Week 10 Ex 1-2

cis194/week10/tien/.gitignore

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

cis194/week10/tien/ChangeLog.md

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+# Changelog for tien
+
+## Unreleased changes

cis194/week10/tien/LICENSE

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+Copyright Author name here (c) 2019
+
+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.

cis194/week10/tien/README.md

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+# tien

cis194/week10/tien/Setup.hs

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+import Distribution.Simple
+main = defaultMain

cis194/week10/tien/app/Main.hs

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+module Main where
+
+main :: IO ()
+main = putStr "No Use"

cis194/week10/tien/package.yaml

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+name:                tien
+version:             0.1.0.0
+github:              "githubuser/tien"
+license:             BSD3
+author:              "Tien"
+maintainer:          "tienlindev@gmail.com"
+copyright:           "2019 Tien"
+
+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/tien#readme>
+
+dependencies:
+- base >= 4.7 && < 5
+- hspec
+
+library:
+  source-dirs: src
+
+executables:
+  tien-exe:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - tien
+
+tests:
+  tien-test:
+    main:                AParserSpec.hs
+    source-dirs:         test
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - tien

cis194/week10/tien/src/AParser.hs

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+{-# OPTIONS_GHC -Wall #-}
+
+{- CIS 194 HW 10
+-}
+module AParser where
+
+import Control.Applicative
+
+import Data.Char
+
+-- A parser for a value of type a is a function which takes a String
+-- represnting the input to be parsed, and succeeds or fails; if it
+-- succeeds, it returns the parsed value along with the remainder of
+-- the input.
+newtype Parser a =
+  Parser
+    { runParser :: String -> Maybe (a, String)
+    }
+
+-- For example, 'satisfy' takes a predicate on Char, and constructs a
+-- parser which succeeds only if it sees a Char that satisfies the
+-- predicate (which it then returns).  If it encounters a Char that
+-- does not satisfy the predicate (or an empty input), it fails.
+satisfy :: (Char -> Bool) -> Parser Char
+satisfy p = Parser f
+  where
+    f [] = Nothing -- fail on the empty input
+    f (x:xs) -- check if x satisfies the predicate
+                        -- if so, return x along with the remainder
+                        -- of the input (that is, xs)
+      | p x = Just (x, xs)
+      | otherwise = Nothing -- otherwise, fail
+
+-- Using satisfy, we can define the parser 'char c' which expects to
+-- see exactly the character c, and fails otherwise.
+char :: Char -> Parser Char
+char c = satisfy (== c)
+
+{- For example:
+
+*Parser> runParser (satisfy isUpper) "ABC"
+Just ('A',"BC")
+*Parser> runParser (satisfy isUpper) "abc"
+Nothing
+*Parser> runParser (char 'x') "xyz"
+Just ('x',"yz")
+
+-}
+-- For convenience, we've also provided a parser for positive
+-- integers.
+posInt :: Parser Integer
+posInt = Parser f
+  where
+    f xs
+      | null ns = Nothing
+      | otherwise = Just (read ns, rest)
+      where
+        (ns, rest) = span isDigit xs
+
+------------------------------------------------------------
+-- Your code goes below here
+------------------------------------------------------------
+-- exercise 1 --
+first :: (a -> b) -> (a, c) -> (b, c)
+first f (x, y) = (f x, y)
+
+instance Functor Parser where
+  fmap f (Parser a) = Parser $ fmap (first f) . a
+
+-- exercise 2 --
+instance Applicative Parser where
+  pure a = Parser (\x -> Just (a, x))
+  Parser f <*> (Parser a) = Parser b
+    where
+      b xs = pure first <*> fmap fst (f xs) <*> (a xs)

cis194/week10/tien/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
+#
+# 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-14.7
+
+# 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
+#   subdirs:
+#   - auto-update
+#   - wai
+packages:
+- .
+# Dependency packages to be pulled from upstream that are not in the resolver.
+# These entries can reference officially published versions as well as
+# forks / in-progress versions pinned to a git hash. For example:
+#
+# extra-deps:
+# - acme-missiles-0.3
+# - git: https://github.com/commercialhaskell/stack.git
+#   commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
+#
+# 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: ">=2.1"
+#
+# 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

cis194/week10/tien/stack.yaml.lock

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+# This file was autogenerated by Stack.
+# You should not edit this file by hand.
+# For more information, please see the documentation at:
+#   https://docs.haskellstack.org/en/stable/lock_files
+
+packages: []
+snapshots:
+- completed:
+    size: 523700
+    url: https://raw.githubusercontent.com/commercialhaskell/stackage-snapshots/master/lts/14/7.yaml
+    sha256: 8e3f3c894be74d71fa4bf085e0a8baae7e4d7622d07ea31a52736b80f8b9bb1a
+  original: lts-14.7

cis194/week10/tien/test/AParserSpec.hs

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+import AParser
+import Data.Char
+import Test.Hspec
+
+main :: IO ()
+main =
+  hspec $ do
+    describe "AParser" $ do
+      let f = toInteger . digitToInt
+      let newParserInt = fmap f (char '2')
+      let testStr1 = "xyz234"
+      let testStr2 = "2xyz"
+      describe "exercise 1" $ do
+        it "should fmap Parser Char to Parser Integer" $ do
+          runParser newParserInt testStr1 `shouldBe` (runParser posInt testStr1)
+          runParser newParserInt testStr2 `shouldBe` (runParser posInt testStr2)