@hackage / ConsoleAsk

Simple CLI user input library

Latest0.1.0.1

About

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  • Last updated , by t_sasaki915
  • License MIT
  • Categories Systems Programming

  • Maintained by: netst915@gmail.com

  • Lottery factor: 1

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ConsoleAsk

Simple CLI user input library

Example

import Data.Functor ((<&>))

import Data.Text (Text)

import Text.Parsec (char, digit, many1)

import Text.Regex.TDFA ((=~))



import System.Console.Ask (Ask, ask, askOptional, askOrElse, runAsk, defaultBehaviour)

import System.Console.Ask.Askable (Askable (fromText), fromParsec)



data UserInformation = UserInformation

    { name                   :: Text

    , age                    :: Maybe Int

    , birthday               :: Date

    , notificationPreference :: NotificationPreference

    } deriving Show



data NotificationPreference = NotificationPreference

    { needNotifications :: Bool

    , emailAddress      :: Maybe EmailAddress

    } deriving Show



askUserInformation :: Ask UserInformation

askUserInformation =

    UserInformation

        <$> ask         "What is your name?"

        <*> askOptional "How old are you?"

        <*> ask         "When is your birthday?"

        <*> askNotificationPreference



askNotificationPreference :: Ask NotificationPreference

askNotificationPreference = do

    needNotifications' <- askOrElse "Do you need our update notifications?" False



    emailAddress' <-

        if needNotifications'

            then Just <$> ask "What is your email address?"

            else pure Nothing



    pure NotificationPreference

        { needNotifications = needNotifications'

        , emailAddress      = emailAddress'

        }



newtype EmailAddress = EmailAddress Text deriving Show



instance Askable EmailAddress where

    fromText text =

        if text =~ ("[a-zA-Z0-9+._-]+@[a-zA-Z-]+\\.[a-z]+" :: Text)

            then Just (EmailAddress text)

            else Nothing



data Date = Date Int Int deriving Show



instance Askable Date where

    fromText = fromParsec $ do

        day   <- many1 digit <&> read

        _     <- char '/'

        month <- many1 digit <&> read



        pure (Date day month)



main :: IO ()

main = do

    userInfo <- runAsk defaultBehaviour askUserInformation



    print userInfo

What is your name?
> Toma Sasaki

How old are you?
>

When is your birthday?
> 15/9

Do you need our update notifications? (Default: False)
> aye

What is your email address?
> me@t-sasaki.net

UserInformation
    { name = "Toma Sasaki"
    , age = Nothing
    , birthday = Date 15 9
    , notificationPreference =
        NotificationPreference
            { needNotifications = True
            , emailAddress = Just (EmailAddress "me@t-sasaki.net")
            }
    }

Features

  • Automatically parses input values to Askable instances. (See also: Askable.hs)
import Control.Monad.IO.Class (liftIO)

import Data.Text (Text)

import qualified Data.Text as Text

import qualified Data.Text.IO as TextIO



import System.Console.Ask (Ask, ask, askOptional, askOrElse, defaultBehaviour, runAsk)



main :: IO ()

main = runAsk defaultBehaviour $ do

    name              <- ask         "What is your name?"               :: Ask Text

    age               <- askOptional "How old are you?"                 :: Ask (Maybe Int)

    needNotifications <- askOrElse   "Do you need notifications?" False :: Ask Bool



    liftIO $ do

        TextIO.putStrLn ("Name: " <> name)

        TextIO.putStrLn ("Age: " <> Text.show age)

        TextIO.putStrLn ("Need notifications: " <> Text.show needNotifications)

What is your name?
> Toma Sasaki

How old are you?
> a
Invalid input.

How old are you?
> 18

Do you need notifications? (Default: False)
> no

Name: "Toma Sasaki"
Age: 18
Need notifications: False
  • Askable supports both Text -> Maybe a and parsec.
import Data.Functor ((<&>))

import Data.Text (Text)

import Text.Parsec (char, digit, many1)

import Text.Regex.TDFA ((=~))



import System.Console.Ask.Askable (Askable (fromText), fromParsec)



newtype EmailAddress = EmailAddress Text deriving Show



instance Askable EmailAddress where

    fromText text =

        if text =~ ("[a-zA-Z0-9+._-]+@[a-zA-Z-]+\\.[a-z]+" :: Text)

            then Just (EmailAddress text)

            else Nothing



data Date = Date Int Int deriving Show



instance Askable Date where

    fromText = fromParsec $ do

        day   <- many1 digit <&> read

        _     <- char '/'

        month <- many1 digit <&> read



        pure (Date day month)
  • Custom prompt
import Control.Monad.IO.Class (liftIO)

import Data.Text (Text)

import qualified Data.Text as Text

import qualified Data.Text.IO as TextIO



import System.Console.Ask (Ask, ask', askOptional', askOrElse', defaultBehaviour, runAsk)



main :: IO ()

main = runAsk defaultBehaviour $ do

    name              <- ask'         "What is your name?"               "Text> " :: Ask Text

    age               <- askOptional' "How old are you?"                 "Int > " :: Ask (Maybe Int)

    needNotifications <- askOrElse'   "Do you need notifications?" False "Y/N > " :: Ask Bool



    liftIO $ do

        TextIO.putStrLn ("Name: " <> name)

        TextIO.putStrLn ("Age: " <> Text.show age)

        TextIO.putStrLn ("Need notifications: " <> Text.show needNotifications)

What is your name?
Text> Toma Sasaki

How old are you?
Int > 18

Do you need notifications? (Default: False)
Y/N > True

Name: "Toma Sasaki"
Age: 18
Need notifications: True

import Control.Monad.IO.Class (liftIO)

import Data.Text (Text)

import qualified Data.Text as Text

import qualified Data.Text.IO as TextIO



import System.Console.Ask (Ask, ask, askOptional, askOrElse, defaultBehaviour, runAsk, withBehaviour)

import System.Console.Ask.Behaviour (DefaultValueStyle (..), defaultValueStyle, invalidInputErrorMsg, set)



main :: IO ()

main = runAsk defaultBehaviour $ do

    let customBehaviour1 = set invalidInputErrorMsg (Just "??????") defaultBehaviour

        customBehaviour2 = set defaultValueStyle OnNewline defaultBehaviour



    name              <- ask "What is your name?" :: Ask Text

    age               <- withBehaviour customBehaviour1 (askOptional "How old are you?")                 :: Ask (Maybe Int)

    needNotifications <- withBehaviour customBehaviour2 (askOrElse   "Do you need notifications?" False) :: Ask Bool



    liftIO $ do

        TextIO.putStrLn ("Name: " <> name)

        TextIO.putStrLn ("Age: " <> Text.show age)

        TextIO.putStrLn ("Need notifications: " <> Text.show needNotifications)

What is your name?
> Toma Sasaki

How old are you?
> a
??????

How old are you?
> 18

Do you need notifications?
Default: False
> True

Name: "Toma Sasaki"
Age: 18
Need notifications: True