Merge pull request #141 from alanz/master

Exposing lower level API using GhcMonad

Language/Haskell/GhcMod/ErrMsg.hs

@@ -21,6 +21,7 @@ import System.FilePath (normalise)
 
 ----------------------------------------------------------------
 
+-- | A means to read the log
 type LogReader = IO [String]
 
 ----------------------------------------------------------------

Language/Haskell/GhcMod/GHCApi.hs

@@ -57,9 +57,12 @@ importDirs = [".","..","../..","../../..","../../../..","../../../../.."]
 
 data Build = CabalPkg | SingleFile deriving Eq
 
-initializeFlagsWithCradle :: Options -> Cradle -> [GHCOption] -> Bool -> Ghc LogReader
+-- | Initialize the 'DynFlags' relating to the compilation of a single
+-- file or GHC session according to the 'Cradle' and 'Options'
+-- provided.
+initializeFlagsWithCradle :: GhcMonad m =>  Options -> Cradle -> [GHCOption] -> Bool -> m LogReader
 initializeFlagsWithCradle opt cradle ghcOptions logging
-  | cabal     = withCabal ||> withoutCabal
+  | cabal     = withCabal |||> withoutCabal
   | otherwise = withoutCabal
   where
     cabal = isJust $ cradleCabalFile cradle
@@ -71,13 +74,13 @@ initializeFlagsWithCradle opt cradle ghcOptions logging
 
 ----------------------------------------------------------------
 
-initSession :: Build
+initSession :: GhcMonad m => Build
             -> Options
             -> [GHCOption]
             -> [IncludeDir]
             -> Maybe [Package]
             -> Bool
-            -> Ghc LogReader
+            -> m LogReader
 initSession build opt cmdOpts idirs mDepPkgs logging = do
     dflags0 <- getSessionDynFlags
     (dflags1,readLog) <- setupDynamicFlags dflags0
@@ -92,7 +95,7 @@ initSession build opt cmdOpts idirs mDepPkgs logging = do
 
 ----------------------------------------------------------------
 
-initializeFlags :: Options -> Ghc ()
+initializeFlags :: GhcMonad m => Options -> m ()
 initializeFlags opt = do
     dflags0 <- getSessionDynFlags
     dflags1 <- modifyFlagsWithOpts dflags0 $ ghcOpts opt
@@ -127,22 +130,22 @@ setFastOrNot dflags Fast = dflags {
   , hscTarget = HscNothing
   }
 
-setSlowDynFlags :: Ghc ()
+setSlowDynFlags :: GhcMonad m => m ()
 setSlowDynFlags = (flip setFastOrNot Slow <$> getSessionDynFlags)
                   >>= void . setSessionDynFlags
 
--- To check TH, a session module graph is necessary.
+-- | To check TH, a session module graph is necessary.
 -- "load" sets a session module graph using "depanal".
 -- But we have to set "-fno-code" to DynFlags before "load".
 -- So, this is necessary redundancy.
-checkSlowAndSet :: Ghc ()
+checkSlowAndSet :: GhcMonad m => m ()
 checkSlowAndSet = do
     fast <- canCheckFast <$> depanal [] False
     unless fast setSlowDynFlags
 
 ----------------------------------------------------------------
 
-modifyFlagsWithOpts :: DynFlags -> [String] -> Ghc DynFlags
+modifyFlagsWithOpts :: GhcMonad m => DynFlags -> [String] -> m DynFlags
 modifyFlagsWithOpts dflags cmdOpts =
     tfst <$> parseDynamicFlags dflags (map noLoc cmdOpts)
   where
@@ -150,6 +153,7 @@ modifyFlagsWithOpts dflags cmdOpts =
 
 ----------------------------------------------------------------
 
+-- | Set the file that GHC will load / compile
 setTargetFile :: (GhcMonad m) => String -> m ()
 setTargetFile file = do
     target <- guessTarget file Nothing
@@ -157,6 +161,7 @@ setTargetFile file = do
 
 ----------------------------------------------------------------
 
+-- | Return the 'DynFlags' currently in use in the GHC session
 getDynamicFlags :: IO DynFlags
 getDynamicFlags = runGhc (Just libdir) getSessionDynFlags
 

Language/Haskell/GhcMod/GHCChoice.hs

@@ -12,6 +12,9 @@ import GHC
 (||>) :: Ghc a -> Ghc a -> Ghc a
 x ||> y = x `gcatch` (\(_ :: IOException) -> y)
 
+(|||>) :: GhcMonad m => m a -> m a -> m a
+x |||> y = x `gcatch` (\(_ :: IOException) -> y)
+
 ----------------------------------------------------------------
 
 {-| Go to the next 'Ghc' monad by throwing 'AltGhcgoNext'.

Language/Haskell/GhcMod/Internal.hs

@@ -0,0 +1,16 @@
+-- | Low level access to the ghc-mod library.
+
+module Language.Haskell.GhcMod.Internal (
+  -- * Low level access
+    LogReader
+  , GHCOption
+  , initializeFlagsWithCradle
+  , setTargetFile
+  , checkSlowAndSet
+  , getDynamicFlags
+  ) where
+
+import Language.Haskell.GhcMod.ErrMsg
+import Language.Haskell.GhcMod.GHCApi
+import Language.Haskell.GhcMod.Types
+

Language/Haskell/GhcMod/Types.hs

@@ -84,7 +84,9 @@ data Cradle = Cradle {
 
 ----------------------------------------------------------------
 
+-- | A single GHC option, as it would appear on the command line
 type GHCOption  = String
+
 type IncludeDir = FilePath
 type Package    = String
 

ghc-mod.cabal

@@ -40,6 +40,7 @@ Library
   Default-Language:     Haskell2010
   GHC-Options:          -Wall
   Exposed-Modules:      Language.Haskell.GhcMod
+                        Language.Haskell.GhcMod.Internal
   Other-Modules:        Language.Haskell.GhcMod.Browse
                         Language.Haskell.GhcMod.CabalApi
                         Language.Haskell.GhcMod.Check