safe 0.3.1 → 0.3.2

raw patch · 2 files changed

+69/−1 lines, 2 files

Files

• Safe/Foldable.hs +67/−0
• safe.cabal +2/−1

@@ -0,0 +1,67 @@+{- |+Equivalent versions to the "Safe" module, but generalised to work+over any 'Foldable' type.+-}+module Safe.Foldable where++import Data.Foldable+import Data.Monoid+import Data.Maybe+import Prelude hiding (foldl, foldr)++mfl :: (a -> a -> a) -> Maybe a -> a -> Maybe a+mfl _ Nothing x = Just x+mfl fun (Just y) x = Just (fun y x)++-- |+-- > Same as Data.Foldable.foldl1+foldl1Note :: Foldable t => String -> (a -> a -> a) -> t a -> a+foldl1Note msg fun fld = fromMaybe (error $ "Safe.Foldable.foldl1Note: empty list, " ++ msg) (foldl (mfl fun) Nothing fld)++foldl1Def :: Foldable t => a -> (a -> a -> a) -> t a -> a+foldl1Def def fun fld = fromMaybe def (foldl (mfl fun) Nothing fld)++foldl1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a+foldl1May fun = foldl (mfl fun) Nothing++-- | Default value is the mempty from a monoid+foldl1Safe :: (Monoid m, Foldable t) => (m -> m -> m) -> t m -> m+foldl1Safe fun = foldl fun mempty+++mfr :: (a -> a -> a) -> a -> Maybe a -> Maybe a+mfr _ x Nothing = Just x+mfr fun x (Just y) = Just (fun x y)++-- |+-- > Same as Data.Foldable.foldr1+foldr1Note :: Foldable t => String -> (a -> a -> a) -> t a -> a+foldr1Note msg fun fld = fromMaybe (error $ "Safe.Foldable.foldr1Note: empty list, " ++ msg) (foldr (mfr fun) Nothing fld)++foldr1Def :: Foldable t => a -> (a -> a -> a) -> t a -> a+foldr1Def def fun fld = fromMaybe def (foldr (mfr fun) Nothing fld)++foldr1May :: Foldable t => (a -> a -> a) -> t a -> Maybe a+foldr1May fun = foldr (mfr fun) Nothing++-- | Default value is the mempty from a monoid+foldr1Safe :: (Monoid m, Foldable t) => (m -> m -> m) -> t m -> m+foldr1Safe fun = foldr fun mempty++-- |+-- > Same as Data.Foldable.find++findJust :: Foldable t => (a -> Bool) -> t a -> a+findJust op fld = fromMaybe (error "Safe.Foldable.findJust, item not found") (find op fld)++findJustDef :: Foldable t => a -> (a -> Bool) -> t a -> a+findJustDef def op fld = fromMaybe def (find op fld)++findJustNote :: Foldable t => String -> (a -> Bool) -> t a -> a+findJustNote msg op fld = fromMaybe (error $ "Safe.Foldable.findJustNote: element not found, " ++ msg) (find op fld)++-- | Default value is the mempty from a monoid+findJustSafe :: (Monoid m, Foldable t) => (m -> Bool) -> t m -> m+findJustSafe op fld = fromMaybe mempty (find op fld)++

@@ -1,7 +1,7 @@ cabal-version:  >= 1.6 build-type:     Simple name:           safe-version:        0.3.1+version:        0.3.2 license:        BSD3 license-file:   LICENSE category:       Unclassified@@ -30,3 +30,4 @@      exposed-modules:         Safe+        Safe.Foldable