{-# LANGUAGE ScopedTypeVariables #-}
module Text.ABNF.Document.Operations where
import Control.Monad (join)
import Data.Maybe (catMaybes)
import qualified Data.Text as Text
import Text.ABNF.Document.Types
filterDocument :: forall a. (Document a -> Bool)
-> Document a
-> Maybe (Document a)
filterDocument pred term@(Terminal _) | pred term = Just term
| otherwise = Nothing
filterDocument pred doc@(Document ident conts)
| pred doc = Just . Document ident $ (catMaybes . fmap (filterDocument pred) $ conts)
| otherwise = Nothing
squashDocument :: Monoid a => Document a -> Document a
squashDocument term@(Terminal _) = term
squashDocument doc@(Document ident _) = Document ident [Terminal $ getContent doc]
getContent :: Monoid a => Document a -> a
getContent (Terminal a) = a
getContent (Document _ conts) = mconcat (fmap getContent conts)
squashDocumentOn :: forall a. Monoid a => (Document a -> Bool) -> Document a -> Document a
squashDocumentOn pred doc@(Document ident conts)
| pred doc = squashDocument doc
| otherwise = Document ident (squashDocumentOn pred <$> conts)
squashDocumentOn _ term@(Terminal _) = term
lookupDocument :: forall a. Text.Text
-> Document a
-> [Document a]
lookupDocument _ (Terminal _) = []
lookupDocument ident doc@(Document ident2 conts)
| ident2 == ident = [doc]
| otherwise = join $ lookupDocument ident <$> conts
lookupDocument' :: forall a. Text.Text
-> Document a
-> [Document a]
lookupDocument' _ (Terminal _) = []
lookupDocument' ident (Document _ conts) = catMaybes $ go ident <$> conts
where
go _ (Terminal _) = Nothing
go ident doc@(Document ident2 _) | ident == ident2 = Just doc
| otherwise = Nothing