diff options
Diffstat (limited to 'src/GF/Data')
| -rw-r--r-- | src/GF/Data/Operations.hs | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/GF/Data/Operations.hs b/src/GF/Data/Operations.hs index 7110a7ac0..6dd78e1bc 100644 --- a/src/GF/Data/Operations.hs +++ b/src/GF/Data/Operations.hs @@ -26,6 +26,10 @@ instance Monad Err where Ok a >>= f = f a Bad s >>= f = Bad s +instance Functor Err where -- added 2/10/2003 by PEB + fmap f (Ok a) = Ok (f a) + fmap f (Bad s) = Bad s + -- analogue of maybe err :: (String -> b) -> (a -> b) -> Err a -> b err d f e = case e of |