ghc-mod/Language/Haskell/GhcMod/Info.hs
2014-06-09 10:30:33 +02:00

139 lines
5.0 KiB
Haskell

{-# LANGUAGE TupleSections, FlexibleInstances, Rank2Types #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Language.Haskell.GhcMod.Info (
infoExpr
, info
, typeExpr
, types
) where
import Control.Applicative ((<$>))
import CoreMonad (liftIO)
import CoreUtils (exprType)
import Data.Function (on)
import Data.Generics
import Data.List (sortBy)
import Data.Maybe (catMaybes, fromMaybe)
import Data.Ord as O
import Exception (ghandle, SomeException(..))
import GHC (Ghc, LHsBind, LHsExpr, LPat, Id, TypecheckedModule(..), DynFlags, SrcSpan, Type, Located, TypecheckedSource, GenLocated(L))
import qualified GHC as G
import GHC.SYB.Utils (Stage(TypeChecker), everythingStaged)
import Language.Haskell.GhcMod.Doc (showPage, showOneLine, getStyle)
import Language.Haskell.GhcMod.GHCApi
import Language.Haskell.GhcMod.Gap (HasType(..), setWarnTypedHoles, setDeferTypeErrors)
import qualified Language.Haskell.GhcMod.Gap as Gap
import Language.Haskell.GhcMod.Types
import Language.Haskell.GhcMod.Convert
import Outputable (PprStyle)
import TcHsSyn (hsPatType)
----------------------------------------------------------------
-- | Obtaining information of a target expression. (GHCi's info:)
infoExpr :: Options
-> Cradle
-> FilePath -- ^ A target file.
-> Expression -- ^ A Haskell expression.
-> IO String
infoExpr opt cradle file expr = withGHC' $ do
initializeFlagsWithCradle opt cradle
info opt file expr
-- | Obtaining information of a target expression. (GHCi's info:)
info :: Options
-> FilePath -- ^ A target file.
-> Expression -- ^ A Haskell expression.
-> Ghc String
info opt file expr = convert opt <$> ghandle handler body
where
body = inModuleContext file $ \dflag style -> do
sdoc <- Gap.infoThing expr
return $ showPage dflag style sdoc
handler (SomeException _) = return "Cannot show info"
----------------------------------------------------------------
instance HasType (LHsExpr Id) where
getType tcm e = do
hs_env <- G.getSession
mbe <- liftIO $ Gap.deSugar tcm e hs_env
return $ (G.getLoc e, ) <$> CoreUtils.exprType <$> mbe
instance HasType (LPat Id) where
getType _ (G.L spn pat) = return $ Just (spn, hsPatType pat)
----------------------------------------------------------------
-- | Obtaining type of a target expression. (GHCi's type:)
typeExpr :: Options
-> Cradle
-> FilePath -- ^ A target file.
-> Int -- ^ Line number.
-> Int -- ^ Column number.
-> IO String
typeExpr opt cradle file lineNo colNo = withGHC' $ do
initializeFlagsWithCradle opt cradle
types opt file lineNo colNo
-- | Obtaining type of a target expression. (GHCi's type:)
types :: Options
-> FilePath -- ^ A target file.
-> Int -- ^ Line number.
-> Int -- ^ Column number.
-> Ghc String
types opt file lineNo colNo = convert opt <$> ghandle handler body
where
body = inModuleContext file $ \dflag style -> do
modSum <- Gap.fileModSummary file
srcSpanTypes <- getSrcSpanType modSum lineNo colNo
return $ map (toTup dflag style) $ sortBy (cmp `on` fst) srcSpanTypes
handler (SomeException _) = return []
getSrcSpanType :: G.ModSummary -> Int -> Int -> Ghc [(SrcSpan, Type)]
getSrcSpanType modSum lineNo colNo = do
p <- G.parseModule modSum
tcm@TypecheckedModule{tm_typechecked_source = tcs} <- G.typecheckModule p
let bs = listifySpans tcs (lineNo, colNo) :: [LHsBind Id]
es = listifySpans tcs (lineNo, colNo) :: [LHsExpr Id]
ps = listifySpans tcs (lineNo, colNo) :: [LPat Id]
bts <- mapM (getType tcm) bs
ets <- mapM (getType tcm) es
pts <- mapM (getType tcm) ps
return $ catMaybes $ concat [ets, bts, pts]
listifySpans :: Typeable a => TypecheckedSource -> (Int, Int) -> [Located a]
listifySpans tcs lc = listifyStaged TypeChecker p tcs
where
p (L spn _) = G.isGoodSrcSpan spn && spn `G.spans` lc
listifyStaged :: Typeable r => Stage -> (r -> Bool) -> GenericQ [r]
listifyStaged s p = everythingStaged s (++) [] ([] `mkQ` (\x -> [x | p x]))
cmp :: SrcSpan -> SrcSpan -> Ordering
cmp a b
| a `G.isSubspanOf` b = O.LT
| b `G.isSubspanOf` a = O.GT
| otherwise = O.EQ
toTup :: DynFlags -> PprStyle -> (SrcSpan, Type) -> ((Int,Int,Int,Int),String)
toTup dflag style (spn, typ) = (fourInts spn, pretty dflag style typ)
fourInts :: SrcSpan -> (Int,Int,Int,Int)
fourInts = fromMaybe (0,0,0,0) . Gap.getSrcSpan
pretty :: DynFlags -> PprStyle -> Type -> String
pretty dflag style = showOneLine dflag style . Gap.typeForUser
----------------------------------------------------------------
inModuleContext :: FilePath -> (DynFlags -> PprStyle -> Ghc a) -> Ghc a
inModuleContext file action =
withDynFlags (setWarnTypedHoles . setDeferTypeErrors . setNoWaringFlags) $ do
setTargetFiles [file]
Gap.withContext $ do
dflag <- G.getSessionDynFlags
style <- getStyle
action dflag style