Options.hs

-- Copyright (c) 2019 The DAML Authors. All rights reserved.
-- SPDX-License-Identifier: Apache-2.0

{-# LANGUAGE RankNTypes #-}

-- | Options
module Development.IDE.Types.Options
  ( IdeOptions(..)
  , IdeReportProgress(..)
  , IdeDefer(..)
  , clientSupportsProgress
  , IdePkgLocationOptions(..)
  , defaultIdeOptions
  ) where

import Data.Maybe
import Development.Shake
import Development.IDE.GHC.Util
import           GHC hiding (parseModule, typecheckModule)
import           GhcPlugins                     as GHC hiding (fst3, (<>))
import qualified Language.Haskell.LSP.Types.Capabilities as LSP

data IdeOptions = IdeOptions
  { optPreprocessor :: GHC.ParsedSource -> ([(GHC.SrcSpan, String)], GHC.ParsedSource)
    -- ^ Preprocessor to run over all parsed source trees, generating a list of warnings
    --   along with a new parse tree.
  , optGhcSession :: IO (FilePath -> Action HscEnvEq)
    -- ^ Setup a GHC session for a given file, e.g. @Foo.hs@.
    --   The 'IO' will be called once, then the resulting function will be applied once per file.
    --   It is desirable that many files get the same 'HscEnvEq', so that more IDE features work.
    --   You should not use 'newCacheIO' to get that caching, because of
    --   https://github.com/ndmitchell/shake/issues/725.
  , optPkgLocationOpts :: IdePkgLocationOptions
    -- ^ How to locate source and @.hie@ files given a module name.
  , optExtensions :: [String]
    -- ^ File extensions to search for code, defaults to Haskell sources (including @.hs@)

  , optThreads :: Int
    -- ^ Number of threads to use. Use 0 for number of threads on the machine.
  , optShakeProfiling :: Maybe FilePath
    -- ^ Set to 'Just' to create a directory of profiling reports.
  , optReportProgress :: IdeReportProgress
    -- ^ Whether to report progress during long operations.
  , optLanguageSyntax :: String
    -- ^ the ```language to use
  , optNewColonConvention :: Bool
    -- ^ whether to use new colon convention
  , optDefer :: IdeDefer
    -- ^ Whether to defer type errors, typed holes and out of scope
    --   variables. Deferral allows the IDE to continue to provide
    --   features such as diagnostics and go-to-definition, in
    --   situations in which they would become unavailable because of
    --   the presence of type errors, holes or unbound variables.
  }

newtype IdeReportProgress = IdeReportProgress Bool
newtype IdeDefer          = IdeDefer          Bool

clientSupportsProgress :: LSP.ClientCapabilities -> IdeReportProgress
clientSupportsProgress caps = IdeReportProgress $ fromMaybe False $
    LSP._workDoneProgress =<< LSP._window (caps :: LSP.ClientCapabilities)

defaultIdeOptions :: IO (FilePath -> Action HscEnvEq) -> IdeOptions
defaultIdeOptions session = IdeOptions
    {optPreprocessor = (,) []
    ,optGhcSession = session
    ,optExtensions = ["hs", "lhs"]
    ,optPkgLocationOpts = defaultIdePkgLocationOptions
    ,optThreads = 0
    ,optShakeProfiling = Nothing
    ,optReportProgress = IdeReportProgress False
    ,optLanguageSyntax = "haskell"
    ,optNewColonConvention = False
    ,optDefer = IdeDefer True
    }


-- | The set of options used to locate files belonging to external packages.
data IdePkgLocationOptions = IdePkgLocationOptions
  { optLocateHieFile :: PackageConfig -> Module -> IO (Maybe FilePath)
  -- ^ Locate the HIE file for the given module. The PackageConfig can be
  -- used to lookup settings like importDirs.
  , optLocateSrcFile :: PackageConfig -> Module -> IO (Maybe FilePath)
  -- ^ Locate the source file for the given module. The PackageConfig can be
  -- used to lookup settings like importDirs. For DAML, we place them in the package DB.
  -- For cabal this could point somewhere in ~/.cabal/packages.
  }

defaultIdePkgLocationOptions :: IdePkgLocationOptions
defaultIdePkgLocationOptions = IdePkgLocationOptions f f
    where f _ _ = return Nothing