{-# LANGUAGE NoImplicitPrelude #-}

module Stack.Options.GhcVariantParser where

import Options.Applicative

import Options.Applicative.Types (readerAsk)

import Stack.Prelude

import Stack.Options.Utils

import Stack.Types.Config

-- | GHC variant parser

ghcVariantParser :: Bool -> Parser GHCVariant

ghcVariantParser hide =

option

readGHCVariant

(long "ghc-variant" <> metavar "VARIANT" <>

help

"Specialized GHC variant, e.g. integersimple (incompatible with --system-ghc)" <>

hideMods hide

)

where

readGHCVariant = do

s <- readerAsk

case parseGHCVariant s of

Left e -> readerError (show e)

Right v -> return v