elna/lib/Language/Elna/CommandLine.hs

{- This Source Code Form is subject to the terms of the Mozilla Public License,
   v. 2.0. If a copy of the MPL was not distributed with this file, You can
   obtain one at https://mozilla.org/MPL/2.0/. -}

module Language.Elna.CommandLine
    ( CommandLine(..)
    , commandLine
    , execParser
    ) where

import Options.Applicative
    ( Parser
    , ParserInfo(..)
    , argument
    , execParser
    , fullDesc
    , help
    , helper
    , info
    , long
    , metavar
    , optional
    , progDesc
    , short
    , str
    , strOption
    )
import Control.Applicative ((<**>))

data CommandLine = CommandLine
    { input :: FilePath
    , output :: Maybe FilePath
    } deriving (Eq, Show)

parser :: Parser CommandLine
parser = CommandLine
    <$> argument str inFile
    <*> optional (strOption outFile)
  where
    inFile = metavar "INFILE" <> help "Input file."
    outFile = long "output"
        <> short 'o'
        <> metavar "OUTFILE"
        <> help "Output file."

commandLine :: ParserInfo CommandLine
commandLine = info (parser <**> helper)
    $ fullDesc <> progDesc "Elna compiler."