Add remaining haskell book exercises

Haskell-book/19/shawty/.gitignore

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+.stack-work/
+shawty.cabal
+*~

Haskell-book/19/shawty/ChangeLog.md

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+# Changelog for shawty
+
+## Unreleased changes

Haskell-book/19/shawty/LICENSE

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+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/19/shawty/README.md

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+# shawty

Haskell-book/19/shawty/Setup.hs

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+import Distribution.Simple
+main = defaultMain

Haskell-book/19/shawty/app/Main.hs

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+{-# LANGUAGE OverloadedStrings #-}
+
+module Main where
+
+import Control.Monad (replicateM)
+import Control.Monad.IO.Class (liftIO)
+import qualified Data.ByteString.Char8 as BC
+import Data.Text.Encoding (decodeUtf8, encodeUtf8)
+import qualified Data.Text.Lazy as TL
+import qualified Database.Redis as R
+import Network.URI (URI, parseURI)
+import qualified System.Random as SR
+import Web.Scotty
+
+alphaNum :: String
+alphaNum = ['A'..'Z'] ++ ['0'..'9']
+
+randomElement :: String -> IO Char
+randomElement xs = do
+    let maxIndex :: Int
+        maxIndex = length xs - 1
+    -- Right of arrow is IO Int,
+    -- so randomDigit is Int
+    randomDigit <- SR.randomRIO (0, maxIndex)
+    return (xs !! randomDigit)
+
+shortyGen :: IO [Char]
+shortyGen =
+    replicateM 7 (randomElement alphaNum)
+
+saveURI :: R.Connection
+        -> BC.ByteString
+        -> BC.ByteString
+        -> IO (Either R.Reply R.Status)
+saveURI conn shortURI uri = R.runRedis conn $ R.set shortURI uri
+
+getURI :: R.Connection
+       -> BC.ByteString
+       -> IO (Either R.Reply (Maybe BC.ByteString))
+getURI conn shortURI = R.runRedis conn $ R.get shortURI
+
+linkShorty :: String -> String
+linkShorty shorty =
+    concat
+    [ "<a href=\""
+    , shorty
+    , "\">Copy and paste your short URL</a>"
+    ]
+
+-- TL.concat :: [TL.Text] -> TL.Text
+shortyCreated :: Show a
+              => a
+              -> String
+              -> TL.Text
+shortyCreated resp shawty =
+    TL.concat [ TL.pack (show resp)
+              , " shorty is: "
+              , TL.pack (linkShorty shawty)
+              ]
+
+shortyAintUri :: TL.Text -> TL.Text
+shortyAintUri uri =
+    TL.concat
+    [ uri
+    , " wasn't a url,"
+    , " did you forget http://?"
+    ]
+
+shortyFound :: TL.Text -> TL.Text
+shortyFound tbs =
+    TL.concat
+    [ "<a href=\""
+    , tbs, "\">"
+    , tbs, "</a>"
+    ]
+
+app :: R.Connection
+    -> ScottyM ()
+app rConn = do
+    get "/" $ do
+        uri <- param "uri"
+        let parsedUri :: Maybe URI
+            parsedUri = parseURI (TL.unpack uri)
+        case parsedUri of
+          Just _ -> do
+              shawty <- liftIO shortyGen
+              let shorty = BC.pack shawty
+                  uri' = encodeUtf8 (TL.toStrict uri)
+              resp <- liftIO (saveURI rConn shorty uri')
+              html (shortyCreated resp shawty)
+          Nothing -> text (shortyAintUri uri)
+    get "/:short" $ do
+        short <- param "short"
+        uri <- liftIO (getURI rConn short)
+        case uri of
+          Left reply -> text (TL.pack (show reply))
+          Right mbBS -> case mbBS of
+                          Nothing -> text "uri not found"
+                          Just bs -> html (shortyFound tbs)
+                              where tbs :: TL.Text
+                                    tbs = TL.fromStrict (decodeUtf8 bs)
+
+
+main :: IO ()
+main = do
+    rConn <- R.connect R.defaultConnectInfo
+    scotty 3000 (app rConn)

Haskell-book/19/shawty/package.yaml

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+name:                shawty
+version:             0.1.0.0
+homepage:            http://github.com
+license:             BSD3
+author:              Chris Allen
+maintainer:          cma@bitemyapp.com
+copyright:           2015, Chris Allen
+build-type:          Simple
+
+synopsis:            URI shortener
+category:            Web
+description:         Please see README.md
+
+dependencies:
+- base >= 4.7 && < 5
+- bytestring
+- hedis
+- mtl
+- network-uri
+- random
+- scotty
+- semigroups
+- text
+- transformers
+
+executables:
+  shawty:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded

Haskell-book/19/shawty/stack.yaml

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+# 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-10.4
+
+# 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/19/shawty/test/Spec.hs

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+main :: IO ()
+main = putStrLn "Test suite not yet implemented"