evoke-0.2021.8.25: src/lib/Evoke/Type/Flag.hs

module Evoke.Type.Flag
  ( Flag(..)
  , options
  ) where

import qualified System.Console.GetOpt as Console

data Flag
  = Help
  | Verbose
  | Version
  deriving (Eq, Show)

options :: [Console.OptDescr Flag]
options =
  [ Console.Option
    ['h', '?']
    ["help"]
    (Console.NoArg Help)
    "shows this help message and exits"
  , Console.Option
    ['v']
    ["version"]
    (Console.NoArg Version)
    "shows the version number and exits"
  , Console.Option
    []
    ["verbose"]
    (Console.NoArg Verbose)
    "outputs derived instances"
  ]