-- cabal-helper: Simple interface to Cabal's configuration state -- Copyright (C) 2015-2017 Daniel Gröber -- -- This program is free software: you can redistribute it and/or modify -- it under the terms of the GNU General Public License as published by -- the Free Software Foundation, either version 3 of the License, or -- (at your option) any later version. -- -- This program is distributed in the hope that it will be useful, -- but WITHOUT ANY WARRANTY; without even the implied warranty of -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -- GNU General Public License for more details. -- -- You should have received a copy of the GNU General Public License -- along with this program. If not, see . {-| Module : CabalHelper.Shared.Sandbox Description : Extracting information from @cabal.sandbox.config@ files License : GPL-3 -} module CabalHelper.Shared.Sandbox where import Control.Applicative import Data.Char import Data.Maybe import Data.List import Data.Version import System.FilePath import Prelude import qualified Data.Traversable as T import CabalHelper.Shared.Common -- | Get the path to the sandbox package-db in a project getSandboxPkgDb :: String -- ^ Cabal build platform, i.e. @buildPlatform@ -> Version -- ^ GHC version (@cProjectVersion@ is your friend) -> FilePath -- ^ Path to the cabal package root directory (containing the -- @cabal.sandbox.config@ file) -> IO (Maybe FilePath) getSandboxPkgDb platform ghcVer projdir = do mConf <- T.traverse readFile =<< mightExist (projdir "cabal.sandbox.config") return $ fixPkgDbVer <$> (extractSandboxDbDir =<< mConf) where fixPkgDbVer dir = case takeFileName dir == ghcSandboxPkgDbDir platform ghcVer of True -> dir False -> takeDirectory dir ghcSandboxPkgDbDir platform ghcVer ghcSandboxPkgDbDir :: String -> Version -> String ghcSandboxPkgDbDir platform ghcVer = platform ++ "-ghc-" ++ showVersion ghcVer ++ "-packages.conf.d" -- | Extract the sandbox package db directory from the cabal.sandbox.config -- file. Exception is thrown if the sandbox config file is broken. extractSandboxDbDir :: String -> Maybe FilePath extractSandboxDbDir conf = extractValue <$> parse conf where key = "package-db:" keyLen = length key parse = listToMaybe . filter (key `isPrefixOf`) . lines extractValue = CabalHelper.Shared.Sandbox.dropWhileEnd isSpace . dropWhile isSpace . drop keyLen -- dropWhileEnd is not provided prior to base 4.5.0.0. dropWhileEnd :: (a -> Bool) -> [a] -> [a] dropWhileEnd p = foldr (\x xs -> if p x && null xs then [] else x : xs) []