計算機科学のブログ

name:                lesson
version:             0.1.0.0
github:              "githubuser/lesson"
license:             BSD3
author:              "Author name here"
maintainer:          "example@example.com"
copyright:           "2022 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/lesson#readme>

dependencies:
- base >= 4.7 && < 5
- bytestring
- random

library:
  source-dirs: src

executables:
  lesson-exe:
    main:                Main.hs
    source-dirs:         app
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - lesson

tests:
  lesson-test:
    main:                Spec.hs
    source-dirs:         test
    ghc-options:
    - -threaded
    - -rtsopts
    - -with-rtsopts=-N
    dependencies:
    - lesson

default-extensions: OverloadedStrings

module Main where

import Lib

p :: IO ()
p = do
  c <- randomChar
  print c

iter n =
  if n == 0
    then return ()
    else do
      p
      iter (n - 1)

main :: IO ()
main = iter 50

module Lib
  ( randomChar,
  )
where

import System.Random (randomRIO)

randomChar :: IO Char
randomChar = do
  int <- randomRIO (0, 255)
  return $ toEnum int

% stack exec lesson-exe
'5'
'\181'
'f'
'\162'
'/'
'j'
't'
'\174'
'^'
'\177'
'o'
'\f'
'\251'
's'
'p'
'\252'
'\129'
'a'
'\178'
'v'
'\191'
'\218'
'T'
'\156'
'\190'
'\212'
'@'
'@'
'N'
'^'
'\r'
'\175'
'#'
'\128'
'>'
'\146'
'\226'
'\177'
'A'
'\ETX'
'\247'
'}'
'\130'
'\251'
'5'
'\210'
'\143'
'5'
'\195'
'\194'
%