Moduleoptics-core-0.4.2Haskell2010

Optics.Internal.Generic.TypeLevel

This module is intended for internal use only, and may change without warning in subsequent releases.

Contents

Pathing
Names
Positions
Misc

Synopsis

data PathTree
data Path
family GetFieldPaths
family GetNamePath
family GetPositionPaths
family GetPositionPath
family HideReps
family AnyHasPath
family NoGenericError

Packageoptics-core-0.4.2
Exports9
LanguageHaskell2010
LicenceBSD-3-Clause
SourceTypeLevel.hs

Pathing

datadata PathTree e

Source#

A map that allows reaching a specific field in a generic representation of a data type. Computed up front by generic optics for early error reporting and efficient data traversal.

Constructors

PathNode (PathTree e) (PathTree e)
PathLeaf (Either e [Path])

datadata Path

PathLeft PathRight

Instances17GAffineFieldMaybe, GSetFieldProd, GConstructorSum, GFieldProd, …

r ~ b => GSetFieldProd '[] (M1 S m (Rec0 a)) (M1 S m (Rec0 b)) rDefined in optics-core-0.4.2 · Optics.Internal.Generic
GConstructorTuple g h a b => GConstructorSum '[] (M1 C m g) (M1 C m h) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(r ~ a, s ~ b) => GFieldProd '[] (M1 S m (Rec0 a)) (M1 S m (Rec0 b)) r sDefined in optics-core-0.4.2 · Optics.Internal.Generic
GFieldProd prodPath g h a b => GAffineFieldMaybe ('Right prodPath) g h a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
g ~ h => GAffineFieldMaybe ('Left name) g h a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GSetFieldProd path g1 h1 b => GSetFieldProd ('PathLeft ': path) (g1 :*: g2) (h1 :*: g2) bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GSetFieldProd path g2 h2 b => GSetFieldProd ('PathRight ': path) (g1 :*: g2) (g1 :*: h2) bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GSetFieldProd path g1 h1 b, g2 ~ h2) => GSetFieldProd ('PathLeft ': path) (g1 :*: g2) (h1 :*: h2) bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GSetFieldProd path g2 h2 b, g1 ~ h1) => GSetFieldProd ('PathRight ': path) (g1 :*: g2) (h1 :*: h2) bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GConstructorSum path g1 h1 a b => GConstructorSum ('PathLeft ': path) (g1 :+: g2) (h1 :+: g2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GConstructorSum path g2 h2 a b => GConstructorSum ('PathRight ': path) (g1 :+: g2) (g1 :+: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GConstructorSum path g1 h1 a b, g2 ~ h2) => GConstructorSum ('PathLeft ': path) (g1 :+: g2) (h1 :+: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GConstructorSum path g2 h2 a b, g1 ~ h1) => GConstructorSum ('PathRight ': path) (g1 :+: g2) (h1 :+: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GFieldProd path g1 h1 a b => GFieldProd ('PathLeft ': path) (g1 :*: g2) (h1 :*: g2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
GFieldProd path g2 h2 a b => GFieldProd ('PathRight ': path) (g1 :*: g2) (g1 :*: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GFieldProd path g1 h1 a b, g2 ~ h2) => GFieldProd ('PathLeft ': path) (g1 :*: g2) (h1 :*: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic
(GFieldProd path g2 h2 a b, g1 ~ h1) => GFieldProd ('PathRight ': path) (g1 :*: g2) (h1 :*: h2) a bDefined in optics-core-0.4.2 · Optics.Internal.Generic

Names

familytype family GetFieldPaths (s :: t) (name :: Symbol) (g :: k -> Type) :: PathTree Symbol where

Source#

Compute paths to a field with a specific name.

Equations

GetFieldPaths s name (M1 D _1 g) = GetFieldPaths s name g
GetFieldPaths s name (g1 :+: g2) = 'PathNode (GetFieldPaths s name g1) (GetFieldPaths s name g2)
GetFieldPaths s name (M1 C _1 g) = 'PathLeaf (GetNamePath name g '[])
GetFieldPaths s name V1 = TypeError (('Text "Type " ':<>: QuoteType s) ':<>: 'Text " has no data constructors")

familytype family GetNamePath (name :: Symbol) (g :: k -> Type) (acc :: [Path]) :: Either Symbol [Path] where

Source#

Compute path to a constructor in a sum or a field in a product with a specific name.

Equations

GetNamePath name (M1 D _1 g) acc = GetNamePath name g acc
GetNamePath name (M1 C ('MetaCons name _1 _2) _3) acc = 'Right (Reverse acc '[])
GetNamePath name (g1 :+: g2) acc = FirstRight (GetNamePath name g1 ('PathLeft ': acc)) (GetNamePath name g2 ('PathRight ': acc))
GetNamePath name (M1 S ('MetaSel ('Just name) _1 _2 _3) _4) acc = 'Right (Reverse acc '[])
GetNamePath name (g1 :*: g2) acc = FirstRight (GetNamePath name g1 ('PathLeft ': acc)) (GetNamePath name g2 ('PathRight ': acc))
GetNamePath name _1 _2 = 'Left name

Positions

familytype family GetPositionPaths (s :: t) (pos :: Nat) (g :: k -> Type) :: PathTree (Nat, Nat) where

Source#

Compute paths to a field at a specific position.

Equations

GetPositionPaths s pos (M1 D _1 g) = GetPositionPaths s pos g
GetPositionPaths s pos (g1 :+: g2) = 'PathNode (GetPositionPaths s pos g1) (GetPositionPaths s pos g2)
GetPositionPaths s pos (M1 C _1 g) = 'PathLeaf (GetPositionPath pos g 0 '[])
GetPositionPaths s pos V1 = TypeError (('Text "Type " ':<>: QuoteType s) ':<>: 'Text " has no data constructors")

familytype family GetPositionPath (pos :: Nat) (g :: k -> Type) (k1 :: Nat) (acc :: [Path]) :: Either (Nat, Nat) [Path] where

Source#

Compute path to a constructor in a sum or a field in a product at a specific position.

Equations

GetPositionPath pos (M1 D _1 g) k2 acc = GetPositionPath pos g k2 acc
GetPositionPath pos (M1 C _1 _2) k2 acc = If (pos == (k2 + 1)) ('Right (Reverse acc '[])) ('Left '(pos, k2 + 1))
GetPositionPath pos (g1 :+: g2) k2 acc = ContinueWhenLeft (GetPositionPath pos g1 k2 ('PathLeft ': acc)) g2 acc
GetPositionPath pos (M1 S _1 _2) k2 acc = If (pos == (k2 + 1)) ('Right (Reverse acc '[])) ('Left '(pos, k2 + 1))
GetPositionPath pos (g1 :*: g2) k2 acc = ContinueWhenLeft (GetPositionPath pos g1 k2 ('PathLeft ': acc)) g2 acc
GetPositionPath pos _1 k2 _2 = 'Left '(pos, k2)

Misc

familytype family HideReps (g :: Type -> Type) (h :: Type -> Type) :: Constraint where

Source#

Generate bogus equality constraints that attempt to unify generic representations with this type in case there is an error such as missing field, constructor etc. so these huge types don't leak into error messages.

Equations

HideReps g h = (g ~ Void1, h ~ Void1)

familytype family AnyHasPath (path :: PathTree e) :: Bool where

Source#

Check if any leaf in the tree has a '[Path]'.

Equations

AnyHasPath ('PathNode path1 path2) = AnyHasPath path1 || AnyHasPath path2
AnyHasPath ('PathLeaf ('Right _1)) = 'True
AnyHasPath ('PathLeaf ('Left _1)) = 'False

familytype family NoGenericError (t1 :: t) :: k where

Equations

NoGenericError t2 = TypeError (('Text "Type " ':<>: QuoteType t2) ':<>: 'Text " doesn't have a Generic instance")