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--------------------------------------------------------------------------------
{-# LANGUAGE RecordWildCards #-}
{-# LANGUAGE TypeFamilies #-}
module Language.Haskell.Stylish.Step.SimpleAlign
( Config (..)
, Align (..)
, defaultConfig
, step
) where
--------------------------------------------------------------------------------
import Data.Either (partitionEithers)
import Data.Foldable (toList)
import Data.List (foldl', foldl1', sortOn)
import Data.Maybe (fromMaybe)
import qualified GHC.Hs as Hs
import qualified GHC.Parser.Annotation as GHC
import qualified GHC.Types.SrcLoc as GHC
--------------------------------------------------------------------------------
import Language.Haskell.Stylish.Align
import qualified Language.Haskell.Stylish.Editor as Editor
import Language.Haskell.Stylish.GHC
import Language.Haskell.Stylish.Module
import Language.Haskell.Stylish.Step
import Language.Haskell.Stylish.Util
--------------------------------------------------------------------------------
data Config = Config
{ cCases :: Align
, cTopLevelPatterns :: Align
, cRecords :: Align
, cMultiWayIf :: Align
} deriving (Show)
data Align
= Always
| Adjacent
| Never
deriving (Eq, Show)
defaultConfig :: Config
defaultConfig = Config
{ cCases = Always
, cTopLevelPatterns = Always
, cRecords = Always
, cMultiWayIf = Always
}
groupAlign :: Align -> [Alignable GHC.RealSrcSpan] -> [[Alignable GHC.RealSrcSpan]]
groupAlign a xs = case a of
Never -> []
Adjacent -> byLine . sortOn (GHC.srcSpanStartLine . aLeft) $ xs
Always -> [xs]
where
byLine = map toList . groupByLine aLeft
--------------------------------------------------------------------------------
type Record = [GHC.LocatedA (Hs.ConDeclField Hs.GhcPs)]
--------------------------------------------------------------------------------
records :: Module -> [Record]
records modu = do
let decls = map GHC.unLoc (Hs.hsmodDecls (GHC.unLoc modu))
tyClDecls = [ tyClDecl | Hs.TyClD _ tyClDecl <- decls ]
dataDecls = [ d | d@(Hs.DataDecl _ _ _ _ _) <- tyClDecls ]
dataDefns = map Hs.tcdDataDefn dataDecls
d@Hs.ConDeclH98 {} <- GHC.unLoc <$> concatMap getConDecls dataDefns
case Hs.con_args d of
Hs.RecCon rec -> [GHC.unLoc rec]
_ -> []
--------------------------------------------------------------------------------
recordToAlignable :: Config -> Record -> [[Alignable GHC.RealSrcSpan]]
recordToAlignable conf = groupAlign (cRecords conf) . fromMaybe [] . traverse fieldDeclToAlignable
--------------------------------------------------------------------------------
fieldDeclToAlignable
:: GHC.LocatedA (Hs.ConDeclField Hs.GhcPs) -> Maybe (Alignable GHC.RealSrcSpan)
fieldDeclToAlignable (GHC.L matchLoc (Hs.ConDeclField _ names ty _)) = do
matchPos <- GHC.srcSpanToRealSrcSpan $ GHC.locA matchLoc
leftPos <- GHC.srcSpanToRealSrcSpan $ GHC.getLocA $ last names
tyPos <- GHC.srcSpanToRealSrcSpan $ GHC.getLocA ty
Just $ Alignable
{ aContainer = matchPos
, aLeft = leftPos
, aRight = tyPos
, aRightLead = length ":: "
}
--------------------------------------------------------------------------------
matchGroupToAlignable
:: Config
-> Hs.MatchGroup Hs.GhcPs (Hs.LHsExpr Hs.GhcPs)
-> [[Alignable GHC.RealSrcSpan]]
matchGroupToAlignable conf mg = cases' ++ patterns'
where
alts = Hs.mg_alts mg
(cases, patterns) = partitionEithers . fromMaybe [] $ traverse matchToAlignable (GHC.unLoc alts)
cases' = groupAlign (cCases conf) cases
patterns' = groupAlign (cTopLevelPatterns conf) patterns
--------------------------------------------------------------------------------
matchToAlignable
:: GHC.LocatedA (Hs.Match Hs.GhcPs (Hs.LHsExpr Hs.GhcPs))
-> Maybe (Either (Alignable GHC.RealSrcSpan) (Alignable GHC.RealSrcSpan))
matchToAlignable (GHC.L matchLoc m@(Hs.Match _ Hs.CaseAlt (GHC.L _ pats@(_ : _)) grhss)) = do
let patsLocs = map GHC.getLocA pats
pat = last patsLocs
guards = getGuards m
guardsLocs = map GHC.getLocA guards
left = foldl' GHC.combineSrcSpans pat guardsLocs
body <- rhsBody grhss
matchPos <- GHC.srcSpanToRealSrcSpan $ GHC.locA matchLoc
leftPos <- GHC.srcSpanToRealSrcSpan left
rightPos <- GHC.srcSpanToRealSrcSpan $ GHC.getLocA body
Just . Left $ Alignable
{ aContainer = matchPos
, aLeft = leftPos
, aRight = rightPos
, aRightLead = length "-> "
}
matchToAlignable (GHC.L matchLoc (Hs.Match _ (Hs.FunRhs name _ _ _) (GHC.L _ pats@(_ : _)) grhss)) = do
body <- unguardedRhsBody grhss
let patsLocs = map GHC.getLocA pats
nameLoc = GHC.getLocA name
left = last (nameLoc : patsLocs)
bodyLoc = GHC.getLocA body
matchPos <- GHC.srcSpanToRealSrcSpan $ GHC.locA matchLoc
leftPos <- GHC.srcSpanToRealSrcSpan left
bodyPos <- GHC.srcSpanToRealSrcSpan bodyLoc
Just . Right $ Alignable
{ aContainer = matchPos
, aLeft = leftPos
, aRight = bodyPos
, aRightLead = length "= "
}
matchToAlignable (GHC.L _ (Hs.Match _ _ _ _)) = Nothing
--------------------------------------------------------------------------------
multiWayIfToAlignable
:: Config
-> Hs.LHsExpr Hs.GhcPs
-> [[Alignable GHC.RealSrcSpan]]
multiWayIfToAlignable conf (GHC.L _ (Hs.HsMultiIf _ grhss)) =
groupAlign (cMultiWayIf conf) as
where
as = fromMaybe [] $ traverse grhsToAlignable grhss
multiWayIfToAlignable _conf _ = []
--------------------------------------------------------------------------------
grhsToAlignable
:: GHC.GenLocated (GHC.EpAnnCO) (Hs.GRHS Hs.GhcPs (Hs.LHsExpr Hs.GhcPs))
-> Maybe (Alignable GHC.RealSrcSpan)
grhsToAlignable (GHC.L (GHC.EpAnn (GHC.EpaSpan grhsloc) _ _ ) (Hs.GRHS _ guards@(_ : _) body)) = do
let guardsLocs = map GHC.getLocA guards
bodyLoc = GHC.getLocA $ body
left = foldl1' GHC.combineSrcSpans guardsLocs
matchPos <- GHC.srcSpanToRealSrcSpan grhsloc
leftPos <- GHC.srcSpanToRealSrcSpan left
bodyPos <- GHC.srcSpanToRealSrcSpan bodyLoc
Just $ Alignable
{ aContainer = matchPos
, aLeft = leftPos
, aRight = bodyPos
, aRightLead = length "-> "
}
grhsToAlignable (GHC.L _ _) = Nothing
--------------------------------------------------------------------------------
step :: Maybe Int -> Config -> Step
step maxColumns config = makeStep "Cases" $ \ls module' ->
let changes
:: (Module -> [a])
-> (a -> [[Alignable GHC.RealSrcSpan]])
-> Editor.Edits
changes search toAlign = mconcat $ do
item <- search module'
pure $ foldMap (align maxColumns) (toAlign item)
configured :: Editor.Edits
configured =
changes records (recordToAlignable config) <>
changes everything (matchGroupToAlignable config) <>
changes everything (multiWayIfToAlignable config) in
Editor.apply configured ls
|
