Commit f2bf8347 authored by Benno Fünfstück's avatar Benno Fünfstück
Browse files

Add Functor/Applicative instances for ParseResult

ParseResult is a Monad, so it should also be a Functor and an Applicative.
parent cd935e2e
......@@ -87,7 +87,8 @@ import Data.Char (isSpace, toLower, isAlphaNum, isDigit)
import Data.Maybe (fromMaybe)
import Data.Tree as Tree (Tree(..), flatten)
import qualified Data.Map as Map
import Control.Monad (foldM)
import Control.Monad (foldM)
import Control.Applicative (Applicative(..))
import System.FilePath (normalise)
import Data.List (sortBy)
......@@ -115,6 +116,14 @@ showPWarning fpath (UTFWarning line fname) =
data ParseResult a = ParseFailed PError | ParseOk [PWarning] a
deriving Show
instance Functor ParseResult where
fmap f (ParseFailed err) = ParseFailed err
fmap f (ParseOk ws x) = ParseOk ws $ f x
instance Applicative ParseResult where
pure = ParseOk []
f <*> a = join $ fmap (\f' -> fmap f' a)
instance Monad ParseResult where
return = ParseOk []
ParseFailed err >>= _ = ParseFailed err
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