-- Hoogle documentation, generated by Haddock -- See Hoogle, http://www.haskell.org/hoogle/ -- | Validity typeclass -- -- For more info, see the readme. -- -- Note: There are companion instance packages for this library: -- -- @package validity @version 0.12.0.0 -- | Validity is used to specify additional invariants upon values -- that are not enforced by the type system. -- -- Let's take an example. Suppose we were to implement a type -- Prime that represents prime integers. -- -- If you were to completely enforce the invariant that the represented -- number is a prime, then we could use Natural and only store the -- index of the given prime in the infinite sequence of prime numbers. -- This is very safe but also very expensive if we ever want to use the -- number, because we would have to calculcate all the prime numbers -- until that index. -- -- Instead we choose to implement Prime by a newtype Prime = -- Prime Int. Now we have to maintain the invariant that the -- Int that we use to represent the prime is in fact positive -- and a prime. -- -- The Validity typeclass allows us to specify this invariant -- (and enables testing via the genvalidity libraries: -- https://hackage.haskell.org/package/genvalidity ): -- -- 
--   instance Validity Prime where
--       validate (Prime n) = check (isPrime n) "The 'Int' is prime."
--
-- -- If certain typeclass invariants exist, you can make these explicit in -- the validity instance as well. For example, 'Fixed a' is only valid if -- a has an HasResolution instance, so the correct -- validity instance is HasResolution a => Validity (Fixed -- a). module Data.Validity -- | A class of types that have additional invariants defined upon them class Validity a validate :: Validity a => a -> Validation validate :: (Validity a, Generic a, GValidity (Rep a)) => a -> Validation -- | Declare any value to be valid in validation -- -- 
--   trivialValidation a = seq a mempty
--
trivialValidation :: a -> Validation genericValidate :: (Generic a, GValidity (Rep a)) => a -> Validation -- | Check that a given invariant holds. -- -- The given string should describe the invariant, not the violation. -- -- Example: -- -- 
--   check (x < 5) "x is strictly smaller than 5"
--
-- -- instead of -- -- 
--   check (x < 5) "x is greater than 5"
--
check :: Bool -> String -> Validation -- | check, but with the arguments flipped declare :: String -> Bool -> Validation -- | Declare a sub-part as a necessary part for validation, and annotate it -- with a name. -- -- Example: -- -- 
--   validate (a, b) =
--       mconcat
--           [ annotate a "The first element of the tuple"
--           , annotate b "The second element of the tuple"
--           ]
--
annotate :: Validity a => a -> String -> Validation -- | annotate, but with the arguments flipped. delve :: Validity a => String -> a -> Validation -- | Decorate a validation with a location decorate :: String -> Validation -> Validation -- | Decorate a piecewise validation of a list with their location in the -- list decorateList :: [a] -> (a -> Validation) -> Validation -- | Construct a trivially invalid Validation -- -- Example: -- -- 
--   data Wrong
--       = Wrong
--       | Fine
--       deriving (Show, Eq)
--   
--   instance Validity Wrong where
--       validate w =
--           case w of
--               Wrong -> invalid "Wrong"
--               Fine -> valid
--
invalid :: String -> Validation valid :: Validation validateCharNotUtf16SurrogateCodePoint :: Char -> Validation isUtf16SurrogateCodePoint :: Char -> Bool validateCharNotLineSeparator :: Char -> Validation isLineSeparator :: Char -> Bool validateStringSingleLine :: String -> Validation isSingleLine :: String -> Bool validateNotNaN :: RealFloat a => a -> Validation validateNotInfinite :: RealFloat a => a -> Validation validateRatioNotNaN :: Integral a => Ratio a -> Validation validateRatioNotInfinite :: Integral a => Ratio a -> Validation validateRatioNormalised :: Integral a => Ratio a -> Validation -- | Check whether a value is valid. isValid :: Validity a => a -> Bool -- | Check whether a value is not valid. -- -- 
--   isInvalid = not . isValid
--
isInvalid :: Validity a => a -> Bool -- | Construct a valid element from an unchecked element constructValid :: Validity a => a -> Maybe a -- | Construct a valid element from an unchecked element, throwing -- error on invalid elements. constructValidUnsafe :: (Show a, Validity a) => a -> a -- | The result of validating a value. -- -- mempty means the value was valid. -- -- This type intentionally doesn't have a Validity instance to -- make sure you can never accidentally use annotate or -- delve twice. newtype Validation Validation :: [ValidationChain] -> Validation [unValidation] :: Validation -> [ValidationChain] data ValidationChain Violated :: String -> ValidationChain Location :: String -> ValidationChain -> ValidationChain -- | validate a given value. -- -- This function returns either all the reasons why the given value is -- invalid, in the form of a list of ValidationChains, or it -- returns Right with the input value, as evidence that it is -- valid. -- -- Note: You may want to use prettyValidation instead, if you want -- to display these ValidationChains to a user. checkValidity :: Validity a => a -> Either [ValidationChain] a -- | Check if a Validation concerns a valid value. validationIsValid :: Validation -> Bool -- | Validate a given value -- -- This function will return a nice error if the value is invalid. It -- will return the original value in Right if it was valid, as -- evidence that it has been validated. prettyValidate :: Validity a => a -> Either String a -- | Render a Validation in a somewhat pretty way. -- -- This function will return Nothing if the Validation -- concerned a valid value. prettyValidation :: Validation -> Maybe String -- | The class of monoids (types with an associative binary operation that -- has an identity). Instances should satisfy the following: -- -- -- -- The method names refer to the monoid of lists under concatenation, but -- there are many other instances. -- -- Some types can be viewed as a monoid in more than one way, e.g. both -- addition and multiplication on numbers. In such cases we often define -- newtypes and make those instances of Monoid, e.g. -- Sum and Product. -- -- NOTE: Semigroup is a superclass of Monoid since -- base-4.11.0.0. class Semigroup a => Monoid a -- | Identity of mappend -- -- 
--   >>> "Hello world" <> mempty
--   "Hello world"
--
mempty :: Monoid a => a -- | An associative operation -- -- NOTE: This method is redundant and has the default -- implementation mappend = (<>) since -- base-4.11.0.0. Should it be implemented manually, since -- mappend is a synonym for (<>), it is expected that -- the two functions are defined the same way. In a future GHC release -- mappend will be removed from Monoid. mappend :: Monoid a => a -> a -> a -- | Fold a list using the monoid. -- -- For most types, the default definition for mconcat will be -- used, but the function is included in the class definition so that an -- optimized version can be provided for specific types. -- -- 
--   >>> mconcat ["Hello", " ", "Haskell", "!"]
--   "Hello Haskell!"
--
mconcat :: Monoid a => [a] -> a -- | The class of semigroups (types with an associative binary operation). -- -- Instances should satisfy the following: -- -- class Semigroup a -- | An associative operation. -- -- 
--   >>> [1,2,3] <> [4,5,6]
--   [1,2,3,4,5,6]
--
(<>) :: Semigroup a => a -> a -> a infixr 6 <> instance GHC.Generics.Generic Data.Validity.ValidationChain instance GHC.Classes.Eq Data.Validity.ValidationChain instance GHC.Show.Show Data.Validity.ValidationChain instance GHC.Generics.Generic Data.Validity.Validation instance GHC.Classes.Eq Data.Validity.Validation instance GHC.Show.Show Data.Validity.Validation instance Data.Validity.Validity Data.Validity.ValidationChain instance (Data.Validity.Validity a, Data.Validity.Validity b) => Data.Validity.Validity (a, b) instance (Data.Validity.Validity a, Data.Validity.Validity b) => Data.Validity.Validity (Data.Either.Either a b) instance (Data.Validity.Validity a, Data.Validity.Validity b, Data.Validity.Validity c) => Data.Validity.Validity (a, b, c) instance (Data.Validity.Validity a, Data.Validity.Validity b, Data.Validity.Validity c, Data.Validity.Validity d) => Data.Validity.Validity (a, b, c, d) instance (Data.Validity.Validity a, Data.Validity.Validity b, Data.Validity.Validity c, Data.Validity.Validity d, Data.Validity.Validity e) => Data.Validity.Validity (a, b, c, d, e) instance (Data.Validity.Validity a, Data.Validity.Validity b, Data.Validity.Validity c, Data.Validity.Validity d, Data.Validity.Validity e, Data.Validity.Validity f) => Data.Validity.Validity (a, b, c, d, e, f) instance Data.Validity.Validity a => Data.Validity.Validity [a] instance Data.Validity.Validity a => Data.Validity.Validity (GHC.Base.NonEmpty a) instance Data.Validity.Validity a => Data.Validity.Validity (GHC.Maybe.Maybe a) instance Data.Validity.Validity () instance Data.Validity.Validity GHC.Types.Bool instance Data.Validity.Validity GHC.Types.Ordering instance Data.Validity.Validity GHC.Types.Char instance Data.Validity.Validity GHC.Types.Int instance Data.Validity.Validity GHC.Int.Int8 instance Data.Validity.Validity GHC.Int.Int16 instance Data.Validity.Validity GHC.Int.Int32 instance Data.Validity.Validity GHC.Int.Int64 instance Data.Validity.Validity GHC.Types.Word instance Data.Validity.Validity GHC.Word.Word8 instance Data.Validity.Validity GHC.Word.Word16 instance Data.Validity.Validity GHC.Word.Word32 instance Data.Validity.Validity GHC.Word.Word64 instance Data.Validity.Validity GHC.Types.Float instance Data.Validity.Validity GHC.Types.Double instance Data.Validity.Validity GHC.Integer.Type.Integer instance Data.Validity.Validity GHC.Natural.Natural instance (Data.Validity.Validity a, GHC.Classes.Ord a, GHC.Num.Num a, GHC.Real.Integral a) => Data.Validity.Validity (GHC.Real.Ratio a) instance Data.Fixed.HasResolution a => Data.Validity.Validity (Data.Fixed.Fixed a) instance Data.Validity.Validity a => Data.Validity.GValidity (GHC.Generics.K1 GHC.Generics.R a) instance Data.Validity.GValidity GHC.Generics.U1 instance Data.Validity.GValidity GHC.Generics.V1 instance (Data.Validity.GValidity a, Data.Validity.GValidity b) => Data.Validity.GValidity (a GHC.Generics.:*: b) instance (Data.Validity.GValidity a, Data.Validity.GValidity b) => Data.Validity.GValidity (a GHC.Generics.:+: b) instance (Data.Validity.GValidity a, GHC.Generics.Datatype c) => Data.Validity.GValidity (GHC.Generics.M1 GHC.Generics.D c a) instance (Data.Validity.GValidity a, GHC.Generics.Constructor c) => Data.Validity.GValidity (GHC.Generics.M1 GHC.Generics.C c a) instance (Data.Validity.GValidity a, GHC.Generics.Selector c) => Data.Validity.GValidity (GHC.Generics.M1 GHC.Generics.S c a) instance GHC.Base.Semigroup Data.Validity.Validation instance GHC.Base.Monoid Data.Validity.Validation