Add remaining haskell book exercises

Haskell-book/23/FizzBuzz.hs

@@ -0,0 +1,29 @@
+module FizzBuzz where
+
+import Control.Monad
+import Control.Monad.Trans.State
+
+fizzBuzz :: Integer -> String
+fizzBuzz n
+  | n `mod` 15 == 0 = "FizzBuzz"
+  | n `mod` 5 == 0 = "Buzz"
+  | n `mod` 3 == 0 = "Fizz"
+  | otherwise = show n
+
+fizzbuzzList :: [Integer] -> [String]
+fizzbuzzList list = execState (mapM_ addResult list) []
+
+addResult :: Integer -> State [String] ()
+addResult n = do
+    xs <- get
+    let result = fizzBuzz n
+    put (result : xs)
+
+fizzbuzzFromTo :: Integer -> Integer -> [String]
+fizzbuzzFromTo from to = execState (mapM_ addResult (genList from [])) []
+    where genList from soFar
+            | from > to = soFar
+            | otherwise = genList (from + 1) (from : soFar)
+
+main :: IO ()
+main = mapM_ putStrLn $ fizzbuzzFromTo 1 100

Haskell-book/23/Moi.hs

@@ -0,0 +1,34 @@
+module Moi where
+
+newtype Moi s a = Moi { runMoi :: s -> (a, s) }
+
+instance Functor (Moi s) where
+    -- fmap :: (a -> b) -> Moi s a -> Moi s b
+    fmap f (Moi g) = Moi (\x -> h $ g x)
+        where h (a, b) = (f a, b)
+
+instance Applicative (Moi s) where
+    -- pure :: a -> Moi s a
+    pure a = Moi (\s -> (a, s))
+    -- (<*>) :: Moi s (a -> b) -> Moi s a -> Moi s b
+    (Moi f) <*> (Moi g) = Moi (\s -> ((fst (f s)) (fst (g s)), s))
+
+instance Monad (Moi s) where
+    return = pure
+    -- (>>=) :: Moi s a -> (a -> Moi s b) -> Moi s b
+    (Moi f) >>= g = Moi (\s -> (runMoi (g (fst (f s)))) (snd (f s)))
+
+get :: Moi s s
+get = Moi $ \a -> (a, a)
+
+put :: s -> Moi s ()
+put s = Moi $ \_ -> ((), s)
+
+exec :: Moi s a -> s -> s
+exec (Moi sa) s = snd (sa s)
+
+eval :: Moi s a -> s -> a
+eval (Moi sa) s = fst (sa s)
+
+modify :: (s -> s) -> Moi s ()
+modify f = Moi $ \a -> ((), f a)

Haskell-book/23/RandomExample/.gitignore

@@ -0,0 +1,3 @@
+.stack-work/
+RandomExample.cabal
+*~

Haskell-book/23/RandomExample/LICENSE

@@ -0,0 +1,30 @@
+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
+      disclaimer in the documentation and/or other materials provided
+      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
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Haskell-book/23/RandomExample/Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

Haskell-book/23/RandomExample/app/Main.hs

@@ -0,0 +1,4 @@
+module Main where
+
+main :: IO ()
+main = return ()

Haskell-book/23/RandomExample/package.yaml

@@ -0,0 +1,34 @@
+name:                RandomExample
+version:             0.1.0.0
+maintainer:          "belka@caraus.de"
+copyright:           "2018 Eugene Wissner"
+
+dependencies:
+- base >= 4.7 && < 5
+- random
+- transformers
+
+library:
+  source-dirs: src
+
+executables:
+  RandomExample-exe:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - RandomExample
+
+tests:
+  RandomExample-test:
+    main:                Spec.hs
+    source-dirs:         test
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - RandomExample

Haskell-book/23/RandomExample/src/RandomExample.hs

@@ -0,0 +1,31 @@
+module RandomExample where
+
+import System.Random
+
+data Die = DieOne
+         | DieTwo
+         | DieThree
+         | DieFour
+         | DieFive
+         | DieSix
+         deriving (Eq, Show)
+
+intToDie :: Int -> Die
+intToDie n =
+    case n of
+      1 -> DieOne
+      2 -> DieTwo
+      3 -> DieThree
+      4 -> DieFour
+      5 -> DieFive
+      6 -> DieSix
+      -- Use 'error' __extermely_ sparingly
+      x -> error $ "intToDie got non 1-6 integer: " ++ show x
+
+rollDieThreeTimes :: (Die, Die, Die)
+rollDieThreeTimes = do
+    let s = mkStdGen 0
+        (d1, s1) = randomR (1, 6) s
+        (d2, s2) = randomR (1, 6) s1
+        (d3, _) = randomR (1, 6) s2
+    (intToDie d1, intToDie d2, intToDie d3)

Haskell-book/23/RandomExample/src/RandomExample2.hs

@@ -0,0 +1,54 @@
+module RandomExample2 where
+
+import Control.Applicative (liftA3)
+import Control.Monad (replicateM)
+import Control.Monad.Trans.State
+import System.Random
+import RandomExample
+
+rollDie :: State StdGen Die
+rollDie = state $ do
+    (n, s) <- randomR (1, 6)
+    return (intToDie n, s)
+
+rollDie' :: State StdGen Die
+rollDie' = intToDie <$> state (randomR (1, 6))
+
+rollDieThreeTimes' :: State StdGen (Die, Die, Die)
+rollDieThreeTimes' = liftA3 (,,) rollDie rollDie rollDie
+
+infiniteDie :: State StdGen [Die]
+infiniteDie = repeat <$> rollDie
+
+nDie :: Int -> State StdGen [Die]
+nDie n = replicateM n rollDie
+
+rollsToGetTwenty :: StdGen -> Int
+rollsToGetTwenty g = go 0 0 g
+    where
+        go :: Int -> Int -> StdGen -> Int
+        go sum count gen
+          | sum >= 20 = count
+          | otherwise =
+              let (die, nextGen) = randomR (1, 6) gen
+               in go (sum + die) (count + 1) nextGen
+
+rollsToGetN :: Int -> StdGen -> Int
+rollsToGetN limit g = go 0 0 g
+    where
+        go :: Int -> Int -> StdGen -> Int
+        go sum count gen
+          | sum >= limit = count
+          | otherwise =
+              let (die, nextGen) = randomR (1, 6) gen
+               in go (sum + die) (count + 1) nextGen
+
+rollsCountLogged :: Int -> StdGen -> (Int, [Die])
+rollsCountLogged limit g = go 0 0 g []
+    where
+        go :: Int -> Int -> StdGen -> [Die] -> (Int, [Die])
+        go sum count gen dies
+          | sum >= limit = (count, dies)
+          | otherwise =
+              let (die, nextGen) = randomR (1, 6) gen
+               in go (sum + die) (count + 1) nextGen ((intToDie die) : dies)

Haskell-book/23/RandomExample/stack.yaml

@@ -0,0 +1,66 @@
+# 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
+# resolver: ghcjs-0.1.0_ghc-7.10.2
+# resolver:
+#  name: custom-snapshot
+#  location: "./custom-snapshot.yaml"
+resolver: lts-10.9
+
+# 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
+#   extra-dep: true
+#  subdirs:
+#  - auto-update
+#  - wai
+#
+# A package marked 'extra-dep: true' will only be built if demanded by a
+# non-dependency (i.e. a user package), and its test suites and benchmarks
+# will not be run. This is useful for tweaking upstream packages.
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver
+# (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: ">=1.6"
+#
+# 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

Haskell-book/23/RandomExample/test/Spec.hs

@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"