Elmental

Documentation

class ElmKind (KindOf x) => ElmDeclarable x where

Class mapping a Haskell type constructor x :: k to an Elm type constructor.

You can define instances for this class for any Haskell data / newtype constructor, be it unapplied, partially applied or fully applied, provided that its kind is not Elm-compatible (i.e., not higher-kinded).

For example:

   data SomeHKT f a = SomeHKT (f a)

   instance ElmDeclarable ((Type -> Type) -> Type) SomeHKT -- Not OK: SomeHKT is higher-kinded.
   instance ElmDeclarable (Type -> Type) (SomeHKT Maybe) -- OK
   instance ElmDeclarable Type (SomeHKT Maybe Int) -- OK

   instance ElmDeclarable [] -- OK
   instance ElmDeclarable [Char] -- OK

Minimal complete definition

Nothing

Methods

mapTo :: ElmMapping

Elm mapping information.

Contains the name location of the type and its encoder decoder. Can be overridden.

Example:

   instance ElmDeclarable Type [Char] where
     mapTo = ElmMapping
       { typeName = String
       , moduleName = Nothing
       , encoderLocation = Just $ SymbolLocation
           { symbolName = "string"
           , moduleName = Json.Encode
           }
       , decoderLocation = Just $ SymbolLocation
           { symbolName = "string"
           , moduleName = Json.Decode
           }
       , args = []
       }
 

default mapTo :: HasSymbolInfo x => ElmMapping

mkTyRef :: PList (NParams (KindOf x)) TyRef -> TyRef

Internal function. You should not have to define this method yourself.

default mkTyRef :: PList (NParams (KindOf x)) TyRef -> TyRef

Instances

(ElmDeclarable t, ElmDeclarable x) => ElmDeclarable (x t :: k)

Instance for applied type constructors.

Necessary to traverse the list of type constructors down to the root when constructing type references to applied type constructors.

Defined in Elmental

Methods

mapTo :: ElmMapping

mkTyRef :: PList (NParams (KindOf (x t))) TyRef -> TyRef

type HasElmStructure k x = HasElmStructure' k x (RepK x)

data ElmMapping

Contains the mapping of Haskell type constructor to an Elm type constructor, and potentially the location of its encoder / decoder.

Constructors

ElmMapping

Fields

• typeName :: TypeName

  Name of the corresponding Elm datatype.

• moduleName :: Maybe ModuleName

  Name of the module this type should be imported from / generated in.

  Can be set to Nothing for core Elm types (List, Bool, String, ...) which don't require explicit imports.

• encoderLocation :: Maybe SymbolLocation

  Location of the encoder for this type.

  Must be set if you want to generate it, or to generate encoders depending on it.

• decoderLocation :: Maybe SymbolLocation

  Location of the decoder for this type.

  Must be set if you want to generate it, or to generate encoders depending on it.

• args :: [ElmMapping]

  Arguments supplied to the type constructor.

• isTypeAlias :: Bool

  Indicates whether the generated Elm datataype should be a type alias

• urlPiece :: Maybe SymbolLocation

  Location of the URL piece builder / parser for this type.

• queryParam :: Maybe SymbolLocation

  Location of the query param builder / parser for this type.

Instances

Show ElmMapping

Defined in Elmental.ElmStructure

Methods

showsPrec :: Int -> ElmMapping -> ShowS

show :: ElmMapping -> String

showList :: [ElmMapping] -> ShowS

Eq ElmMapping

Defined in Elmental.ElmStructure

Methods

(==) :: ElmMapping -> ElmMapping -> Bool

(/=) :: ElmMapping -> ElmMapping -> Bool

Ord ElmMapping

Defined in Elmental.ElmStructure

Methods

compare :: ElmMapping -> ElmMapping -> Ordering

(<) :: ElmMapping -> ElmMapping -> Bool

(<=) :: ElmMapping -> ElmMapping -> Bool

(>) :: ElmMapping -> ElmMapping -> Bool

(>=) :: ElmMapping -> ElmMapping -> Bool

max :: ElmMapping -> ElmMapping -> ElmMapping

min :: ElmMapping -> ElmMapping -> ElmMapping

type HasSymbolInfo x = (KnownSymbol (GetTypeNameG (RepK x)), KnownSymbol (GetModuleNameG (RepK x)))

type ElmKind k = ElmKindB k ~ True

Constraint establishing that a kind is valid in Elm.

defaultMapping :: forall x. HasSymbolInfo x => ElmMapping

getElmStructure :: forall {k} (x :: k). HasElmStructure k x => DatatypeStructure x

Extract the structure of the representation of a datatype in Elm.

Used by code generation.

getTypeName :: forall x. ElmDeclarable x => Text

getModuleName :: forall x. ElmDeclarable x => Maybe Text

getMapping :: forall x. ElmDeclarable x => ElmMapping

setModule :: Text -> ElmMapping -> ElmMapping

Overrides / sets the module name everywhere in a mapping. Often useful in conjunction wit defaultMapping.

module Elmental.ElmStructure