: "Hello,Brilliant!"
 On this keyboard:
-[N][M][,][.][/][Z][X][C][V][B]
-[H][J][K][L][;][A][S][D][F][G]
-[Y][U][I][O][P][Q][W][E][R][T]
-[6][7][8][9][0][1][2][3][4][5]
+[H][J][K][L][;][Q][W][E][R][T]
+[Y][U][I][O][P][1][2][3][4][5]
+[6][7][8][9][0][Z][X][C][V][B]
+[N][M][,][.][/][A][S][D][F][G]
 Looks like at least one of the characters in your input passage doesn't fit on our QWERTY keyboard:
 [1][2][3][4][5][6][7][8][9][0]
 [Q][W][E][R][T][Y][U][I][O][P]
diff --git a/scratch/brilliant/Spec.hs b/scratch/brilliant/Spec.hs
index 78ae8cb50cba..e99e025641fa 100644
--- a/scratch/brilliant/Spec.hs
+++ b/scratch/brilliant/Spec.hs
@@ -5,11 +5,12 @@ import Test.Hspec
 import Test.QuickCheck
 import Keyboard (Keyboard(..))
 import Transforms (Transform(..))
+import Data.Coerce
+import Utils
 
 import qualified App
 import qualified Keyboard
 import qualified Transforms
-import qualified Utils
 --------------------------------------------------------------------------------
 
 main :: IO ()
@@ -55,12 +56,12 @@ main = hspec $ do
 
     it "shifts any keyboard" $ do
       property $ \first second third fourth n ->
-        App.transform (Keyboard [first, second, third, fourth]) (Shift n) == do
-          Keyboard $ [ Utils.rotate n first
-                     , Utils.rotate n second
-                     , Utils.rotate n third
-                     , Utils.rotate n fourth
-                     ]
+        App.transform (Keyboard [first, second, third, fourth]) (Shift n)
+        |> (coerce :: Keyboard -> [[Char]])
+        |> concat ==
+          [first, second, third, fourth]
+            |> concat
+            |> Utils.rotate n
 
     it "flips a QWERTY keyboard horizontally" $ do
       App.transform Keyboard.qwerty HorizontalFlip == do
@@ -72,27 +73,27 @@ main = hspec $ do
 
     it "flips a keyboard vertically" $ do
       App.transform Keyboard.qwerty VerticalFlip == do
-        Keyboard $ [ ['Z','X','C','V','B','N','M',',','.','/']
-                   , ['A','S','D','F','G','H','J','K','L',';']
-                   , ['Q','W','E','R','T','Y','U','I','O','P']
-                   , ['1','2','3','4','5','6','7','8','9','0']
-                   ]
+        Keyboard [ ['Z','X','C','V','B','N','M',',','.','/']
+                 , ['A','S','D','F','G','H','J','K','L',';']
+                 , ['Q','W','E','R','T','Y','U','I','O','P']
+                 , ['1','2','3','4','5','6','7','8','9','0']
+                 ]
 
     it "shifts a keyboard left N times" $ do
       App.transform Keyboard.qwerty (Shift 2) == do
-        Keyboard $ [ ['3','4','5','6','7','8','9','0','1','2']
-                   , ['E','R','T','Y','U','I','O','P','Q','W']
-                   , ['D','F','G','H','J','K','L',';','A','S']
-                   , ['C','V','B','N','M',',','.','/','Z','X']
-                   ]
+        Keyboard [ ['3','4','5','6','7','8','9','0','Q','W']
+                 , ['E','R','T','Y','U','I','O','P','A','S']
+                 , ['D','F','G','H','J','K','L',';','Z','X']
+                 , ['C','V','B','N','M',',','.','/','1','2']
+                 ]
 
     it "shifts right negative amounts" $ do
       App.transform Keyboard.qwerty (Shift (-3)) == do
-        Keyboard $ [ ['8','9','0','1','2','3','4','5','6','7']
-                   , ['I','O','P','Q','W','E','R','T','Y','U']
-                   , ['K','L',';','A','S','D','F','G','H','J']
-                   , [',','.','/','Z','X','C','V','B','N','M']
-                   ]
+        Keyboard [ [',','.','/','1','2','3','4','5','6','7']
+                 , ['8','9','0','Q','W','E','R','T','Y','U']
+                 , ['I','O','P','A','S','D','F','G','H','J']
+                 , ['K','L',';','Z','X','C','V','B','N','M']
+                 ]
 
   describe "Transforms.optimize" $ do
     it "removes superfluous horizontal transformations" $ do
diff --git a/scratch/brilliant/default.nix b/scratch/brilliant/default.nix
index 83c62a3d2eba..5a0ece741764 100644
--- a/scratch/brilliant/default.nix
+++ b/scratch/brilliant/default.nix
@@ -5,9 +5,10 @@ let
     rev = "afa9ca61924f05aacfe495a7ad0fd84709d236cc";
   }) {};
 
-  ghc = pkgs.haskellPackages.ghcWithPackages (hpkgs: [
-    hpkgs.optparse-applicative
-    hpkgs.unordered-containers
+  ghc = pkgs.haskellPackages.ghcWithPackages (hpkgs: with hpkgs; [
+    optparse-applicative
+    unordered-containers
+    split
   ]);
 in pkgs.stdenv.mkDerivation {
   name = "transform-keyboard";
diff --git a/scratch/brilliant/shell.nix b/scratch/brilliant/shell.nix
index 02d69d3be01b..d0a6c7e5e6f5 100644
--- a/scratch/brilliant/shell.nix
+++ b/scratch/brilliant/shell.nix
@@ -10,6 +10,7 @@ in pkgs.mkShell {
       hspec
       optparse-applicative
       unordered-containers
+      split
     ]))
   ];
 }