Copyright	(c) Galois Inc 2014
Maintainer	Joe Hendrix <jhendrix@galois.com>
Stability	provisional
Safe Haskell	Unsafe
Language	Haskell2010

Data.Parameterized.Nonce.Unsafe

Description

Deprecated: Migrate to use Data.Parameterized.Nonce instead, this module will be removed soon.

This module provides a simple generator of new indexes in the ST monad. It is predictable and not intended for cryptographic purposes.

NOTE: the TestEquality and OrdF instances for the Nonce type simply compare the generated nonce values and then assert to the compiler (via unsafeCoerce) that the types ascribed to the nonces are equal if their values are equal. This is only OK because of the discipline by which nonces should be used: they should only be generated from a NonceGenerator (i.e., should not be built directly), and nonces from different generators must never be compared! Arranging to compare Nonces from different origins would allow users to build unsafeCoerce via the testEquality function.

This module is deprecated, and should not be used in new code. Clients of this module should migrate to use Data.Parameterized.Nonce.

Synopsis

data NonceGenerator s
newNonceGenerator :: ST s (NonceGenerator s)
freshNonce :: NonceGenerator s -> ST s (Nonce tp)
atLimit :: NonceGenerator s -> ST s Bool
data Nonce (tp :: k)
indexValue :: Nonce tp -> Word64

Documentation

data NonceGenerator s Source #

A simple type that for getting fresh indices in the ST monad. The type parameter s is used for the ST monad parameter.

newNonceGenerator :: ST s (NonceGenerator s) Source #

Create a new counter.

freshNonce :: NonceGenerator s -> ST s (Nonce tp) Source #

Get a fresh index and increment the counter.

atLimit :: NonceGenerator s -> ST s Bool Source #

Return true if counter has reached the limit, and can't be incremented without risk of error.

data Nonce (tp :: k) Source #

An index generated by the counter.

Instances

Instances details

TestEquality (Nonce :: k -> Type) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods testEquality :: forall (a :: k0) (b :: k0). Nonce a -> Nonce b -> Maybe (a :~: b) #
HashableF (Nonce :: k -> Type) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods hashWithSaltF :: forall (tp :: k0). Int -> Nonce tp -> Int Source # hashF :: forall (tp :: k0). Nonce tp -> Int Source #
OrdF (Nonce :: k -> Type) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods compareF :: forall (x :: k0) (y :: k0). Nonce x -> Nonce y -> OrderingF x y Source # leqF :: forall (x :: k0) (y :: k0). Nonce x -> Nonce y -> Bool Source # ltF :: forall (x :: k0) (y :: k0). Nonce x -> Nonce y -> Bool Source # geqF :: forall (x :: k0) (y :: k0). Nonce x -> Nonce y -> Bool Source # gtF :: forall (x :: k0) (y :: k0). Nonce x -> Nonce y -> Bool Source #
ShowF (Nonce :: k -> Type) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods withShow :: forall p q (tp :: k0) a. p Nonce -> q tp -> (Show (Nonce tp) => a) -> a Source # showF :: forall (tp :: k0). Nonce tp -> String Source # showsPrecF :: forall (tp :: k0). Int -> Nonce tp -> String -> String Source #
Show (Nonce tp) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods showsPrec :: Int -> Nonce tp -> ShowS # show :: Nonce tp -> String # showList :: [Nonce tp] -> ShowS #
Eq (Nonce tp) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods (==) :: Nonce tp -> Nonce tp -> Bool # (/=) :: Nonce tp -> Nonce tp -> Bool #
Ord (Nonce tp) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods compare :: Nonce tp -> Nonce tp -> Ordering # (<) :: Nonce tp -> Nonce tp -> Bool # (<=) :: Nonce tp -> Nonce tp -> Bool # (>) :: Nonce tp -> Nonce tp -> Bool # (>=) :: Nonce tp -> Nonce tp -> Bool # max :: Nonce tp -> Nonce tp -> Nonce tp # min :: Nonce tp -> Nonce tp -> Nonce tp #
Hashable (Nonce tp) Source #
Instance details Defined in Data.Parameterized.Nonce.Unsafe Methods hashWithSalt :: Int -> Nonce tp -> Int # hash :: Nonce tp -> Int #

indexValue :: Nonce tp -> Word64 Source #