applicative-fail 0.0.1 → 0.0.2

raw patch · 3 files changed

+75/−8 lines, 3 filesdep +bifunctorsPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

Dependencies added: bifunctors

API changes (from Hackage documentation)

Files

• README.md +62/−0
• applicative-fail.cabal +7/−2
• src/Control/Applicative/Fail.hs +6/−6

@@ -0,0 +1,62 @@+# What is it for?++Assume you have some type++```haskell+data Animal =+    Animal+    { species :: String+    , weight  :: Double+    , age     :: NominalDiffTime+    }+```++And you would like to produce this value from some data (e.g. query+parameters). There can be some warnigns or value can not be produced+at all. It would be great to have some simple tool to notify about+warnings and/or fail computation.++Like that:++```haskell+spc = "Parastratiosphecomyia stratiosphecomyioides"+w = 100+a = 27234++animal = Animal+         <$> (if length spc > 20+              then fwarn "Name is too long" spc+              else if spc == ""+                   then ffail "Name can not be empty"+                   else fsucc spc)+         <*> (if w < 0+              then ffail "Weight can not be negative"+              else fsucc w)+         <*> (if a < 0+              then ffail "Age can not be negative"+              else fsucc a)+```++Now you can inspect the value we have got++```haskell+λ> animal+Fail ["Name is too long"] (Just (Animal {species = "Parastratiosphecomyia stratiosphecomyioides", weight = 100.0, age = 27234}))+λ> getSucc animal+Just (Animal {species = "Parastratiosphecomyia stratiosphecomyioides", weight = 100.0, age = 27234})+λ> getFail animal+Just ["Name is too long"]+```++Here is another simple examples:++```haskell+λ> (,) <$> ffail "oups" <*> ffail "duh"+Fail ["oups","duh"] Nothing+λ> (,) <$> fwarn "oups" "hello" <*> fwarn "duh" "world"+Fail ["oups","duh"] (Just ("hello","world"))+λ> (,) <$> fsucc "hello" <*> fwarn "duh" "world"+Fail ["duh"] (Just ("hello","world"))+λ> (,) <$> fsucc "hello" <*> fsucc "world"+Success ("hello","world")+```

@@ -1,9 +1,9 @@ name:                applicative-fail-version:             0.0.1+version:             0.0.2 synopsis:            Applicative functor which collects all your fails  description: Applicative functor to perform parse-like actions and-             collect wanrings/failures while+             collect wanrings/failures  license:             BSD3 license-file:        LICENSE@@ -15,6 +15,8 @@  cabal-version:       >=1.10 +extra-source-files:  README.md+ homepage: https://bitbucket.org/s9gf4ult/applicative-fail source-repository head   type: git@@ -31,5 +33,8 @@                      , DeriveTraversable    build-depends:       base >=4.6 && <4.8+                     , bifunctors    exposed-modules:     Control.Applicative.Fail++  ghc-options: -Wall

@@ -7,13 +7,13 @@        , getSucc          -- * Combinators        , failEither-       , mapFail        , joinFail        , bindFail        , composeFail        ) where  import Control.Applicative+import Data.Bifunctor import Data.Foldable import Data.Monoid import Data.Traversable@@ -58,6 +58,10 @@              , Foldable, Traversable              , Typeable, Generic ) +instance Bifunctor Fail where+    bimap fe fa (Fail e a) = Fail (fe e) (fa <$> a)+    bimap _ fa (Success a) = Success (fa a)+ instance (Monoid e) => Applicative (Fail e) where     pure a = Success a     (Success f) <*> a = fmap f a@@ -90,11 +94,7 @@  getSucc :: Fail e a -> Maybe a getSucc (Success a) = Just a-getSucc _ = Nothing--mapFail :: (e -> e') -> Fail e a -> Fail e' a-mapFail _ (Success a) = Success a-mapFail f (Fail e a)  = Fail (f e) a+getSucc (Fail _ a) = a  -- | Join two fails like monad does joinFail :: (Monoid e)