diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 0000000..d31c4e3
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,5 @@
+# Revision history for sodokuSolver
+
+## 0.1.0.0 -- YYYY-mm-dd
+
+* First version. Released on an unsuspecting world.
diff --git a/LICENSE b/LICENSE
new file mode 100644
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,674 @@
+ GNU GENERAL PUBLIC LICENSE
+ Version 3, 29 June 2007
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+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+ 17. Interpretation of Sections 15 and 16.
+
+ If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+ END OF TERMS AND CONDITIONS
+
+ How to Apply These Terms to Your New Programs
+
+ If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+ To do so, attach the following notices to the program. It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+
+ Copyright (C)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see .
+
+Also add information on how to contact you by electronic and paper mail.
+
+ If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+ Copyright (C)
+ This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+ This is free software, and you are welcome to redistribute it
+ under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License. Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+ You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+.
+
+ The GNU General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library. If this is what you want to do, use the GNU Lesser General
+Public License instead of this License. But first, please read
+.
diff --git a/app/Main.hs b/app/Main.hs
new file mode 100644
index 0000000..4b1a75a
--- /dev/null
+++ b/app/Main.hs
@@ -0,0 +1,208 @@
+module Main(main) where
+import Data.Array
+import Data.IntSet (IntSet)
+import qualified Data.IntSet as IS
+import Control.Monad ((>=>))
+import Control.Applicative ((<|>))
+import Data.Char
+-- import Debug.Trace
+import Data.List (foldl')
+import Data.Maybe(fromMaybe)
+
+data Cell = Fixed Int | Possible IntSet
+ deriving (Show, Eq)
+type Grid = Array (Int,Int) Cell
+
+cellToChar :: Cell -> Char
+cellToChar (Fixed n) = intToDigit n
+cellToChar (Possible _) = '.'
+
+showCell :: Cell -> String
+showCell (Fixed x) = show x ++ " "
+showCell (Possible is) = (++ "]") . foldl' (\acc x -> acc ++ if x `IS.member` is then show x else " ") "[" $ [1..9]
+
+showGrid :: Grid -> String
+showGrid = unlines . fmap (fmap cellToChar) . chunksOf 9 . elems
+
+showGridWithPossibilities :: Grid -> String
+showGridWithPossibilities = unlines . map (unwords . map showCell) . rows
+-- I should write index functions for rows and columns
+-- then I could make an abstract access functions and define
+-- the concrete ones using the index function and the abstract
+-- accessors (same for the update ones)
+-- (like prune pruneStructures)
+row :: Grid -> Int -> [Cell]
+row grid rn = [grid ! (rn,i) | i <- [0..8]]
+
+rows :: Grid -> [[Cell]]
+rows grid = [row grid i | i <- [0..8]]
+
+column :: Grid -> Int -> [Cell]
+column grid rn = [grid ! (i,rn) | i <- [0..8]]
+
+columns :: Grid -> [[Cell]]
+columns grid = [column grid i | i <- [0..8]]
+
+sGrid :: Grid -> Int -> [Cell]
+sGrid grid sGridn = [grid ! (a,b) | (a,b) <- intToSGindex sGridn]
+
+sGrids :: Grid -> [[Cell]]
+sGrids grid = [sGrid grid i | i <- [0..8]]
+
+{-# INLINE intToSGindex #-}
+intToSGindex :: Int -> [(Int,Int)]
+intToSGindex 0 = [(x,y) | x <- [0..2], y <- [0..2] ]
+intToSGindex 1 = [(x,y) | x <- [0..2], y <- [3..5] ]
+intToSGindex 2 = [(x,y) | x <- [0..2], y <- [6..8] ]
+intToSGindex 3 = [(x,y) | x <- [3..5], y <- [0..2] ]
+intToSGindex 4 = [(x,y) | x <- [3..5], y <- [3..5] ]
+intToSGindex 5 = [(x,y) | x <- [3..5], y <- [6..8] ]
+intToSGindex 6 = [(x,y) | x <- [6..8], y <- [0..2] ]
+intToSGindex 7 = [(x,y) | x <- [6..8], y <- [3..5] ]
+intToSGindex 8 = [(x,y) | x <- [6..8], y <- [6..8] ]
+intToSGindex _ = []
+
+pruneCells :: [Cell] -> Maybe [Cell]
+pruneCells cells = traverse pruneCell cells
+ where
+ fixeds = IS.fromList [x | Fixed x <- cells]
+
+ pruneCell (Possible xs) = t $ xs IS.\\ fixeds
+ pruneCell (Fixed x) = Just $ Fixed x
+ t x | IS.size x == 0 = Nothing
+ t x | IS.size x == 1 = Just $ Fixed $ head $ IS.toList x
+ t x | otherwise = Just $ Possible x
+
+checkConstraint :: Grid -> Maybe Grid
+checkConstraint grid = case and [abs (x - y ) > 1 | i <- [0..7], j <- [0..8], Fixed x <- [grid ! (i,j)], Fixed y <- [grid ! (i+1,j)]] && and [abs (x - y) > 1 | i <- [0..8], j <- [0..7], Fixed x <- [grid ! (i,j)], Fixed y <- [grid ! (i,j+1)]] of
+ True -> Just grid
+ False -> Nothing
+
+updateRow :: Grid -> [Cell] -> Int -> Grid
+updateRow grid cells rn = grid // zip [(rn,i) | i <- [0..8]] cells
+
+updateRows :: Grid -> [[Cell]] -> Grid
+updateRows grid cellss = grid // concat (zipWith f [0..8] cellss)
+ where
+ f i = zip [(i,x)| x <- [0..8]]
+
+updateColumn :: Grid -> [Cell] -> Int -> Grid
+updateColumn grid cells cn = grid // zip [(i,cn) | i <- [0..8]] cells
+
+updateColumns :: Grid -> [[Cell]] -> Grid
+updateColumns grid cells = grid // concat (zipWith f [0..8] cells)
+ where
+ f i = zip [(x,i)| x <- [0..8]]
+
+updateSGrid :: Grid -> [Cell] -> Int -> Grid
+updateSGrid grid cells sGn = grid // zip (intToSGindex sGn) cells
+
+updateSGrids :: Grid -> [[Cell]] -> Grid
+updateSGrids grid cells = grid // concat (zipWith f [0..8] cells)
+ where
+ f i = zip (intToSGindex i)
+
+{-# INLINE pruneStructures #-}
+pruneStructures :: (Grid -> [[Cell]]) -> (Grid -> [[Cell]] -> Grid) -> Grid -> Maybe Grid
+pruneStructures access update grid = do
+ let rs = access grid
+ prs <- traverse pruneCells rs
+ return $ update grid prs
+
+pruneRows :: Grid -> Maybe Grid
+pruneRows = pruneStructures rows updateRows
+
+pruneColummns :: Grid -> Maybe Grid
+pruneColummns = pruneStructures columns updateColumns
+
+pruneSGrids :: Grid -> Maybe Grid
+pruneSGrids = pruneStructures sGrids updateSGrids
+
+pruneGrid :: Grid -> Maybe Grid
+pruneGrid = pruneRows >=> pruneColummns >=> pruneSGrids
+
+fixGridMaybe :: (Grid -> Maybe Grid) -> Grid -> Maybe Grid
+fixGridMaybe f grid = do
+ x <- f grid
+ if x == grid
+ then return grid
+ else fixGridMaybe f x
+
+prunesGrid :: Grid -> Maybe Grid
+prunesGrid = fixGridMaybe pruneGrid
+
+isFixed :: Cell -> Bool
+isFixed (Fixed _) = True
+isFixed _ = False
+
+isPossible :: Cell -> Bool
+isPossible (Possible _) = True
+isPossible _ = False
+
+allFixed :: Grid -> Bool
+allFixed grid = all isFixed $ elems grid
+
+headL :: [a] -> [a]
+headL [] = []
+headL (x:_) = [x]
+
+travTuple :: (Maybe a, Maybe b) -> Maybe (a,b)
+travTuple (Nothing, _) = Nothing
+travTuple (_,Nothing) = Nothing
+travTuple (Just x, Just y) = Just (x,y)
+
+makeChoice :: Grid -> (Grid,Grid)
+makeChoice grid = splitGrid
+ where
+ smallestCellInd :: ((Int,Int),[Int])
+ smallestCellInd = convert . indHelper $ (assocs grid)
+ convert (c,Possible is) = (c,IS.toList is)
+ convert (_,Fixed _) = error "convert error"
+ indHelper [] = error "We have no choices but aren't done?"
+ indHelper ((_,Fixed _) : xs) = indHelper xs
+ indHelper (t@(_,Possible _) : xs) = indHelper' t xs
+ indHelper' :: ((Int,Int),Cell) -> [((Int,Int),Cell)] -> ((Int,Int),Cell)
+ indHelper' t [] = t
+ indHelper' p@(_,Possible is) (p'@(_, Possible is') : xs) = if IS.size is <= IS.size is' then indHelper' p xs else indHelper' p' xs
+ indHelper' p ((_,(Fixed _)) : xs) = indHelper' p xs
+ indHelper' (_,Fixed _) _ = error "indHelper' impossible branch"
+ splitGrid :: (Grid,Grid)
+ splitGrid = case smallestCellInd of
+ (c,[x,y]) -> (grid // [(c,Fixed x)], grid // [(c,Fixed y)])
+ (c,x:t@(_:_)) -> (grid // [(c,Fixed x)], grid // [(c,Possible $ IS.fromList t)])
+ _ -> error "We just checked the size"
+
+solveSodoku :: Grid -> Maybe Grid
+solveSodoku grid = do
+ nGrid <- prunesGrid grid
+ nGrid' <- checkConstraint nGrid
+ if allFixed nGrid'
+ then return nGrid
+ else do
+ let (x,y) = makeChoice nGrid
+ solveSodoku x <|> solveSodoku y
+
+readSodoku :: String -> Maybe Grid
+readSodoku str | length str == 81 = fmap (listArray ((0,0),(8,8))) . traverse readCell $ str
+ | otherwise = Nothing
+ where
+ readCell :: Char -> Maybe Cell
+ readCell '.' = Just . Possible . IS.fromList $ [1..9]
+ readCell c | isDigit c && c > '0' = Just . Fixed . digitToInt $ c
+ | otherwise = Nothing
+
+
+chunksOf :: Int -> [a] -> [[a]]
+chunksOf _ [] = []
+chunksOf n xs = let (c,txs) = splitAt n xs in c : chunksOf n txs
+
+{-# NOINLINE sodokuStr #-}
+sodokuStr :: String
+sodokuStr = "....4.....9.....6...4.9.1..............1.3..............3.6.2...2.....4.....7...."
+
+main :: IO ()
+main = do
+ putStrLn $ fromMaybe "Unsolvable" $ do
+ sodoku <- readSodoku sodokuStr
+ solution <- solveSodoku sodoku
+ return $ showGrid solution
diff --git a/default.nix b/default.nix
new file mode 100644
index 0000000..532f063
--- /dev/null
+++ b/default.nix
@@ -0,0 +1,2 @@
+{ pkgs , compiler ? "ghc902"}:
+ pkgs.haskell.packages.${compiler}.callPackage ./sodokuSolver.nix { }
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..b6babf2
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,43 @@
+{
+ "nodes": {
+ "flake-utils": {
+ "locked": {
+ "lastModified": 1667395993,
+ "narHash": "sha256-nuEHfE/LcWyuSWnS8t12N1wc105Qtau+/OdUAjtQ0rA=",
+ "owner": "numtide",
+ "repo": "flake-utils",
+ "rev": "5aed5285a952e0b949eb3ba02c12fa4fcfef535f",
+ "type": "github"
+ },
+ "original": {
+ "owner": "numtide",
+ "repo": "flake-utils",
+ "type": "github"
+ }
+ },
+ "nixpkgs": {
+ "locked": {
+ "lastModified": 1670267727,
+ "narHash": "sha256-hUFAn5gjNHIBpLQT0CmqpuQjQwgWUm+D6aziGAYsDmw=",
+ "owner": "NixOS",
+ "repo": "nixpkgs",
+ "rev": "a5f661b80e4c163510a5013b585a040a5c7ef55e",
+ "type": "github"
+ },
+ "original": {
+ "owner": "NixOS",
+ "ref": "nixpkgs-unstable",
+ "repo": "nixpkgs",
+ "type": "github"
+ }
+ },
+ "root": {
+ "inputs": {
+ "flake-utils": "flake-utils",
+ "nixpkgs": "nixpkgs"
+ }
+ }
+ },
+ "root": "root",
+ "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..3c351e7
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,82 @@
+{
+ description = "choir Mail automatisation";
+
+ inputs = {
+ nixpkgs.url = github:NixOS/nixpkgs/nixpkgs-unstable;
+ flake-utils.url = github:numtide/flake-utils;
+ };
+
+ outputs = {self, nixpkgs, flake-utils} :
+ let
+ # name to be used as identifier for editor environments and such
+ name = "Application";
+ compiler = "ghc902";
+
+ in
+ flake-utils.lib.eachDefaultSystem ( system:
+ let
+ pkgs = import nixpkgs {inherit system;};
+ hpkgs = pkgs.haskell.packages.${compiler};
+ in {
+ packages = { default = (import ./default.nix) {inherit pkgs compiler;};};
+
+
+ devShells =
+ rec {
+ # This sets the default devShell
+ default = kakoune;
+ kakoune =
+ let
+ haskell-language-server = hpkgs.haskell-language-server;
+ myKakoune =
+ let
+ # this could also be done by generating toml with the
+ # nixpkgs lib, but I'm lazy
+ kak-lsp-config = pkgs.writeTextFile {
+ name = "kak-lsp-config.toml";
+ text = ''
+ [language.haskell]
+ filetypes = ["haskell"]
+ roots = ["Setup.hs", "stack.yaml", "*.cabal"]
+ command = "haskell-language-server-wrapper"
+ args = ["--lsp"]
+ '';
+ };
+ config = pkgs.writeTextFile (rec {
+ name = "kakrc.kak";
+ destination = "/share/kak/autoload/${name}";
+ text = ''
+ colorscheme solarized-dark
+ set global tabstop 2
+ set global indentwidth 2
+ eval %sh{kak-lsp --kakoune --session $kak_session -c ${kak-lsp-config}}
+ # eval %sh{kak-lsp --kakoune --session $kak_session -c ${kak-lsp-config} --log /tmp/kak-lpsLog -vvvv}
+ hook global WinSetOption filetype=(haskell|nix) %{
+ lsp-auto-hover-enable
+ lsp-enable-window
+ }
+ add-highlighter global/ number-lines
+ map global normal ': fzf-mode'
+ '';
+ });
+ in
+ pkgs.kakoune.override {
+ plugins = with pkgs.kakounePlugins; [fzf-kak kak-lsp config];
+ };
+ in
+ pkgs.mkShell {
+ inputsFrom = [self.outputs.packages.${system}.default];
+ packages = [myKakoune haskell-language-server pkgs.git pkgs.fzf hpkgs.cabal2nix pkgs.cabal-install pkgs.zlib.dev];
+ # TODO only try to start the kakoune session if no session with that
+ # name exists
+ shellHook = ''
+ alias ..="cd .."
+ export KAKOUNE_CONFIG_DIR="/dev/null/"
+ kak -d -s ${name} &
+ alias vim="kak -c ${name}"
+ '';
+ };
+ };
+ }
+ );
+}
diff --git a/sodokuSolver.cabal b/sodokuSolver.cabal
new file mode 100644
index 0000000..04b1f92
--- /dev/null
+++ b/sodokuSolver.cabal
@@ -0,0 +1,82 @@
+cabal-version: 3.0
+-- The cabal-version field refers to the version of the .cabal specification,
+-- and can be different from the cabal-install (the tool) version and the
+-- Cabal (the library) version you are using. As such, the Cabal (the library)
+-- version used must be equal or greater than the version stated in this field.
+-- Starting from the specification version 2.2, the cabal-version field must be
+-- the first thing in the cabal file.
+
+-- Initial package description 'sodokuSolver' generated by
+-- 'cabal init'. For further documentation, see:
+-- http://haskell.org/cabal/users-guide/
+--
+-- The name of the package.
+name: sodokuSolver
+
+-- The package version.
+-- See the Haskell package versioning policy (PVP) for standards
+-- guiding when and how versions should be incremented.
+-- https://pvp.haskell.org
+-- PVP summary: +-+------- breaking API changes
+-- | | +----- non-breaking API additions
+-- | | | +--- code changes with no API change
+version: 0.1.0.0
+
+-- A short (one-line) description of the package.
+-- synopsis:
+
+-- A longer description of the package.
+-- description:
+
+-- URL for the project homepage or repository.
+homepage: https://git.nerfingen.de/nerf/sodokuSolver
+
+-- The license under which the package is released.
+license: GPL-3.0-or-later
+
+-- The file containing the license text.
+license-file: LICENSE
+
+-- The package author(s).
+author: nerf van nerfingen
+
+-- An email address to which users can send suggestions, bug reports, and patches.
+maintainer: dennis@frieberg.de
+
+-- A copyright notice.
+-- copyright:
+build-type: Simple
+
+-- Extra doc files to be distributed with the package, such as a CHANGELOG or a README.
+extra-doc-files: CHANGELOG.md
+
+-- Extra source files to be distributed with the package, such as examples, or a tutorial module.
+-- extra-source-files:
+
+common warnings
+ ghc-options: -Wall
+
+executable sodokuSolver
+ -- Import common warning flags.
+ import: warnings
+
+ -- .hs or .lhs file containing the Main module.
+ main-is: Main.hs
+
+ -- Modules included in this executable, other than Main.
+ -- other-modules:
+
+ -- LANGUAGE extensions used by modules in this package.
+ -- other-extensions:
+
+ -- Other library packages from which modules are imported.
+ build-depends: base ^>=4.15.1.0
+ , array
+ , containers
+
+ -- Directories containing source files.
+ hs-source-dirs: app
+ optimization: 2
+
+ -- Base language which the package is written in.
+ default-language: Haskell2010
diff --git a/sodokuSolver.nix b/sodokuSolver.nix
new file mode 100644
index 0000000..bcd3246
--- /dev/null
+++ b/sodokuSolver.nix
@@ -0,0 +1,12 @@
+{ mkDerivation, array, base, containers, lib }:
+mkDerivation {
+ pname = "sodokuSolver";
+ version = "0.1.0.0";
+ src = ./.;
+ isLibrary = false;
+ isExecutable = true;
+ executableHaskellDepends = [ array base containers ];
+ homepage = "https://git.nerfingen.de/nerf/sodokuSolver";
+ license = lib.licenses.gpl3Plus;
+ mainProgram = "sodokuSolver";
+}