ghc-mod/GhcMod/Browse.hs
2017-01-12 17:05:47 +01:00

170 lines
5.7 KiB
Haskell

{-# LANGUAGE CPP #-}
module GhcMod.Browse (
browse,
BrowseOpts(..)
) where
import Safe
import Control.Applicative
import Control.Exception (SomeException(..))
import Data.Char
import Data.List
import Data.Maybe
import FastString
import GHC
import HscTypes
import qualified GHC as G
import Language.Haskell.GhcMod.Convert
import Language.Haskell.GhcMod.Doc (showPage, styleUnqualified)
import Language.Haskell.GhcMod.Gap as Gap
import Language.Haskell.GhcMod.Types
import Language.Haskell.GhcMod.Monad
import Language.Haskell.GhcMod.Logging
import Name (getOccString)
import Outputable
import TyCon (isAlgTyCon)
import Type (dropForAlls, splitFunTy_maybe, mkFunTy, isPredTy)
import Exception (ExceptionMonad, ghandle)
import Prelude
#if __GLASGOW_HASKELL__ >= 800
import PatSyn (pprPatSynType)
#endif
----------------------------------------------------------------
-- | Getting functions, classes, etc from a module.
browse :: forall m. IOish m
=> BrowseOpts -- ^ Configuration parameters
-> String -- ^ A module name. (e.g. \"Data.List\", "base:Prelude")
-> GhcModT m String
browse opts pkgmdl = do
convert' . sort =<< go
where
-- TODO: Add API to Gm.Target to check if module is home module without
-- bringing up a GHC session as well then this can be made a lot cleaner
go = ghandle (\ex@(SomeException _) -> logException ex >> return []) $ do
goPkgModule `G.gcatch` (\(SomeException _) -> goHomeModule)
logException ex =
gmLog GmException "browse" $ showToDoc ex
goPkgModule = do
runGmPkgGhc $
processExports opts =<< tryModuleInfo =<< G.findModule mdlname mpkgid
goHomeModule = runGmlT [Right mdlname] $ do
processExports opts =<< tryModuleInfo =<< G.findModule mdlname Nothing
tryModuleInfo m = fromJustNote "browse, tryModuleInfo" <$> G.getModuleInfo m
(mpkg, mdl) = splitPkgMdl pkgmdl
mdlname = G.mkModuleName mdl
mpkgid = mkFastString <$> mpkg
-- |
--
-- >>> splitPkgMdl "base:Prelude"
-- (Just "base","Prelude")
-- >>> splitPkgMdl "Prelude"
-- (Nothing,"Prelude")
splitPkgMdl :: String -> (Maybe String,String)
splitPkgMdl pkgmdl =
case break (==':') pkgmdl of
(mdl, "") -> (Nothing, mdl)
(pkg, _:mdl) -> (Just pkg, mdl)
-- Haskell 2010:
-- small -> ascSmall | uniSmall | _
-- ascSmall -> a | b | ... | z
-- uniSmall -> any Unicode lowercase letter
-- varid -> (small {small | large | digit | ' })
isNotOp :: String -> Bool
isNotOp (h:_) = isAlpha h || (h == '_')
isNotOp _ = error "isNotOp"
processExports :: (G.GhcMonad m, MonadIO m, ExceptionMonad m)
=> BrowseOpts -> ModuleInfo -> m [String]
processExports opt minfo = do
let
removeOps
| optBrowseOperators opt = id
| otherwise = filter (isNotOp . getOccString)
mapM (showExport opt minfo) $ removeOps $ G.modInfoExports minfo
showExport :: forall m. (G.GhcMonad m, MonadIO m, ExceptionMonad m)
=> BrowseOpts -> ModuleInfo -> Name -> m String
showExport opt minfo e = do
mtype' <- mtype
return $ concat $ catMaybes [mqualified, Just $ formatOp $ getOccString e, mtype']
where
mqualified = (G.moduleNameString (G.moduleName $ G.nameModule e) ++ ".") `justIf` optBrowseQualified opt
mtype :: m (Maybe String)
mtype
| optBrowseDetailed opt || optBrowseParents opt = do
tyInfo <- G.modInfoLookupName minfo e
-- If nothing found, load dependent module and lookup global
tyResult <- maybe (inOtherModule e) (return . Just) tyInfo
dflag <- G.getSessionDynFlags
let sig = do
typeName <- tyResult >>= showThing dflag
(" :: " ++ typeName) `justIf` optBrowseDetailed opt
let parent = do
thing <- fmap getOccString $ tyResult >>= tyThingParent_maybe
(" -- from:" ++ thing) `justIf` optBrowseParents opt
return $ case concat $ catMaybes [sig, parent] of
[] -> Nothing
x -> Just x
| otherwise = return Nothing
formatOp nm
| null nm = error "formatOp"
| isNotOp nm = nm
| otherwise = "(" ++ nm ++ ")"
inOtherModule :: Name -> m (Maybe TyThing)
inOtherModule nm = do
G.getModuleInfo (G.nameModule nm) >> G.lookupGlobalName nm
justIf :: a -> Bool -> Maybe a
justIf x True = Just x
justIf _ False = Nothing
showThing :: DynFlags -> TyThing -> Maybe String
showThing dflag tything = showThing' dflag (fromTyThing tything)
showThing' :: DynFlags -> GapThing -> Maybe String
showThing' dflag (GtA a) = Just $ formatType dflag a
showThing' _ (GtT t) = unwords . toList <$> tyType t
where
toList t' = t' : getOccString t : map getOccString (G.tyConTyVars t)
#if __GLASGOW_HASKELL__ >= 800
showThing' dflag (GtPatSyn p) = Just $ showSDoc dflag $ pprPatSynType p
#endif
showThing' _ _ = Nothing
formatType :: DynFlags -> Type -> String
formatType dflag a = showOutputable dflag (removeForAlls a)
tyType :: TyCon -> Maybe String
tyType typ
| isAlgTyCon typ
&& not (G.isNewTyCon typ)
&& not (G.isClassTyCon typ) = Just "data"
| G.isNewTyCon typ = Just "newtype"
| G.isClassTyCon typ = Just "class"
| Gap.isSynTyCon typ = Just "type"
| otherwise = Nothing
removeForAlls :: Type -> Type
removeForAlls ty = removeForAlls' ty' tty'
where
ty' = dropForAlls ty
tty' = splitFunTy_maybe ty'
removeForAlls' :: Type -> Maybe (Type, Type) -> Type
removeForAlls' ty Nothing = ty
removeForAlls' ty (Just (pre, ftype))
| isPredTy pre = mkFunTy pre (dropForAlls ftype)
| otherwise = ty
showOutputable :: Outputable a => DynFlags -> a -> String
showOutputable dflag = unwords . lines . showPage dflag styleUnqualified . ppr