module Language.Haskell.Tools.Refactor.ListOperations where
import Control.Reference
import Data.List (findIndices)
import Language.Haskell.Tools.AST
import Language.Haskell.Tools.AST.Rewrite (AnnList)
import Language.Haskell.Tools.Transform (srcTmpDefaultSeparator, srcTmpSeparators, srcTmpIndented)
filterList :: (Ann e dom SrcTemplateStage -> Bool) -> AnnList e dom -> AnnList e dom
filterList pred = filterListIndexed (const pred)
filterListIndexed :: (Int -> Ann e dom SrcTemplateStage -> Bool) -> AnnList e dom -> AnnList e dom
filterListIndexed pred (AnnListG (NodeInfo sema src) elems)
= AnnListG (NodeInfo sema (srcTmpIndented .- fmap filterIndents $ srcTmpSeparators .- filterSeparators $ src)) filteredElems
where elementsKept = findIndices (uncurry pred) (zip [0..] elems)
filteredElems = sublist elementsKept elems
filterIndents = sublist elementsKept
filterSeparators = take (length elementsKept 1) . sublist elementsKept
sublist :: [Int] -> [a] -> [a]
sublist = sublist' 0
where sublist' i [] _ = []
sublist' i _ [] = []
sublist' i (ind:more) (e:rest)
| i == ind = e : sublist' (i+1) more rest
| otherwise = sublist' (i+1) (ind:more) rest
insertWhere :: Bool -> Ann e dom SrcTemplateStage -> (Maybe (Ann e dom SrcTemplateStage) -> Bool)
-> (Maybe (Ann e dom SrcTemplateStage) -> Bool) -> AnnList e dom
-> AnnList e dom
insertWhere indented e before after al
= let index = insertIndex before after (al ^? annList)
in case index of
Nothing -> al
Just ind -> annListElems .- insertAt ind e
$ (if isEmptyAnnList then id else annListAnnot&sourceInfo .- setIndented ind . addDefaultSeparator ind)
$ al
where setIndented i = srcTmpIndented .- fmap (insertAt i indented)
addDefaultSeparator i al = srcTmpSeparators .- insertAt i (al ^. srcTmpDefaultSeparator) $ al
insertAt n e ls = let (bef,aft) = splitAt n ls in bef ++ [e] ++ aft
isEmptyAnnList = (null :: [x] -> Bool) $ (al ^? annList)
insertIndex :: (Maybe (Ann e dom SrcTemplateStage) -> Bool) -> (Maybe (Ann e dom SrcTemplateStage) -> Bool) -> [Ann e dom SrcTemplateStage] -> Maybe Int
insertIndex before after []
| before Nothing && after Nothing = Just 0
| otherwise = Nothing
insertIndex before after list@(first:_)
| before Nothing && after (Just first) = Just 0
| otherwise = (+1) <$> insertIndex' before after list
where insertIndex' before after (curr:rest@(next:_))
| before (Just curr) && after (Just next) = Just 0
| otherwise = (+1) <$> insertIndex' before after rest
insertIndex' before after (curr:[])
| before (Just curr) && after Nothing = Just 0
| otherwise = Nothing
insertIndex' before after []
| before Nothing && after Nothing = Just 0
| otherwise = Nothing
zipWithSeparators :: AnnList e dom -> [(String, Ann e dom SrcTemplateStage)]
zipWithSeparators (AnnListG (NodeInfo _ src) elems)
| [] <- src ^. srcTmpSeparators
= zip ("" : repeat (src ^. srcTmpDefaultSeparator)) elems
| otherwise
= zip ("" : seps ++ repeat (last seps)) elems
where seps = src ^. srcTmpSeparators