Safe Haskell	Trustworthy
Language	Haskell2010

Data.Type.Equality.Hetero

Description

This module shims kind heterogeneous propositional equality.

Note: some instances: Read, Enum, Bounded and Data would be available only since GHC-8.0 as we need ~~ constraint. Also GH-7.10.3 is nitpicky data constructor ‘HRefl’ cannot be GADT-like in its *kind* arguments, thus this module is available only with GHC >= 8.0

Synopsis

data (a :: k1) :~~: (b :: k2) where
- HRefl :: forall {k1} (a :: k1). a :~~: a

Documentation

data (a :: k1) :~~: (b :: k2) where infix 4 Source #

Kind heterogeneous propositional equality. Like :~:, a :~~: b is inhabited by a terminating value if and only if a is the same type as b.

Since: base-4.10.0.0

Constructors

HRefl :: forall {k1} (a :: k1). a :~~: a

Instances

Instances details

TestEquality ((:~~:) a :: k -> Type)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods testEquality :: forall (a0 :: k0) (b :: k0). (a :~~: a0) -> (a :~~: b) -> Maybe (a0 :~: b) Source #
a ~~ b => Bounded (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods minBound :: a :~~: b Source # maxBound :: a :~~: b Source #
a ~~ b => Enum (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods succ :: (a :~~: b) -> a :~~: b Source # pred :: (a :~~: b) -> a :~~: b Source # toEnum :: Int -> a :~~: b Source # fromEnum :: (a :~~: b) -> Int Source # enumFrom :: (a :~~: b) -> [a :~~: b] Source # enumFromThen :: (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source # enumFromTo :: (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source # enumFromThenTo :: (a :~~: b) -> (a :~~: b) -> (a :~~: b) -> [a :~~: b] Source #
a ~~ b => Read (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods readsPrec :: Int -> ReadS (a :~~: b) Source # readList :: ReadS [a :~~: b] Source # readPrec :: ReadPrec (a :~~: b) Source # readListPrec :: ReadPrec [a :~~: b] Source #
Show (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods showsPrec :: Int -> (a :~~: b) -> ShowS Source # show :: (a :~~: b) -> String Source # showList :: [a :~~: b] -> ShowS Source #
Eq (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods (==) :: (a :~~: b) -> (a :~~: b) -> Bool Source # (/=) :: (a :~~: b) -> (a :~~: b) -> Bool Source #
Ord (a :~~: b)	Since: base-4.10.0.0
Instance details Defined in Data.Type.Equality Methods compare :: (a :~~: b) -> (a :~~: b) -> Ordering Source # (<) :: (a :~~: b) -> (a :~~: b) -> Bool Source # (<=) :: (a :~~: b) -> (a :~~: b) -> Bool Source # (>) :: (a :~~: b) -> (a :~~: b) -> Bool Source # (>=) :: (a :~~: b) -> (a :~~: b) -> Bool Source # max :: (a :~~: b) -> (a :~~: b) -> a :~~: b Source # min :: (a :~~: b) -> (a :~~: b) -> a :~~: b Source #