Safe Haskell	Safe-Inferred
Language	GHC2021

Strongweak.Weaken

Contents

Weaken class
Strength switch helper

Synopsis

class Weaken a where
- type Weak a :: Type
- weaken :: a -> Weak a
liftWeakF :: Weaken a => (Weak a -> b) -> a -> b
data Strength
- = Strong
- | Weak
type family SW (s :: Strength) a :: Type where ...
type family SWDepth (n :: Natural) a :: Type where ...

`Weaken` class

class Weaken a where Source #

Weaken some a, relaxing certain invariants.

See Strongweak for class design notes and laws.

Associated Types

type Weak a :: Type Source #

The weakened type for some type.

Methods

weaken :: a -> Weak a Source #

Weaken some a to its associated weak type Weaken a.

Instances

Instances details

Weaken Int16 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Int16 Source # Methods weaken :: Int16 -> Weak Int16 Source #
Weaken Int32 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Int32 Source # Methods weaken :: Int32 -> Weak Int32 Source #
Weaken Int64 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Int64 Source # Methods weaken :: Int64 -> Weak Int64 Source #
Weaken Int8 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Int8 Source # Methods weaken :: Int8 -> Weak Int8 Source #
Weaken Word16 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Word16 Source # Methods weaken :: Word16 -> Weak Word16 Source #
Weaken Word32 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Word32 Source # Methods weaken :: Word32 -> Weak Word32 Source #
Weaken Word64 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Word64 Source # Methods weaken :: Word64 -> Weak Word64 Source #
Weaken Word8 Source #
Instance details Defined in Strongweak.Weaken Associated Types type Weak Word8 Source # Methods weaken :: Word8 -> Weak Word8 Source #
Weaken (Identity a) Source #	Strip wrapper.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Identity a) Source # Methods weaken :: Identity a -> Weak (Identity a) Source #
Weaken (NonEmpty a) Source #	Weaken non-empty lists into plain lists.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (NonEmpty a) Source # Methods weaken :: NonEmpty a -> Weak (NonEmpty a) Source #
Weaken a => Weaken [a] Source #	Decomposer. Weaken every element in a list.
Instance details Defined in Strongweak.Weaken Associated Types type Weak [a] Source # Methods weaken :: [a] -> Weak [a] Source #
(Weaken a, Weaken b) => Weaken (Either a b) Source #	Decomposer. Weaken either side of an `Either`.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Either a b) Source # Methods weaken :: Either a b -> Weak (Either a b) Source #
(Generic s, Generic w, GWeaken (Rep s) (Rep w)) => Weaken (GenericallySW s w) Source #
Instance details Defined in Strongweak.Generic.Via Associated Types type Weak (GenericallySW s w) Source # Methods weaken :: GenericallySW s w -> Weak (GenericallySW s w) Source #
(Weaken a, Weaken b) => Weaken (a, b) Source #	Decomposer. Weaken both elements of a tuple.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (a, b) Source # Methods weaken :: (a, b) -> Weak (a, b) Source #
Weaken (Const a b) Source #	Strip wrapper.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Const a b) Source # Methods weaken :: Const a b -> Weak (Const a b) Source #
Weaken (Refined p a) Source #	Strip refined type refinement.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Refined p a) Source # Methods weaken :: Refined p a -> Weak (Refined p a) Source #
Vector v a => Weaken (Vector v n a) Source #	Weaken sized vectors into plain lists.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Vector v n a) Source # Methods weaken :: Vector v n a -> Weak (Vector v n a) Source #
Weaken (Refined1 p f a) Source #	Strip refined functor type refinement.
Instance details Defined in Strongweak.Weaken Associated Types type Weak (Refined1 p f a) Source # Methods weaken :: Refined1 p f a -> Weak (Refined1 p f a) Source #

liftWeakF :: Weaken a => (Weak a -> b) -> a -> b Source #

Lift a function on a weak type to the associated strong type by weakening first.

Strength switch helper

data Strength Source #

Strength enumeration: is it strong, or weak?

Primarily interesting at the type level (using DataKinds).

Constructors

Strong
Weak

type family SW (s :: Strength) a :: Type where ... Source #

Get either the strong or weak representation of a type, depending on the type-level "switch" provided.

This is intended to be used in data types that take a Strength type. Define your type using strong fields wrapped in SW s. You then get the weak representation for free, using the same definition.

data A (s :: Strength) = A
  { a1 :: SW s Word8
  , a2 :: String }

Equations

SW 'Strong a = a
SW 'Weak a = Weak a

type family SWDepth (n :: Natural) a :: Type where ... Source #

Track multiple levels of weakening. Silly thought I had, don't think it's useful.

Equations

SWDepth 0 a = a
SWDepth n a = Weak (SWDepth (n - 1) a)

Weaken class

Instances

Strength switch helper

`Weaken` class