Combinators.hs

{-# LANGUAGE NoImplicitPrelude #-}

-- | More readable combinators for writing parsers.
module Data.Attoparsec.Combinators
  ( alternating
  , appending
  , concating
  , pured
  ) where

import           Stack.Prelude

-- | Concatenate two parsers.
appending ::
     (Applicative f, Semigroup a)
  => f a
  -> f a
  -> f a
appending a b = (<>) <$> a <*> b

-- | Alternative parsers.
alternating :: Alternative f => f a -> f a -> f a
alternating a b = a <|> b

-- | Pure something.
pured :: (Applicative g, Applicative f) => g a -> g (f a)
pured = fmap pure

-- | Concating the result of an action.
concating :: (Monoid m, Applicative f) => f [m] -> f m
concating = fmap mconcat