diff options
Diffstat (limited to 'lib/Language/Haskell/Stylish/Util.hs')
| -rw-r--r-- | lib/Language/Haskell/Stylish/Util.hs | 126 |
1 files changed, 103 insertions, 23 deletions
diff --git a/lib/Language/Haskell/Stylish/Util.hs b/lib/Language/Haskell/Stylish/Util.hs index 9883f4b..1d35a03 100644 --- a/lib/Language/Haskell/Stylish/Util.hs +++ b/lib/Language/Haskell/Stylish/Util.hs @@ -1,8 +1,8 @@ -------------------------------------------------------------------------------- +{-# LANGUAGE LambdaCase #-} +{-# LANGUAGE PatternGuards #-} module Language.Haskell.Stylish.Util - ( nameToString - , isOperator - , indent + ( indent , padRight , everything , infoPoints @@ -13,22 +13,35 @@ module Language.Haskell.Stylish.Util , wrapMaybe , wrapRestMaybe + -- * Extra list functions , withHead , withInit , withTail , withLast + , flagEnds + + , toRealSrcSpan + + , traceOutputable + , traceOutputableM + + , unguardedRhsBody + , rhsBody + + , getGuards ) where -------------------------------------------------------------------------------- -import Control.Arrow ((&&&), (>>>)) -import Data.Char (isAlpha, isSpace) +import Data.Char (isSpace) import Data.Data (Data) import qualified Data.Generics as G -import Data.Maybe (fromMaybe, listToMaybe, - maybeToList) +import Data.Maybe (maybeToList) import Data.Typeable (cast) -import qualified Language.Haskell.Exts as H +import Debug.Trace (trace) +import qualified GHC.Hs as Hs +import qualified Outputable +import qualified SrcLoc as S -------------------------------------------------------------------------------- @@ -36,18 +49,6 @@ import Language.Haskell.Stylish.Step -------------------------------------------------------------------------------- -nameToString :: H.Name l -> String -nameToString (H.Ident _ str) = str -nameToString (H.Symbol _ str) = str - - --------------------------------------------------------------------------------- -isOperator :: H.Name l -> Bool -isOperator = fromMaybe False - . (fmap (not . isAlpha) . listToMaybe) - . nameToString - --------------------------------------------------------------------------------- indent :: Int -> String -> String indent len = (indentPrefix len ++) @@ -68,8 +69,16 @@ everything = G.everything (++) (maybeToList . cast) -------------------------------------------------------------------------------- -infoPoints :: H.SrcSpanInfo -> [((Int, Int), (Int, Int))] -infoPoints = H.srcInfoPoints >>> map (H.srcSpanStart &&& H.srcSpanEnd) +infoPoints :: [S.Located pass] -> [((Int, Int), (Int, Int))] +infoPoints = fmap (helper . S.getLoc) + where + helper :: S.SrcSpan -> ((Int, Int), (Int, Int)) + helper (S.RealSrcSpan s) = do + let + start = S.realSrcSpanStart s + end = S.realSrcSpanEnd s + ((S.srcLocLine start, S.srcLocCol start), (S.srcLocLine end, S.srcLocCol end)) + helper _ = ((-1,-1), (-1,-1)) -------------------------------------------------------------------------------- @@ -117,7 +126,7 @@ noWrap :: String -- ^ Leading string -> Lines -- ^ Resulting lines noWrap leading _ind = noWrap' leading where - noWrap' ss [] = [ss] + noWrap' ss [] = [ss] noWrap' ss (str:strs) = noWrap' (ss ++ " " ++ str) strs @@ -181,7 +190,78 @@ withInit _ [] = [] withInit _ [x] = [x] withInit f (x : xs) = f x : withInit f xs + -------------------------------------------------------------------------------- withTail :: (a -> a) -> [a] -> [a] withTail _ [] = [] withTail f (x : xs) = x : map f xs + + + +-------------------------------------------------------------------------------- +-- | Utility for traversing through a list and knowing when you're at the +-- first and last element. +flagEnds :: [a] -> [(a, Bool, Bool)] +flagEnds = \case + [] -> [] + [x] -> [(x, True, True)] + x : y : zs -> (x, True, False) : go (y : zs) + where + go (x : y : zs) = (x, False, False) : go (y : zs) + go [x] = [(x, False, True)] + go [] = [] + + +-------------------------------------------------------------------------------- +traceOutputable :: Outputable.Outputable a => String -> a -> b -> b +traceOutputable title x = + trace (title ++ ": " ++ (Outputable.showSDocUnsafe $ Outputable.ppr x)) + + +-------------------------------------------------------------------------------- +traceOutputableM :: (Outputable.Outputable a, Monad m) => String -> a -> m () +traceOutputableM title x = traceOutputable title x $ pure () + + +-------------------------------------------------------------------------------- +-- take the (Maybe) RealSrcSpan out of the SrcSpan +toRealSrcSpan :: S.SrcSpan -> Maybe S.RealSrcSpan +toRealSrcSpan (S.RealSrcSpan s) = Just s +toRealSrcSpan _ = Nothing + + +-------------------------------------------------------------------------------- +-- Utility: grab the body out of guarded RHSs if it's a single unguarded one. +unguardedRhsBody :: Hs.GRHSs Hs.GhcPs a -> Maybe a +unguardedRhsBody (Hs.GRHSs _ [grhs] _) + | Hs.GRHS _ [] body <- S.unLoc grhs = Just body +unguardedRhsBody _ = Nothing + + +-- Utility: grab the body out of guarded RHSs +rhsBody :: Hs.GRHSs Hs.GhcPs a -> Maybe a +rhsBody (Hs.GRHSs _ [grhs] _) + | Hs.GRHS _ _ body <- S.unLoc grhs = Just body +rhsBody _ = Nothing + + +-------------------------------------------------------------------------------- +-- get guards in a guarded rhs of a Match +getGuards :: Hs.Match Hs.GhcPs (Hs.LHsExpr Hs.GhcPs) -> [Hs.GuardLStmt Hs.GhcPs] +getGuards (Hs.Match _ _ _ grhss) = + let + lgrhs = getLocGRHS grhss -- [] + grhs = map S.unLoc lgrhs + in + concatMap getGuardLStmts grhs +getGuards (Hs.XMatch x) = Hs.noExtCon x + + +getLocGRHS :: Hs.GRHSs Hs.GhcPs (Hs.LHsExpr Hs.GhcPs) -> [Hs.LGRHS Hs.GhcPs (Hs.LHsExpr Hs.GhcPs)] +getLocGRHS (Hs.GRHSs _ guardeds _) = guardeds +getLocGRHS (Hs.XGRHSs x) = Hs.noExtCon x + + +getGuardLStmts :: Hs.GRHS Hs.GhcPs (Hs.LHsExpr Hs.GhcPs) -> [Hs.GuardLStmt Hs.GhcPs] +getGuardLStmts (Hs.GRHS _ guards _) = guards +getGuardLStmts (Hs.XGRHS x) = Hs.noExtCon x |