Safe Haskell	Safe-Inferred
Language	Haskell2010

Strongweak.Generic.Strengthen

Description

Strengthening for generic data types.

The generic derivation is split into 3 classes, each dealing with a different layer of a generic Haskell data type: datatype (D), constructor (C) and selector (S). At each point, we gather up information about the type and push on. Strengthening occurs at selectors. If a strengthening fails, the gathered information is pushed into an error that wraps the original error.

Synopsis

strengthenGeneric :: (Generic w, Generic s, GStrengthenD (Rep w) (Rep s)) => w -> Validation (NonEmpty StrengthenError) s
class GStrengthenD w s where
- gstrengthenD :: w p -> Validation (NonEmpty StrengthenError) (s p)
class GStrengthenC w s where
- gstrengthenC :: String -> String -> w p -> Validation (NonEmpty StrengthenError) (s p)
class GStrengthenS w s where
- gstrengthenS :: String -> String -> String -> String -> Natural -> w p -> (Natural, Validation (NonEmpty StrengthenError) (s p))
selName'' :: forall s. Selector s => Maybe String
conName' :: forall c. Constructor c => String
datatypeName' :: forall d. Datatype d => String
selName' :: forall s. Selector s => String

Documentation

strengthenGeneric :: (Generic w, Generic s, GStrengthenD (Rep w) (Rep s)) => w -> Validation (NonEmpty StrengthenError) s Source #

class GStrengthenD w s where Source #

Methods

gstrengthenD :: w p -> Validation (NonEmpty StrengthenError) (s p) Source #

Instances

Instances details

(GStrengthenC w s, Datatype dw, Datatype ds) => GStrengthenD (D1 dw w :: k -> Type) (D1 ds s :: k -> Type) Source #
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenD :: forall (p :: k0). D1 dw w p -> Validation (NonEmpty StrengthenError) (D1 ds s p) Source #

class GStrengthenC w s where Source #

Methods

gstrengthenC :: String -> String -> w p -> Validation (NonEmpty StrengthenError) (s p) Source #

Instances

Instances details

GStrengthenC (V1 :: k -> Type) (V1 :: k -> Type) Source #	Nothing to do for empty datatypes.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenC :: forall (p :: k0). String -> String -> V1 p -> Validation (NonEmpty StrengthenError) (V1 p) Source #
(GStrengthenC lw ls, GStrengthenC rw rs) => GStrengthenC (lw :+: rw :: k -> Type) (ls :+: rs :: k -> Type) Source #	Strengthen sum types by strengthening left or right.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenC :: forall (p :: k0). String -> String -> (lw :+: rw) p -> Validation (NonEmpty StrengthenError) ((ls :+: rs) p) Source #
(GStrengthenS w s, Constructor cw, Constructor cs) => GStrengthenC (C1 cw w :: k -> Type) (C1 cs s :: k -> Type) Source #
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenC :: forall (p :: k0). String -> String -> C1 cw w p -> Validation (NonEmpty StrengthenError) (C1 cs s p) Source #

class GStrengthenS w s where Source #

Methods

gstrengthenS :: String -> String -> String -> String -> Natural -> w p -> (Natural, Validation (NonEmpty StrengthenError) (s p)) Source #

Instances

Instances details

GStrengthenS (U1 :: k -> Type) (U1 :: k -> Type) Source #	Nothing to do for empty constructors.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenS :: forall (p :: k0). String -> String -> String -> String -> Natural -> U1 p -> (Natural, Validation (NonEmpty StrengthenError) (U1 p)) Source #
(GStrengthenS lw ls, GStrengthenS rw rs) => GStrengthenS (lw :: rw :: k -> Type) (ls :: rs :: k -> Type) Source #	Strengthen product types by strengthening left and right. This is ordered (left then right), but only to pass the index along.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenS :: forall (p :: k0). String -> String -> String -> String -> Natural -> (lw :: rw) p -> (Natural, Validation (NonEmpty StrengthenError) ((ls :: rs) p)) Source #
(Strengthen w s, Selector mw, Selector ms) => GStrengthenS (S1 mw (Rec0 w) :: k -> Type) (S1 ms (Rec0 s) :: k -> Type) Source #	Strengthen a field using the existing `Strengthen` instance. On strengthen failure, the errors are annotated with all the datatype information we've hoarded. The upshot is that if you strengthen a type with lots of types inside it, all with generically-derived `Strengthen` instances, you'll get a precise zoom-in of exactly where each error occurred.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenS :: forall (p :: k0). String -> String -> String -> String -> Natural -> S1 mw (Rec0 w) p -> (Natural, Validation (NonEmpty StrengthenError) (S1 ms (Rec0 s) p)) Source #
GStrengthenS (S1 mw (Rec0 w) :: k -> Type) (S1 ms (Rec0 w) :: k -> Type) Source #	Special case: if source and target types are equal, copy the value through.
Instance details Defined in Strongweak.Generic.Strengthen Methods gstrengthenS :: forall (p :: k0). String -> String -> String -> String -> Natural -> S1 mw (Rec0 w) p -> (Natural, Validation (NonEmpty StrengthenError) (S1 ms (Rec0 w) p)) Source #

selName'' :: forall s. Selector s => Maybe String Source #

Get the record name for a selector if present.

On the type level, a 'Maybe Symbol' is stored for record names. But the reification is done using fromMaybe "". So we have to inspect the resulting string to determine whether the field uses record syntax or not. (Silly.)

conName' :: forall c. Constructor c => String Source #

conName without the value (only used as a proxy). Lets us push our undefineds into one place.

datatypeName' :: forall d. Datatype d => String Source #

datatypeName without the value (only used as a proxy). Lets us push our undefineds into one place.

selName' :: forall s. Selector s => String Source #

selName without the value (only used as a proxy). Lets us push our undefineds into one place.