Safe Haskell	None
Language	Haskell2010

Elminator

Description

Generate Elm type definitions, encoders and decoders from Haskell data types.

  {-#Language ScopedTypeVariables#-}
  {-#Language FlexibleInstances#-}
  {-#Language DeriveAnyClass#-}
  {-#Language OverloadedStrings#-}

  module Lib  where

  import Elminator
  import GHC.Generics

  data SingleCon = SingleCon (Maybe Int) String deriving (Generic, ToHType)
  data WithMaybesPoly a b =
    WithMaybesPoly
      { mbpF1 :: Maybe a
      , mbpF2 :: Maybe b
      }
    deriving (Generic, ToHType)

Here is how we generate Elm source for the above defined types.

{-#Language OverloadedStrings#-}
{-#Language TemplateHaskell#-}

module CodeGen where

import Data.Proxy
import Elminator
import Data.Text

import Lib

elmSource :: Text
elmSource = $(generateFor Elm19 myDefaultOptions (Just "./elm-app/src/Autogen.elm") $ do
  include (Proxy :: Proxy SingleCon) $ Everything Mono
  include (Proxy :: Proxy (WithMaybesPoly (Maybe String) Float)) $ Definiton Poly

Synopsis

include :: ToHType a => Proxy a -> GenOption -> Builder
generateFor :: ElmVersion -> Options -> Maybe FilePath -> Builder -> Q Exp
data ElmVersion = Elm19
data HType
- = HUDef UDefData
- | HMaybe HType
- | HList HType
- | HPrimitive MData
- | HRecursive MData
- | HExternal ExInfo [HType]
class ToHType f where
- toHType :: Proxy f -> HState HType
data ExItem = ExItem {
- extModuleName :: Text
- extSymbol :: Text
}
data ExInfo = ExInfo {
- exType :: ExItem
- exEncoder :: Maybe ExItem
- exDecoder :: Maybe ExItem
}
type Builder = State GenConfig ()
data GenOption
- = Definiton PolyConfig
- | EncoderDecoder
- | Everything PolyConfig
data PolyConfig
- = Mono
- | Poly

Documentation

include :: ToHType a => Proxy a -> GenOption -> Builder Source #

Include the elm source for the Haskell type specified by the proxy argument. The second argument decides which components will be included and if the generated type will be polymorphic.

generateFor :: ElmVersion -> Options -> Maybe FilePath -> Builder -> Q Exp Source #

Return the generated Elm code in a template haskell splice and optionally write to a Elm source file at the same time. The second argument is the Options type from Aeson library. Use include calls to build the Builder value.

data ElmVersion Source #

Specify Elm version to generate code for

Constructors

Elm19

data HType Source #

This type holds the type information we get from generics. Only the HExternal constructor is supposed to be used by the programmer to implement ToHType instances for entites that are predefined in Elm. A sample can be seen below.

Here, let `MyExtType a b` be a type which has the corresponding type, encoders and decoders predefined in Elm in a module named Lib. Here is how you can implement a ToHType instance for this type so that your autogenerated types can have fields of type `MyExtType a b`.

  instance (ToHType a, ToHType b) => ToHType (MyExtType a b) where
    toHType _ = do
      ha <- toHType (Proxy :: Proxy a)
      hb <- toHType (Proxy :: Proxy b)
      pure $
        HExternal
          (ExInfo
            (ExItem "Lib" "MyExtType") 
            (Just $ ExItem "Lib" "encodeMyExtType")
            (Just $ ExItem "Lib" "decodeMyExtType"))
          [ha, hb]

Constructors

HUDef UDefData
HMaybe HType
HList HType
HPrimitive MData
HRecursive MData
HExternal ExInfo [HType]

Instances

Show HType Source #
Instance details Defined in Elminator.Generics.Simple Methods showsPrec :: Int -> HType -> ShowS # show :: HType -> String # showList :: [HType] -> ShowS #

class ToHType f where Source #

Minimal complete definition

Nothing

Methods

toHType :: Proxy f -> HState HType Source #

toHType :: (ToHTArgs (ExtractTArgs f), Generic f, ToHType_ (Rep f)) => Proxy f -> HState HType Source #

Instances

ToHType Bool Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy Bool -> HState HType Source #
ToHType Char Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy Char -> HState HType Source #
ToHType Float Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy Float -> HState HType Source #
ToHType Int Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy Int -> HState HType Source #
ToHType () Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy () -> HState HType Source #
ToHType a => ToHType [a] Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy [a] -> HState HType Source #
ToHType a => ToHType (Maybe a) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (Maybe a) -> HState HType Source #
(ToHType a, ToHType b) => ToHType (Either a b) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (Either a b) -> HState HType Source #
(ToHType a1, ToHType a2) => ToHType (a1, a2) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2) -> HState HType Source #
(ToHType a1, ToHType a2, ToHType a3) => ToHType (a1, a2, a3) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2, a3) -> HState HType Source #
(ToHType a1, ToHType a2, ToHType a3, ToHType a4) => ToHType (a1, a2, a3, a4) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2, a3, a4) -> HState HType Source #
(ToHType a1, ToHType a2, ToHType a3, ToHType a4, ToHType a5) => ToHType (a1, a2, a3, a4, a5) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2, a3, a4, a5) -> HState HType Source #
(ToHType a1, ToHType a2, ToHType a3, ToHType a4, ToHType a5, ToHType a6) => ToHType (a1, a2, a3, a4, a5, a6) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2, a3, a4, a5, a6) -> HState HType Source #
(ToHType a1, ToHType a2, ToHType a3, ToHType a4, ToHType a5, ToHType a6, ToHType a7) => ToHType (a1, a2, a3, a4, a5, a6, a7) Source #
Instance details Defined in Elminator.Generics.Simple Methods toHType :: Proxy (a1, a2, a3, a4, a5, a6, a7) -> HState HType Source #

data ExItem Source #

Constructors

ExItem
Fields extModuleName :: Text extSymbol :: Text

Instances

Eq ExItem Source #
Instance details Defined in Elminator.Generics.Simple Methods (==) :: ExItem -> ExItem -> Bool # (/=) :: ExItem -> ExItem -> Bool #
Show ExItem Source #
Instance details Defined in Elminator.Generics.Simple Methods showsPrec :: Int -> ExItem -> ShowS # show :: ExItem -> String # showList :: [ExItem] -> ShowS #

data ExInfo Source #

Constructors

ExInfo
Fields exType :: ExItem exEncoder :: Maybe ExItem exDecoder :: Maybe ExItem

Instances

Eq ExInfo Source #
Instance details Defined in Elminator.Generics.Simple Methods (==) :: ExInfo -> ExInfo -> Bool # (/=) :: ExInfo -> ExInfo -> Bool #
Show ExInfo Source #
Instance details Defined in Elminator.Generics.Simple Methods showsPrec :: Int -> ExInfo -> ShowS # show :: ExInfo -> String # showList :: [ExInfo] -> ShowS #

type Builder = State GenConfig () Source #

data GenOption Source #

Decides which among type definiton, encoder and decoder will be included for a type. The poly config value decides wether the included type definition will be polymorphic.

Constructors

Definiton PolyConfig
EncoderDecoder
Everything PolyConfig

Instances

Show GenOption Source #
Instance details Defined in Elminator.Lib Methods showsPrec :: Int -> GenOption -> ShowS # show :: GenOption -> String # showList :: [GenOption] -> ShowS #

data PolyConfig Source #

Decides wether the type definition will be polymorphic.

Constructors

Mono
Poly

Instances

Show PolyConfig Source #
Instance details Defined in Elminator.Lib Methods showsPrec :: Int -> PolyConfig -> ShowS # show :: PolyConfig -> String # showList :: [PolyConfig] -> ShowS #