{-# OPTIONS_GHC -fno-warn-redundant-constraints #-}
{-# LANGUAGE AllowAmbiguousTypes #-}
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE TypeSynonymInstances #-}
{-# LANGUAGE UndecidableInstances #-}
module Elm.Generic
(
Elm (..)
, elmRef
, elmNewtype
, GenericElmDefinition (..)
, GenericElmConstructors (..)
, GenericElmFields (..)
, GenericConstructor (..)
, toElmConstructor
, HasNoTypeVars
, TypeVarsError
, HasLessThanEightUnnamedFields
, FieldsError
, CheckFields
, Max
, HasNoNamedSum
, NamedSumError
, CheckNamedSum
, CheckConst
, stripTypeNamePrefix
) where
import Data.Char (isLower, toLower)
import Data.Int (Int16, Int32, Int8)
import Data.Kind (Constraint, Type)
import Data.List.NonEmpty (NonEmpty (..))
import Data.Proxy (Proxy (..))
import Data.Text (Text)
import Data.Time.Clock (UTCTime)
import Data.Type.Bool (If, type (||))
import Data.Void (Void)
import Data.Word (Word16, Word32, Word8)
import GHC.Generics ((:*:), (:+:), C1, Constructor (..), D1, Datatype (..), Generic (..), M1 (..),
Meta (..), Rec0, S1, Selector (..), U1)
import GHC.TypeLits (ErrorMessage (..), Nat, TypeError)
import GHC.TypeNats (type (+), type (<=?))
import Elm.Ast (ElmAlias (..), ElmConstructor (..), ElmDefinition (..), ElmPrim (..),
ElmRecordField (..), ElmType (..), TypeName (..), TypeRef (..), definitionToRef)
import qualified Data.Text as T
import qualified Data.Text.Lazy as LT (Text)
import qualified GHC.Generics as Generic (from)
class Elm a where
toElmDefinition :: Proxy a -> ElmDefinition
default toElmDefinition
:: ( HasNoTypeVars a
, HasLessThanEightUnnamedFields a
, HasNoNamedSum a
, Generic a
, GenericElmDefinition (Rep a)
)
=> Proxy a
-> ElmDefinition
toElmDefinition Proxy a
_ = Rep a Any -> ElmDefinition
forall k (f :: k -> *) (a :: k).
GenericElmDefinition f =>
f a -> ElmDefinition
genericToElmDefinition
(Rep a Any -> ElmDefinition) -> Rep a Any -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ a -> Rep a Any
forall a x. Generic a => a -> Rep a x
Generic.from ([Char] -> a
forall a. HasCallStack => [Char] -> a
error [Char]
"Proxy for generic elm was evaluated" :: a)
elmRef :: forall a . Elm a => TypeRef
elmRef :: TypeRef
elmRef = ElmDefinition -> TypeRef
definitionToRef (ElmDefinition -> TypeRef) -> ElmDefinition -> TypeRef
forall a b. (a -> b) -> a -> b
$ Proxy a -> ElmDefinition
forall a. Elm a => Proxy a -> ElmDefinition
toElmDefinition (Proxy a -> ElmDefinition) -> Proxy a -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ Proxy a
forall k (t :: k). Proxy t
Proxy @a
instance Elm () where toElmDefinition :: Proxy () -> ElmDefinition
toElmDefinition Proxy ()
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmUnit
instance Elm Void where toElmDefinition :: Proxy Void -> ElmDefinition
toElmDefinition Proxy Void
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmNever
instance Elm Bool where toElmDefinition :: Proxy Bool -> ElmDefinition
toElmDefinition Proxy Bool
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmBool
instance Elm Char where toElmDefinition :: Proxy Char -> ElmDefinition
toElmDefinition Proxy Char
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmChar
instance Elm Int where toElmDefinition :: Proxy Int -> ElmDefinition
toElmDefinition Proxy Int
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Int8 where toElmDefinition :: Proxy Int8 -> ElmDefinition
toElmDefinition Proxy Int8
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Int16 where toElmDefinition :: Proxy Int16 -> ElmDefinition
toElmDefinition Proxy Int16
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Int32 where toElmDefinition :: Proxy Int32 -> ElmDefinition
toElmDefinition Proxy Int32
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Word where toElmDefinition :: Proxy Word -> ElmDefinition
toElmDefinition Proxy Word
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Word8 where toElmDefinition :: Proxy Word8 -> ElmDefinition
toElmDefinition Proxy Word8
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Word16 where toElmDefinition :: Proxy Word16 -> ElmDefinition
toElmDefinition Proxy Word16
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Word32 where toElmDefinition :: Proxy Word32 -> ElmDefinition
toElmDefinition Proxy Word32
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmInt
instance Elm Float where toElmDefinition :: Proxy Float -> ElmDefinition
toElmDefinition Proxy Float
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmFloat
instance Elm Double where toElmDefinition :: Proxy Double -> ElmDefinition
toElmDefinition Proxy Double
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmFloat
instance Elm Text where toElmDefinition :: Proxy Text -> ElmDefinition
toElmDefinition Proxy Text
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmString
instance Elm LT.Text where toElmDefinition :: Proxy Text -> ElmDefinition
toElmDefinition Proxy Text
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmString
instance Elm UTCTime where toElmDefinition :: Proxy UTCTime -> ElmDefinition
toElmDefinition Proxy UTCTime
_ = ElmPrim -> ElmDefinition
DefPrim ElmPrim
ElmTime
instance Elm a => Elm (Maybe a) where
toElmDefinition :: Proxy (Maybe a) -> ElmDefinition
toElmDefinition Proxy (Maybe a)
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> ElmPrim
ElmMaybe (TypeRef -> ElmPrim) -> TypeRef -> ElmPrim
forall a b. (a -> b) -> a -> b
$ Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a
instance (Elm a, Elm b) => Elm (Either a b) where
toElmDefinition :: Proxy (Either a b) -> ElmDefinition
toElmDefinition Proxy (Either a b)
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> TypeRef -> ElmPrim
ElmResult (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a) (Elm b => TypeRef
forall a. Elm a => TypeRef
elmRef @b)
instance (Elm a, Elm b) => Elm (a, b) where
toElmDefinition :: Proxy (a, b) -> ElmDefinition
toElmDefinition Proxy (a, b)
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> TypeRef -> ElmPrim
ElmPair (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a) (Elm b => TypeRef
forall a. Elm a => TypeRef
elmRef @b)
instance (Elm a, Elm b, Elm c) => Elm (a, b, c) where
toElmDefinition :: Proxy (a, b, c) -> ElmDefinition
toElmDefinition Proxy (a, b, c)
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> TypeRef -> TypeRef -> ElmPrim
ElmTriple (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a) (Elm b => TypeRef
forall a. Elm a => TypeRef
elmRef @b) (Elm c => TypeRef
forall a. Elm a => TypeRef
elmRef @c)
instance Elm a => Elm [a] where
toElmDefinition :: Proxy [a] -> ElmDefinition
toElmDefinition Proxy [a]
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> ElmPrim
ElmList (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a)
instance Elm a => Elm (NonEmpty a) where
toElmDefinition :: Proxy (NonEmpty a) -> ElmDefinition
toElmDefinition Proxy (NonEmpty a)
_ = ElmPrim -> ElmDefinition
DefPrim (ElmPrim -> ElmDefinition) -> ElmPrim -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ TypeRef -> ElmPrim
ElmList (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a)
elmNewtype :: forall a . Elm a => Text -> Text -> ElmDefinition
elmNewtype :: Text -> Text -> ElmDefinition
elmNewtype Text
typeName Text
fieldName = ElmAlias -> ElmDefinition
DefAlias (ElmAlias -> ElmDefinition) -> ElmAlias -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ ElmAlias :: Text -> NonEmpty ElmRecordField -> Bool -> ElmAlias
ElmAlias
{ elmAliasName :: Text
elmAliasName = Text
typeName
, elmAliasFields :: NonEmpty ElmRecordField
elmAliasFields = TypeRef -> Text -> ElmRecordField
ElmRecordField (Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a) Text
fieldName ElmRecordField -> [ElmRecordField] -> NonEmpty ElmRecordField
forall a. a -> [a] -> NonEmpty a
:| []
, elmAliasIsNewtype :: Bool
elmAliasIsNewtype = Bool
True
}
class GenericElmDefinition (f :: k -> Type) where
genericToElmDefinition :: f a -> ElmDefinition
instance (Datatype d, GenericElmConstructors f) => GenericElmDefinition (D1 d f) where
genericToElmDefinition :: D1 d f a -> ElmDefinition
genericToElmDefinition D1 d f a
datatype = case TypeName -> f a -> NonEmpty GenericConstructor
forall k (f :: k -> *) (a :: k).
GenericElmConstructors f =>
TypeName -> f a -> NonEmpty GenericConstructor
genericToElmConstructors (Text -> TypeName
TypeName Text
typeName) (D1 d f a -> f a
forall i (c :: Meta) k (f :: k -> *) (p :: k). M1 i c f p -> f p
unM1 D1 d f a
datatype) of
GenericConstructor
c :| [] -> case GenericConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor
toElmConstructor GenericConstructor
c of
Left NonEmpty ElmRecordField
fields -> ElmAlias -> ElmDefinition
DefAlias (ElmAlias -> ElmDefinition) -> ElmAlias -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ Text -> NonEmpty ElmRecordField -> Bool -> ElmAlias
ElmAlias Text
typeName NonEmpty ElmRecordField
fields Bool
elmIsNewtype
Right ElmConstructor
ctor -> ElmType -> ElmDefinition
DefType (ElmType -> ElmDefinition) -> ElmType -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ Text -> [Text] -> Bool -> NonEmpty ElmConstructor -> ElmType
ElmType Text
typeName [] Bool
elmIsNewtype (ElmConstructor
ctor ElmConstructor -> [ElmConstructor] -> NonEmpty ElmConstructor
forall a. a -> [a] -> NonEmpty a
:| [])
GenericConstructor
c :| [GenericConstructor]
cs -> case (GenericConstructor -> Maybe ElmConstructor)
-> NonEmpty GenericConstructor -> Maybe (NonEmpty ElmConstructor)
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
traverse (Either (NonEmpty ElmRecordField) ElmConstructor
-> Maybe ElmConstructor
forall l r. Either l r -> Maybe r
rightToMaybe (Either (NonEmpty ElmRecordField) ElmConstructor
-> Maybe ElmConstructor)
-> (GenericConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor)
-> GenericConstructor
-> Maybe ElmConstructor
forall b c a. (b -> c) -> (a -> b) -> a -> c
. GenericConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor
toElmConstructor) (GenericConstructor
c GenericConstructor
-> [GenericConstructor] -> NonEmpty GenericConstructor
forall a. a -> [a] -> NonEmpty a
:| [GenericConstructor]
cs) of
Maybe (NonEmpty ElmConstructor)
Nothing -> ElmType -> ElmDefinition
DefType (ElmType -> ElmDefinition) -> ElmType -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ Text -> [Text] -> Bool -> NonEmpty ElmConstructor -> ElmType
ElmType (Text
"ERROR_" Text -> Text -> Text
forall a. Semigroup a => a -> a -> a
<> Text
typeName) [] Bool
False (Text -> [TypeRef] -> ElmConstructor
ElmConstructor Text
"ERROR" [] ElmConstructor -> [ElmConstructor] -> NonEmpty ElmConstructor
forall a. a -> [a] -> NonEmpty a
:| [])
Just NonEmpty ElmConstructor
ctors -> ElmType -> ElmDefinition
DefType (ElmType -> ElmDefinition) -> ElmType -> ElmDefinition
forall a b. (a -> b) -> a -> b
$ Text -> [Text] -> Bool -> NonEmpty ElmConstructor -> ElmType
ElmType Text
typeName [] Bool
elmIsNewtype NonEmpty ElmConstructor
ctors
where
typeName :: Text
typeName :: Text
typeName = [Char] -> Text
T.pack ([Char] -> Text) -> [Char] -> Text
forall a b. (a -> b) -> a -> b
$ D1 d f a -> [Char]
forall k (d :: k) k1 (t :: k -> (k1 -> *) -> k1 -> *)
(f :: k1 -> *) (a :: k1).
Datatype d =>
t d f a -> [Char]
datatypeName D1 d f a
datatype
elmIsNewtype :: Bool
elmIsNewtype :: Bool
elmIsNewtype = D1 d f a -> Bool
forall k (d :: k) k1 (t :: k -> (k1 -> *) -> k1 -> *)
(f :: k1 -> *) (a :: k1).
Datatype d =>
t d f a -> Bool
isNewtype D1 d f a
datatype
rightToMaybe :: Either l r -> Maybe r
rightToMaybe :: Either l r -> Maybe r
rightToMaybe = (l -> Maybe r) -> (r -> Maybe r) -> Either l r -> Maybe r
forall a c b. (a -> c) -> (b -> c) -> Either a b -> c
either (Maybe r -> l -> Maybe r
forall a b. a -> b -> a
const Maybe r
forall a. Maybe a
Nothing) r -> Maybe r
forall a. a -> Maybe a
Just
data GenericConstructor = GenericConstructor
{ GenericConstructor -> Text
genericConstructorName :: !Text
, GenericConstructor -> [(TypeRef, Maybe Text)]
genericConstructorFields :: ![(TypeRef, Maybe Text)]
}
toElmConstructor :: GenericConstructor -> Either (NonEmpty ElmRecordField) ElmConstructor
toElmConstructor :: GenericConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor
toElmConstructor GenericConstructor{[(TypeRef, Maybe Text)]
Text
genericConstructorFields :: [(TypeRef, Maybe Text)]
genericConstructorName :: Text
genericConstructorFields :: GenericConstructor -> [(TypeRef, Maybe Text)]
genericConstructorName :: GenericConstructor -> Text
..} = case [(TypeRef, Maybe Text)]
genericConstructorFields of
[] -> ElmConstructor -> Either (NonEmpty ElmRecordField) ElmConstructor
forall a b. b -> Either a b
Right (ElmConstructor -> Either (NonEmpty ElmRecordField) ElmConstructor)
-> ElmConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor
forall a b. (a -> b) -> a -> b
$ Text -> [TypeRef] -> ElmConstructor
ElmConstructor Text
genericConstructorName []
(TypeRef, Maybe Text)
f:[(TypeRef, Maybe Text)]
fs -> case ((TypeRef, Maybe Text) -> Maybe ElmRecordField)
-> NonEmpty (TypeRef, Maybe Text)
-> Maybe (NonEmpty ElmRecordField)
forall (t :: * -> *) (f :: * -> *) a b.
(Traversable t, Applicative f) =>
(a -> f b) -> t a -> f (t b)
traverse (TypeRef, Maybe Text) -> Maybe ElmRecordField
toRecordField ((TypeRef, Maybe Text)
f (TypeRef, Maybe Text)
-> [(TypeRef, Maybe Text)] -> NonEmpty (TypeRef, Maybe Text)
forall a. a -> [a] -> NonEmpty a
:| [(TypeRef, Maybe Text)]
fs) of
Maybe (NonEmpty ElmRecordField)
Nothing -> ElmConstructor -> Either (NonEmpty ElmRecordField) ElmConstructor
forall a b. b -> Either a b
Right (ElmConstructor -> Either (NonEmpty ElmRecordField) ElmConstructor)
-> ElmConstructor
-> Either (NonEmpty ElmRecordField) ElmConstructor
forall a b. (a -> b) -> a -> b
$ Text -> [TypeRef] -> ElmConstructor
ElmConstructor Text
genericConstructorName ([TypeRef] -> ElmConstructor) -> [TypeRef] -> ElmConstructor
forall a b. (a -> b) -> a -> b
$ ((TypeRef, Maybe Text) -> TypeRef)
-> [(TypeRef, Maybe Text)] -> [TypeRef]
forall a b. (a -> b) -> [a] -> [b]
map (TypeRef, Maybe Text) -> TypeRef
forall a b. (a, b) -> a
fst [(TypeRef, Maybe Text)]
genericConstructorFields
Just NonEmpty ElmRecordField
fields -> NonEmpty ElmRecordField
-> Either (NonEmpty ElmRecordField) ElmConstructor
forall a b. a -> Either a b
Left NonEmpty ElmRecordField
fields
where
toRecordField :: (TypeRef, Maybe Text) -> Maybe ElmRecordField
toRecordField :: (TypeRef, Maybe Text) -> Maybe ElmRecordField
toRecordField (TypeRef
typeRef, Maybe Text
maybeFieldName) = TypeRef -> Text -> ElmRecordField
ElmRecordField TypeRef
typeRef (Text -> ElmRecordField) -> Maybe Text -> Maybe ElmRecordField
forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
<$> Maybe Text
maybeFieldName
class GenericElmConstructors (f :: k -> Type) where
genericToElmConstructors
:: TypeName
-> f a
-> NonEmpty GenericConstructor
instance (GenericElmConstructors f, GenericElmConstructors g) => GenericElmConstructors (f :+: g) where
genericToElmConstructors :: TypeName -> (:+:) f g a -> NonEmpty GenericConstructor
genericToElmConstructors TypeName
name (:+:) f g a
_ =
TypeName -> f Any -> NonEmpty GenericConstructor
forall k (f :: k -> *) (a :: k).
GenericElmConstructors f =>
TypeName -> f a -> NonEmpty GenericConstructor
genericToElmConstructors TypeName
name ([Char] -> f p
forall a. HasCallStack => [Char] -> a
error [Char]
"'f :+:' is evaluated" :: f p)
NonEmpty GenericConstructor
-> NonEmpty GenericConstructor -> NonEmpty GenericConstructor
forall a. Semigroup a => a -> a -> a
<> TypeName -> g Any -> NonEmpty GenericConstructor
forall k (f :: k -> *) (a :: k).
GenericElmConstructors f =>
TypeName -> f a -> NonEmpty GenericConstructor
genericToElmConstructors TypeName
name ([Char] -> g p
forall a. HasCallStack => [Char] -> a
error [Char]
"':+: g' is evaluated" :: g p)
instance (Constructor c, GenericElmFields f) => GenericElmConstructors (C1 c f) where
genericToElmConstructors :: TypeName -> C1 c f a -> NonEmpty GenericConstructor
genericToElmConstructors TypeName
name C1 c f a
constructor = GenericConstructor -> NonEmpty GenericConstructor
forall (f :: * -> *) a. Applicative f => a -> f a
pure (GenericConstructor -> NonEmpty GenericConstructor)
-> GenericConstructor -> NonEmpty GenericConstructor
forall a b. (a -> b) -> a -> b
$ Text -> [(TypeRef, Maybe Text)] -> GenericConstructor
GenericConstructor
([Char] -> Text
T.pack ([Char] -> Text) -> [Char] -> Text
forall a b. (a -> b) -> a -> b
$ C1 c f a -> [Char]
forall k (c :: k) k1 (t :: k -> (k1 -> *) -> k1 -> *)
(f :: k1 -> *) (a :: k1).
Constructor c =>
t c f a -> [Char]
conName C1 c f a
constructor)
(TypeName -> f a -> [(TypeRef, Maybe Text)]
forall k (f :: k -> *) (a :: k).
GenericElmFields f =>
TypeName -> f a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
name (f a -> [(TypeRef, Maybe Text)]) -> f a -> [(TypeRef, Maybe Text)]
forall a b. (a -> b) -> a -> b
$ C1 c f a -> f a
forall i (c :: Meta) k (f :: k -> *) (p :: k). M1 i c f p -> f p
unM1 C1 c f a
constructor)
class GenericElmFields (f :: k -> Type) where
genericToElmFields
:: TypeName
-> f a
-> [(TypeRef, Maybe Text)]
instance (GenericElmFields f, GenericElmFields g) => GenericElmFields (f :*: g) where
genericToElmFields :: TypeName -> (:*:) f g a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
name (:*:) f g a
_ =
TypeName -> f Any -> [(TypeRef, Maybe Text)]
forall k (f :: k -> *) (a :: k).
GenericElmFields f =>
TypeName -> f a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
name ([Char] -> f p
forall a. HasCallStack => [Char] -> a
error [Char]
"'f :*:' is evaluated" :: f p)
[(TypeRef, Maybe Text)]
-> [(TypeRef, Maybe Text)] -> [(TypeRef, Maybe Text)]
forall a. Semigroup a => a -> a -> a
<> TypeName -> g Any -> [(TypeRef, Maybe Text)]
forall k (f :: k -> *) (a :: k).
GenericElmFields f =>
TypeName -> f a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
name ([Char] -> g p
forall a. HasCallStack => [Char] -> a
error [Char]
"':*: g' is evaluated" :: g p)
instance GenericElmFields U1 where
genericToElmFields :: TypeName -> U1 a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
_ U1 a
_ = []
instance (Selector s, Elm a) => GenericElmFields (S1 s (Rec0 a)) where
genericToElmFields :: TypeName -> S1 s (Rec0 a) a -> [(TypeRef, Maybe Text)]
genericToElmFields TypeName
typeName S1 s (Rec0 a) a
selector = case S1 s (Rec0 a) a -> [Char]
forall k (s :: k) k1 (t :: k -> (k1 -> *) -> k1 -> *)
(f :: k1 -> *) (a :: k1).
Selector s =>
t s f a -> [Char]
selName S1 s (Rec0 a) a
selector of
[Char]
"" -> [(Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a, Maybe Text
forall a. Maybe a
Nothing)]
[Char]
name -> [(Elm a => TypeRef
forall a. Elm a => TypeRef
elmRef @a, Text -> Maybe Text
forall a. a -> Maybe a
Just (Text -> Maybe Text) -> Text -> Maybe Text
forall a b. (a -> b) -> a -> b
$ TypeName -> Text -> Text
stripTypeNamePrefix TypeName
typeName (Text -> Text) -> Text -> Text
forall a b. (a -> b) -> a -> b
$ [Char] -> Text
T.pack [Char]
name)]
stripTypeNamePrefix :: TypeName -> Text -> Text
stripTypeNamePrefix :: TypeName -> Text -> Text
stripTypeNamePrefix (TypeName Text
typeName) Text
fieldName =
case Text -> Text -> Maybe Text
T.stripPrefix (Text -> Text
headToLower Text
typeName) Text
fieldName of
Just Text
rest -> Text -> Text
leaveIfEmpty Text
rest
Maybe Text
Nothing -> Text -> Text
leaveIfEmpty ((Char -> Bool) -> Text -> Text
T.dropWhile Char -> Bool
isLower Text
fieldName)
where
headToLower :: Text -> Text
headToLower :: Text -> Text
headToLower Text
t = case Text -> Maybe (Char, Text)
T.uncons Text
t of
Maybe (Char, Text)
Nothing -> [Char] -> Text
forall a. HasCallStack => [Char] -> a
error [Char]
"Cannot use 'headToLower' on empty Text"
Just (Char
x, Text
xs) -> Char -> Text -> Text
T.cons (Char -> Char
toLower Char
x) Text
xs
leaveIfEmpty :: Text -> Text
leaveIfEmpty :: Text -> Text
leaveIfEmpty Text
rest = if Text -> Bool
T.null Text
rest then Text
fieldName else Text -> Text
headToLower Text
rest
type family HasNoTypeVars (f :: k) :: Constraint where
HasNoTypeVars (t a b c d e f) = TypeError (TypeVarsError t 6)
HasNoTypeVars (t a b c d e) = TypeError (TypeVarsError t 5)
HasNoTypeVars (t a b c d) = TypeError (TypeVarsError t 4)
HasNoTypeVars (t a b c) = TypeError (TypeVarsError t 3)
HasNoTypeVars (t a b) = TypeError (TypeVarsError t 2)
HasNoTypeVars (t a) = TypeError (TypeVarsError t 1)
HasNoTypeVars t = ()
type family TypeVarsError (t :: k) (n :: Nat) :: ErrorMessage where
TypeVarsError t n =
'Text "'elm-street' currently doesn't support Generic deriving of the 'Elm' typeclass"
':$$: 'Text "for data types with type variables. But '"
':<>: 'ShowType t ':<>: 'Text "' has " ':<>: 'ShowType n ':<>: 'Text " variables."
':$$: 'Text ""
':$$: 'Text "See the following issue for more details:"
':$$: 'Text " * https://github.com/Holmusk/elm-street/issues/45"
':$$: 'Text ""
type family HasLessThanEightUnnamedFields (f :: k) :: Constraint where
HasLessThanEightUnnamedFields t =
If (CheckFields (Rep t) <=? 8)
(() :: Constraint)
(TypeError (FieldsError t))
type family CheckFields (f :: k -> Type) :: Nat where
CheckFields (D1 _ f) = CheckFields f
CheckFields (f :+: g) = Max (CheckFields f) (CheckFields g)
CheckFields (C1 _ f) = CheckFields f
CheckFields (f :*: g) = CheckFields f + CheckFields g
CheckFields (S1 ('MetaSel ('Just _ ) _ _ _) _) = 0
CheckFields (S1 _ _) = 1
CheckFields _ = 0
type family Max (x :: Nat) (y :: Nat) :: Nat where
Max x y = If (x <=? y) y x
type family FieldsError (t :: k) :: ErrorMessage where
FieldsError t =
'Text "'elm-street' doesn't support Constructors with more than 8 unnamed fields."
':$$: 'Text "But '" ':<>: 'ShowType t ':<>: 'Text "' has more."
type family HasNoNamedSum (f :: k) :: Constraint where
HasNoNamedSum t =
If (CheckNamedSum (Rep t))
(TypeError (NamedSumError t))
(() :: Constraint)
type family CheckNamedSum (f :: k -> Type) :: Bool where
CheckNamedSum (D1 _ f) = CheckNamedSum f
CheckNamedSum (f :+: g) = CheckConst f || CheckConst g
CheckNamedSum _ = 'False
type family CheckConst (f :: k -> Type) :: Bool where
CheckConst (f :+: g) = CheckConst f || CheckConst g
CheckConst (C1 _ f) = CheckConst f
CheckConst (S1 ('MetaSel ('Just _ ) _ _ _) _) = 'True
CheckConst (f :*: g) = CheckConst f || CheckConst g
CheckConst _ = 'False
type family NamedSumError (t :: k) :: ErrorMessage where
NamedSumError t =
'Text "'elm-street' doesn't support Sum types with records."
':$$: 'Text "But '" ':<>: 'ShowType t ':<>: 'Text "' has records."