Copyright	(C) 2014 Jan Stolarek
License	BSD-style (see LICENSE)
Maintainer	Jan Stolarek (jan.stolarek@p.lodz.pl)
Stability	experimental
Portability	non-portable
Safe Haskell	None
Language	Haskell2010

Data.Promotion.Prelude.Maybe

Contents

Promoted functions from Data.Maybe
Defunctionalization symbols

Description

Defines promoted functions and datatypes relating to Maybe, including a promoted version of all the definitions in Data.Maybe.

Because many of these definitions are produced by Template Haskell, it is not possible to create proper Haddock documentation. Please look up the corresponding operation in Data.Maybe. Also, please excuse the apparent repeated variable names. This is due to an interaction between Template Haskell and Haddock.

Synopsis

Promoted functions from `Data.Maybe`

maybe_ :: forall b a. b -> (a -> b) -> Maybe a -> b Source

type family Maybe_ a a a :: b Source

Equations

Maybe_ n z Nothing = n
Maybe_ z f (Just x) = Apply f x

The preceding two definitions is derived from the function maybe in Data.Maybe. The extra underscore is to avoid name clashes with the type Maybe.

type family IsJust a :: Bool Source

Equations

IsJust Nothing = FalseSym0
IsJust (Just z) = TrueSym0

type family IsNothing a :: Bool Source

Equations

IsNothing Nothing = TrueSym0
IsNothing (Just z) = FalseSym0

type family FromJust a :: a Source

Equations

FromJust Nothing = Apply ErrorSym0 "Maybe.fromJust: Nothing"
FromJust (Just x) = x

type family FromMaybe a a :: a Source

Equations

FromMaybe d x = Case_1627755653 d x (Let1627755645Scrutinee_1627755568Sym2 d x)

type family MaybeToList a :: [a] Source

Equations

MaybeToList Nothing = `[]`
MaybeToList (Just x) = Apply (Apply (:$) x) `[]`

type family ListToMaybe a :: Maybe a Source

Equations

ListToMaybe `[]` = NothingSym0
ListToMaybe ((:) a z) = Apply JustSym0 a

type family CatMaybes a :: [a] Source

Equations

CatMaybes `[]` = `[]`
CatMaybes ((:) (Just x) xs) = Apply (Apply (:$) x) (Apply CatMaybesSym0 xs)
CatMaybes ((:) Nothing xs) = Apply CatMaybesSym0 xs

type family MapMaybe a a :: [b] Source

Equations

MapMaybe z `[]` = `[]`
MapMaybe f ((:) x xs) = Case_1627755611 f x xs (Let1627755598Scrutinee_1627755570Sym3 f x xs)

Defunctionalization symbols

type NothingSym0 = Nothing Source

data JustSym0 l Source

Instances

SuppressUnusedWarnings (TyFun k (Maybe k) -> *) (JustSym0 k)
type Apply (Maybe k) k (JustSym0 k) l0 = JustSym1 k l0

type JustSym1 t = Just t Source

data Maybe_Sym0 l Source

Instances

SuppressUnusedWarnings (TyFun k (TyFun (TyFun k k -> ) (TyFun (Maybe k) k -> ) -> ) -> ) (Maybe_Sym0 k k)
type Apply (TyFun (TyFun k1 k -> ) (TyFun (Maybe k1) k -> ) -> *) k (Maybe_Sym0 k k1) l0 = Maybe_Sym1 k k1 l0

data Maybe_Sym1 l l Source

Instances

SuppressUnusedWarnings (k -> TyFun (TyFun k k -> ) (TyFun (Maybe k) k -> ) -> *) (Maybe_Sym1 k k)
type Apply (TyFun (Maybe k) k1 -> ) (TyFun k k1 -> ) (Maybe_Sym1 k1 k l1) l0 = Maybe_Sym2 k1 k l1 l0

data Maybe_Sym2 l l l Source

Instances

SuppressUnusedWarnings (k -> (TyFun k k -> ) -> TyFun (Maybe k) k -> ) (Maybe_Sym2 k k)
type Apply k (Maybe k1) (Maybe_Sym2 k k1 l1 l2) l0 = Maybe_Sym3 k k1 l1 l2 l0

type Maybe_Sym3 t t t = Maybe_ t t t Source

data IsJustSym0 l Source

Instances

SuppressUnusedWarnings (TyFun (Maybe k) Bool -> *) (IsJustSym0 k)
type Apply Bool (Maybe k) (IsJustSym0 k) l0 = IsJustSym1 k l0

type IsJustSym1 t = IsJust t Source

data IsNothingSym0 l Source

Instances

SuppressUnusedWarnings (TyFun (Maybe k) Bool -> *) (IsNothingSym0 k)
type Apply Bool (Maybe k) (IsNothingSym0 k) l0 = IsNothingSym1 k l0

type IsNothingSym1 t = IsNothing t Source

data FromJustSym0 l Source

Instances

SuppressUnusedWarnings (TyFun (Maybe k) k -> *) (FromJustSym0 k)
type Apply k (Maybe k) (FromJustSym0 k) l0 = FromJustSym1 k l0

type FromJustSym1 t = FromJust t Source

data FromMaybeSym0 l Source

Instances

SuppressUnusedWarnings (TyFun k (TyFun (Maybe k) k -> ) -> ) (FromMaybeSym0 k)
type Apply (TyFun (Maybe k) k -> *) k (FromMaybeSym0 k) l0 = FromMaybeSym1 k l0

data FromMaybeSym1 l l Source

Instances

SuppressUnusedWarnings (k -> TyFun (Maybe k) k -> *) (FromMaybeSym1 k)
type Apply k (Maybe k) (FromMaybeSym1 k l1) l0 = FromMaybeSym2 k l1 l0

type FromMaybeSym2 t t = FromMaybe t t Source

data MaybeToListSym0 l Source

Instances

SuppressUnusedWarnings (TyFun (Maybe k) [k] -> *) (MaybeToListSym0 k)
type Apply [k] (Maybe k) (MaybeToListSym0 k) l0 = MaybeToListSym1 k l0

type MaybeToListSym1 t = MaybeToList t Source

data ListToMaybeSym0 l Source

Instances

SuppressUnusedWarnings (TyFun [k] (Maybe k) -> *) (ListToMaybeSym0 k)
type Apply (Maybe k) [k] (ListToMaybeSym0 k) l0 = ListToMaybeSym1 k l0

type ListToMaybeSym1 t = ListToMaybe t Source

data CatMaybesSym0 l Source

Instances

SuppressUnusedWarnings (TyFun [Maybe k] [k] -> *) (CatMaybesSym0 k)
type Apply [k] [Maybe k] (CatMaybesSym0 k) l0 = CatMaybesSym1 k l0

type CatMaybesSym1 t = CatMaybes t Source

data MapMaybeSym0 l Source

Instances

SuppressUnusedWarnings (TyFun (TyFun k (Maybe k) -> ) (TyFun [k] [k] -> ) -> *) (MapMaybeSym0 k k)
type Apply (TyFun [k] [k1] -> ) (TyFun k (Maybe k1) -> ) (MapMaybeSym0 k k1) l0 = MapMaybeSym1 k k1 l0

data MapMaybeSym1 l l Source

Instances

SuppressUnusedWarnings ((TyFun k (Maybe k) -> ) -> TyFun [k] [k] -> ) (MapMaybeSym1 k k)
type Apply [k1] [k] (MapMaybeSym1 k k1 l1) l0 = MapMaybeSym2 k k1 l1 l0

type MapMaybeSym2 t t = MapMaybe t t Source

Promoted functions from Data.Maybe

Defunctionalization symbols

Promoted functions from `Data.Maybe`