Add homework 3 - brainfsck interpreter (#55)

* Add brainfsck interpreter

* Remove unused imports in Main

* Add .gitignore

* Fix example commands

21 files changed, 800 insertions, 0 deletions

diff --git a/homework/81333/brainfsck/.gitignore b/homework/81333/brainfsck/.gitignore
new file mode 100644
index 0000000..c8db66d
--- /dev/null
+++ b/homework/81333/brainfsck/.gitignore
@@ -0,0 +1,3 @@
+.stack-work/
+brainfsck.cabal
+*~
\ No newline at end of file
diff --git a/homework/81333/brainfsck/ChangeLog.md b/homework/81333/brainfsck/ChangeLog.md
new file mode 100644
index 0000000..76c7fe5
--- /dev/null
+++ b/homework/81333/brainfsck/ChangeLog.md
@@ -0,0 +1,3 @@
+# Changelog for brainfsck
+
+## Unreleased changes
diff --git a/homework/81333/brainfsck/LICENSE b/homework/81333/brainfsck/LICENSE
new file mode 100644
index 0000000..c29d4ee
--- /dev/null
+++ b/homework/81333/brainfsck/LICENSE
@@ -0,0 +1,232 @@
+Copyright Author name here (c) 2018
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
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+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
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+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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diff --git a/homework/81333/brainfsck/README.md b/homework/81333/brainfsck/README.md
new file mode 100644
index 0000000..f9ef70c
--- /dev/null
+++ b/homework/81333/brainfsck/README.md
@@ -0,0 +1,28 @@
+# Brainfsck interpreter
+
+# How to build
+
+Install [stack](https://docs.haskellstack.org/en/stable/README/) build tool
+
+Run following commands from root of project:
+
+Building:
+
+```
+stack build
+```
+
+Executing:
+
+```
+stack exec brainfsck <file_with_code>
+```
+
+# Examples
+
+Examples are in `examples/` folder.
+
+Best ones are: 
+
+* `stack exec brainfsck examples/sierpinski.bf` - outputs sierpinski triangle
+* `echo 0123456789 | stack exec brainfsck examples/pretty.bf` - pretty prints numbers
diff --git a/homework/81333/brainfsck/Setup.hs b/homework/81333/brainfsck/Setup.hs
new file mode 100644
index 0000000..9a994af
--- /dev/null
+++ b/homework/81333/brainfsck/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/homework/81333/brainfsck/app/Main.hs b/homework/81333/brainfsck/app/Main.hs
new file mode 100644
index 0000000..a45882e
--- /dev/null
+++ b/homework/81333/brainfsck/app/Main.hs
@@ -0,0 +1,22 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Main where
+
+import           System.Environment    (getArgs)
+
+import qualified Data.ByteString.Char8 as B
+
+import           Lib                   (blocks)
+
+import           Text.Brainfsck.Parser (parseText)
+import           Text.Brainfsck.Types
+
+main :: IO ()
+main = do
+  args <- getArgs
+  case args of
+    [] -> putStrLn "Usage: stack exec brainfsck-exe <file_with_code>"
+    _ -> do
+      code <- B.readFile $ args !! 0
+      result <- blocks newBlocks $ parseText code
+      B.putStrLn $ r result
diff --git a/homework/81333/brainfsck/brainfsck.cabal b/homework/81333/brainfsck/brainfsck.cabal
new file mode 100644
index 0000000..45f2ba4
--- /dev/null
+++ b/homework/81333/brainfsck/brainfsck.cabal
@@ -0,0 +1,74 @@
+cabal-version: 1.12
+
+-- This file has been generated from package.yaml by hpack version 0.31.1.
+--
+-- see: https://github.com/sol/hpack
+--
+-- hash: 6e461fb9377fd9d13efd7b8e322e93ae789d4e0f77c88584498db65aa15f75ea
+
+name:           brainfsck
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/githubuser/brainfsck#readme>
+homepage:       https://github.com/githubuser/brainfsck#readme
+bug-reports:    https://github.com/githubuser/brainfsck/issues
+author:         Author name here
+maintainer:     example@example.com
+copyright:      2018 Author name here
+license:        BSD3
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    ChangeLog.md
+
+source-repository head
+  type: git
+  location: https://github.com/githubuser/brainfsck
+
+library
+  exposed-modules:
+      Lib
+      Text.Brainfsck.Parser
+      Text.Brainfsck.Types
+      Text.Brainfsck.Util
+  other-modules:
+      Paths_brainfsck
+  hs-source-dirs:
+      src
+  build-depends:
+      attoparsec
+    , base >=4.7 && <5
+    , bytestring
+    , haskeline
+  default-language: Haskell2010
+
+executable brainfsck
+  main-is: Main.hs
+  other-modules:
+      Paths_brainfsck
+  hs-source-dirs:
+      app
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      attoparsec
+    , base >=4.7 && <5
+    , brainfsck
+    , bytestring
+    , haskeline
+  default-language: Haskell2010
+
+test-suite brainfsck-test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules:
+      Paths_brainfsck
+  hs-source-dirs:
+      test
+  ghc-options: -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      attoparsec
+    , base >=4.7 && <5
+    , brainfsck
+    , bytestring
+    , haskeline
+  default-language: Haskell2010
diff --git a/homework/81333/brainfsck/examples/fact.bf b/homework/81333/brainfsck/examples/fact.bf
new file mode 100644
index 0000000..197f331
--- /dev/null
+++ b/homework/81333/brainfsck/examples/fact.bf
@@ -0,0 +1,42 @@
++++++++++++++++++++++++++++++++++			c1v33 : ASCII code of !
+>++++++++++++++++++++++++++++++
++++++++++++++++++++++++++++++++				c2v61 : ASCII code of =
+>++++++++++						c3v10 : ASCII code of EOL
+>+++++++						c4v7  : quantity of numbers to be calculated
+>							c5v0  : current number (one digit)
+>+							c6v1  : current value of factorial (up to three digits)
+<<							c4    : loop counter
+[							block : loop to print one line and calculate next
+>++++++++++++++++++++++++++++++++++++++++++++++++.	c5    : print current number
+------------------------------------------------	c5    : back from ASCII to number
+<<<<.-.>.<.+						c1    : print !_=_
+
+>>>>>							block : print c6 (preserve it)
+>							c7v0  : service zero
+>++++++++++						c8v10 : divizor
+<<							c6    : back to dividend
+[->+>-[>+>>]>[+[-<+>]>+>>]<<<<<<]			c6v0  : divmod algo borrowed from esolangs; results in 0 n d_n%d n%d n/d
+>[<+>-]							c6    : move dividend back to c6 and clear c7
+>[-]							c8v0  : clear c8
+
+>>							block : c10 can have two digits; divide it by ten again
+>++++++++++						c11v10: divizor
+<							c10   : back to dividend
+[->-[>+>>]>[+[-<+>]>+>>]<<<<<]				c10v0 : another divmod algo borrowed from esolangs; results in 0 d_n%d n%d n/d
+>[-]							c11v0 : clear c11
+>>[++++++++++++++++++++++++++++++++++++++++++++++++.[-]]c13v0 : print nonzero n/d (first digit) and clear c13
+<[++++++++++++++++++++++++++++++++++++++++++++++++.[-]] c12v0 : print nonzero n%d (second digit) and clear c12
+<<<++++++++++++++++++++++++++++++++++++++++++++++++.[-]	c9v0  : print any n%d (last digit) and clear c9
+
+<<<<<<.							c3    : EOL
+>>+							c5    : increment current number
+							block : multiply c6 by c5 (don't preserve c6)
+>[>>+<<-]						c6v0  : move c6 to c8
+>>							c8v0  : repeat c8 times
+[
+<<<[>+>+<<-]						c5v0  : move c5 to c6 and c7
+>>[<<+>>-]						c7v0  : move c7 back to c5
+>-
+]
+<<<<-							c4    : decrement loop counter
+]
diff --git a/homework/81333/brainfsck/examples/hello.bf b/homework/81333/brainfsck/examples/hello.bf
new file mode 100644
index 0000000..273b209
--- /dev/null
+++ b/homework/81333/brainfsck/examples/hello.bf
@@ -0,0 +1,3 @@
+>+++++++++[<++++++++>-]<.>+++++++[<++++>-]<+.+++++++..+++.[-]
+>++++++++[<++++>-] <.>+++++++++++[<++++++++>-]<-.--------.+++
+.------.--------.[-]>++++++++[<++++>- ]<+.[-]++++++++++.
diff --git a/homework/81333/brainfsck/examples/input.bf b/homework/81333/brainfsck/examples/input.bf
new file mode 100644
index 0000000..12597fc
--- /dev/null
+++ b/homework/81333/brainfsck/examples/input.bf
@@ -0,0 +1,13 @@
+> +
+[ - >,>+<
+  ----- -----    ; minus 10
+  [              ; if enters means it is not a \n
+    +++++ +++++  ; restore prev value
+    < 
+  ] >>           ; moving forward
+]
+                 ; numbers are 0 0 49 0 50 0 51
+                 ; for input 123
+<<<<[<<]         ; moving to the beginning
+>>               ; reaching first char
+[.>>]            ; just printing till end
diff --git a/homework/81333/brainfsck/examples/pretty.bf b/homework/81333/brainfsck/examples/pretty.bf
new file mode 100644
index 0000000..069aa4d
--- /dev/null
+++ b/homework/81333/brainfsck/examples/pretty.bf
@@ -0,0 +1,31 @@
+>>>>+>+++>+++>>>>>+++[
+  >,+>++++[>++++<-]>[<<[-[->]]>[<]>-]<<[
+    >+>+>>+>+[<<<<]<+>>[+<]<[>]>+[[>>>]>>+[<<<<]>-]+<+>>>-[
+      <<+[>]>>+<<<+<+<--------[
+        <<-<<+[>]>+<<-<<-[
+          <<<+<-[>>]<-<-<<<-<----[
+            <<<->>>>+<-[
+              <<<+[>]>+<<+<-<-[
+                <<+<-<+[>>]<+<<<<+<-[
+                  <<-[>]>>-<<<-<-<-[
+                    <<<+<-[>>]<+<<<+<+<-[
+                      <<<<+[>]<-<<-[
+                        <<+[>]>>-<<<<-<-[
+                          >>>>>+<-<<<+<-[
+                            >>+<<-[
+                              <<-<-[>]>+<<-<-<-[
+                                <<+<+[>]<+<+<-[
+                                  >>-<-<-[
+                                    <<-[>]<+<++++[<-------->-]++<[
+                                      <<+[>]>>-<-<<<<-[
+                                        <<-<<->>>>-[
+                                          <<<<+[>]>+<<<<-[
+                                            <<+<<-[>>]<+<<<<<-[
+                                              >>>>-<<<-<-
+  ]]]]]]]]]]]]]]]]]]]]]]>[>[[[<<<<]>+>>[>>>>>]<-]<]>>>+>>>>>>>+>]<
+]<[-]<<<<<<<++<+++<+++[
+  [>]>>>>>>++++++++[<<++++>++++++>-]<-<<[-[<+>>.<-]]<<<<[
+    -[-[>+<-]>]>>>>>[.[>]]<<[<+>-]>>>[<<++[<+>--]>>-]
+    <<[->+<[<++>-]]<<<[<+>-]<<<<
+  ]>>+>>>--[<+>---]<.>>[[-]<<]<
+]
diff --git a/homework/81333/brainfsck/examples/sierpinski.bf b/homework/81333/brainfsck/examples/sierpinski.bf
new file mode 100644
index 0000000..4c66685
--- /dev/null
+++ b/homework/81333/brainfsck/examples/sierpinski.bf
@@ -0,0 +1,5 @@
+++++++++[>+>++++<<-]>++>>+<[-[>>+<<-]+>>]>+[
+    -<<<[
+        ->[+[-]+>++>>>-<<]<[<]>>++++++[<<+++++>>-]+<<++.[-]<<
+    ]>.>+[>>]>+
+]
diff --git a/homework/81333/brainfsck/examples/squares.bf b/homework/81333/brainfsck/examples/squares.bf
new file mode 100644
index 0000000..fa0a6f8
--- /dev/null
+++ b/homework/81333/brainfsck/examples/squares.bf
@@ -0,0 +1,5 @@
+++++[>+++++<-]>[<+++++>-]+<+[
+    >[>+>+<<-]++>>[<<+>>-]>>>[-]++>[-]+
+    >>>+[[-]++++++>>>]<<<[[<++++++++<++>>-]+<.<[>----<-]<]
+    <<[>>>>>[>>>[-]+++++++++<[>-<-]+++++++++>[-[<->-]+[<<<]]<[>+<-]>]<<-]<<-
+]
diff --git a/homework/81333/brainfsck/examples/sum.bf b/homework/81333/brainfsck/examples/sum.bf
new file mode 100644
index 0000000..df694ec
--- /dev/null
+++ b/homework/81333/brainfsck/examples/sum.bf
@@ -0,0 +1,100 @@
+[
+  A brainfuck program for doing a single digit addition.
+
+  Ex. input: '13' -> output: '4'
+      input: '99' -> output: '18'
+
+  Author: Florian Baierl
+]
+
+initialize #0 with 48 (ASCII char for '0')
+>++++ ++++
+[
+<++++ ++
+>-
+]
+
+save input to #1 and #2
+,>,
+
+substract value from #0 from #1 and #2
+<<
+[
+>-
+>-
+<<-
+]
+
+move to #1
+>
+
+substract from #1 and add to #2; now the answer is in #2
+[
+ ->+<
+]
+
+since we need to modify the answer afterwards write it to #3 and #6
+as well
+>
+[>+>>>+<<<<-]
+
+
+Is the answer bigger than 9?
+to continue the memory tape should look like this:
+0 1 0 (a) b 0
+with the pointer pointing to a
+
+<+
+>>>+++++ +++++ b is 10
+<              point to a
+
++>+<           necessary in case a and b are zero
+
+loop to determine whether a or b reach 0 first
+[->-[>]<<]
+
+<[-
+   a was bigger or equals b
+   the answer is still stored in #6
+
+   subtract 10 from #6 (the answer)
+   >>>>> ----- -----
+
+   write 48 to #4
+   <++++ ++++
+   [
+   <++++ ++
+   >-
+   ]
+   add 48 to #5 and #6
+   <
+   [->+>+<<]
+
+   print out the results
+   >+.>.
+
+   leave loop (back to #2)
+   <<<<
+ ]
+ <[-
+   a was samller so we can simply print the answer out after adding 48 to it
+   the answer is still stored in #6
+
+   >>
+   ++++ ++++
+   [
+   <++++ ++
+   >-
+   ]
+
+   <
+   [
+    ->>>>+<<<<
+   ]
+
+   print #2
+   >>>>.
+
+   we want to leave the loop so go somewhere with the value '0'
+   >
+]
diff --git a/homework/81333/brainfsck/package.yaml b/homework/81333/brainfsck/package.yaml
new file mode 100644
index 0000000..44043aa
--- /dev/null
+++ b/homework/81333/brainfsck/package.yaml
@@ -0,0 +1,51 @@
+name:                brainfsck
+version:             0.1.0.0
+github:              "githubuser/brainfsck"
+license:             BSD3
+author:              "Author name here"
+maintainer:          "example@example.com"
+copyright:           "2018 Author name here"
+
+extra-source-files:
+- README.md
+- ChangeLog.md
+
+# Metadata used when publishing your package
+# synopsis:            Short description of your package
+# category:            Web
+
+# To avoid duplicated efforts in documentation and dealing with the
+# complications of embedding Haddock markup inside cabal files, it is
+# common to point users to the README.md file.
+description:         Please see the README on GitHub at <https://github.com/githubuser/brainfsck#readme>
+
+dependencies:
+- base >= 4.7 && < 5
+- attoparsec
+- bytestring
+- haskeline
+
+library:
+  source-dirs: src
+
+executables:
+  brainfsck:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - brainfsck
+
+tests:
+  brainfsck-test:
+    main:                Spec.hs
+    source-dirs:         test
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - brainfsck
diff --git a/homework/81333/brainfsck/src/Lib.hs b/homework/81333/brainfsck/src/Lib.hs
new file mode 100644
index 0000000..e4cc95c
--- /dev/null
+++ b/homework/81333/brainfsck/src/Lib.hs
@@ -0,0 +1,30 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Lib
+  ( blocks
+  ) where
+
+import           Data.Attoparsec.ByteString.Char8
+import qualified Data.ByteString.Char8            as B
+
+import           Data.Char
+import           Text.Brainfsck.Types
+import           Text.Brainfsck.Util
+
+blocks :: Blocks -> [BFExpr] -> IO Blocks
+blocks b [] = pure b
+blocks (Blocks h b r) (BFRight:es) = blocks (Blocks (h + 1) b r) es
+blocks (Blocks h b r) (BFLeft:es) = blocks (Blocks (max (h - 1) 0) b r) es
+blocks (Blocks h b r) (BFPlus:es) = blocks (Blocks h (inc b h) r) es
+blocks (Blocks h b r) (BFMinus:es) = blocks (Blocks h (dec b h) r) es
+blocks (Blocks h b r) (BFPut:es) =
+  blocks (Blocks h b (r <> B.singleton (chr $ b !! h))) es
+blocks (Blocks h b r) (BFGet:es) = do
+  v <- getChar
+  blocks (Blocks h (load b h $ ord v) r) es
+blocks current@(Blocks h b r) (BFLoop expr:es) = do
+  if b !! h == 0
+    then blocks current es
+    else do
+      newBlocks <- blocks current expr
+      blocks newBlocks ((BFLoop expr) : es)
diff --git a/homework/81333/brainfsck/src/Text/Brainfsck/Parser.hs b/homework/81333/brainfsck/src/Text/Brainfsck/Parser.hs
new file mode 100644
index 0000000..28c019a
--- /dev/null
+++ b/homework/81333/brainfsck/src/Text/Brainfsck/Parser.hs
@@ -0,0 +1,56 @@
+module Text.Brainfsck.Parser
+  ( parseText
+  ) where
+
+import           Control.Applicative
+
+import           Data.Attoparsec.ByteString.Char8
+import qualified Data.ByteString.Char8            as B
+import           Data.Either                      (fromRight)
+
+import           Text.Brainfsck.Types
+
+goRight :: Parser BFExpr
+goRight = do
+  char '>'
+  pure BFRight
+
+goLeft :: Parser BFExpr
+goLeft = do
+  char '<'
+  pure BFLeft
+
+plus :: Parser BFExpr
+plus = do
+  char '+'
+  pure BFPlus
+
+minus :: Parser BFExpr
+minus = do
+  char '-'
+  pure BFMinus
+
+get :: Parser BFExpr
+get = do
+  char ','
+  pure BFGet
+
+put :: Parser BFExpr
+put = do
+  char '.'
+  pure BFPut
+
+bfsymbol :: Parser BFExpr
+bfsymbol = goRight <|> goLeft <|> plus <|> minus <|> get <|> put <|> loop
+
+loop :: Parser BFExpr
+loop = do
+  char '['
+  m <- many' bfsymbol
+  char ']'
+  pure $ BFLoop m
+
+parseText :: B.ByteString -> [BFExpr]
+parseText s =
+  fromRight [] $
+  parseOnly (many' bfsymbol) $ B.filter ((flip elem) "+-,.<>[]") s
diff --git a/homework/81333/brainfsck/src/Text/Brainfsck/Types.hs b/homework/81333/brainfsck/src/Text/Brainfsck/Types.hs
new file mode 100644
index 0000000..5dd26f6
--- /dev/null
+++ b/homework/81333/brainfsck/src/Text/Brainfsck/Types.hs
@@ -0,0 +1,24 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module Text.Brainfsck.Types where
+
+import qualified Data.ByteString.Char8 as B
+
+data BFExpr
+  = BFRight
+  | BFLeft
+  | BFPlus
+  | BFMinus
+  | BFGet
+  | BFPut
+  | BFLoop [BFExpr]
+  deriving (Show)
+
+data Blocks = Blocks
+  { h :: Int
+  , b :: [Int]
+  , r :: B.ByteString
+  } deriving (Show)
+
+newBlocks :: Blocks
+newBlocks = Blocks {h = 0, b = [0,0 ..], r = ""}
diff --git a/homework/81333/brainfsck/src/Text/Brainfsck/Util.hs b/homework/81333/brainfsck/src/Text/Brainfsck/Util.hs
new file mode 100644
index 0000000..fb2d5ad
--- /dev/null
+++ b/homework/81333/brainfsck/src/Text/Brainfsck/Util.hs
@@ -0,0 +1,10 @@
+module Text.Brainfsck.Util where
+
+inc :: [Int] -> Int -> [Int]
+inc b h = take h b <> [b !! h + 1] <> drop (h + 1) b
+
+dec :: [Int] -> Int -> [Int]
+dec b h = take h b <> [b !! h - 1] <> drop (h + 1) b
+
+load :: [Int] -> Int -> Int -> [Int]
+load b h v = take h b <> [v] <> drop (h + 1) b
diff --git a/homework/81333/brainfsck/stack.yaml b/homework/81333/brainfsck/stack.yaml
new file mode 100644
index 0000000..6ad76a0
--- /dev/null
+++ b/homework/81333/brainfsck/stack.yaml
@@ -0,0 +1,64 @@
+# This file was automatically generated by 'stack init'
+#
+# Some commonly used options have been documented as comments in this file.
+# For advanced use and comprehensive documentation of the format, please see:
+# https://docs.haskellstack.org/en/stable/yaml_configuration/
+
+# Resolver to choose a 'specific' stackage snapshot or a compiler version.
+# A snapshot resolver dictates the compiler version and the set of packages
+# to be used for project dependencies. For example:
+#
+# resolver: lts-3.5
+# resolver: nightly-2015-09-21
+# resolver: ghc-7.10.2
+#
+# The location of a snapshot can be provided as a file or url. Stack assumes
+# a snapshot provided as a file might change, whereas a url resource does not.
+#
+# resolver: ./custom-snapshot.yaml
+# resolver: https://example.com/snapshots/2018-01-01.yaml
+resolver: lts-12.18
+
+# User packages to be built.
+# Various formats can be used as shown in the example below.
+#
+# packages:
+# - some-directory
+# - https://example.com/foo/bar/baz-0.0.2.tar.gz
+# - location:
+#    git: https://github.com/commercialhaskell/stack.git
+#    commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+# - location: https://github.com/commercialhaskell/stack/commit/e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#  subdirs:
+#  - auto-update
+#  - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# using the same syntax as the packages field.
+# (e.g., acme-missiles-0.3)
+# extra-deps: []
+
+# Override default flag values for local packages and extra-deps
+# flags: {}
+
+# Extra package databases containing global packages
+# extra-package-dbs: []
+
+# Control whether we use the GHC we find on the path
+# system-ghc: true
+#
+# Require a specific version of stack, using version ranges
+# require-stack-version: -any # Default
+# require-stack-version: ">=1.9"
+#
+# Override the architecture used by stack, especially useful on Windows
+# arch: i386
+# arch: x86_64
+#
+# Extra directories used by stack for building
+# extra-include-dirs: [/path/to/dir]
+# extra-lib-dirs: [/path/to/dir]
+#
+# Allow a newer minor version of GHC than the snapshot specifies
+# compiler-check: newer-minor
diff --git a/homework/81333/brainfsck/test/Spec.hs b/homework/81333/brainfsck/test/Spec.hs
new file mode 100644
index 0000000..cd4753f
--- /dev/null
+++ b/homework/81333/brainfsck/test/Spec.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"