ghc-mod/Language/Haskell/GhcMod/Info.hs

64 lines
2.3 KiB
Haskell

module Language.Haskell.GhcMod.Info (
info
, types
) where
import Control.Applicative ((<$>))
import Data.Function (on)
import Data.List (sortBy)
import Data.Maybe (catMaybes)
import Exception (ghandle, SomeException(..))
import GHC (GhcMonad, LHsBind, LHsExpr, LPat, Id, TypecheckedModule(..), SrcSpan, Type)
import qualified GHC as G
import Language.Haskell.GhcMod.Doc (showPage)
import Language.Haskell.GhcMod.Gap (HasType(..))
import qualified Language.Haskell.GhcMod.Gap as Gap
import Language.Haskell.GhcMod.Monad
import Language.Haskell.GhcMod.SrcUtils
import Language.Haskell.GhcMod.Types
import Language.Haskell.GhcMod.Convert
----------------------------------------------------------------
-- | Obtaining information of a target expression. (GHCi's info:)
info :: FilePath -- ^ A target file.
-> Expression -- ^ A Haskell expression.
-> GhcMod String
info file expr = do
opt <- options
convert opt <$> 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"
----------------------------------------------------------------
-- | Obtaining type of a target expression. (GHCi's type:)
types :: FilePath -- ^ A target file.
-> Int -- ^ Line number.
-> Int -- ^ Column number.
-> GhcMod String
types file lineNo colNo = do
opt <- options
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 :: GhcMonad m => G.ModSummary -> Int -> Int -> m [(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]