ghc-mod/Language/Haskell/GhcMod/Info.hs
2014-04-27 21:26:03 +09:00

137 lines
4.9 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(..), setDeferTypeErrors)
import qualified Language.Haskell.GhcMod.Gap as Gap
import Language.Haskell.GhcMod.Types
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 [noWaringOption]
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 [noWaringOption]
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 setDeferTypeErrors $ do
setTargetFiles [file]
Gap.withContext $ do
dflag <- G.getSessionDynFlags
style <- getStyle
action dflag style