Module

Foreign.Generic

Package
purescript-foreign-generic
Repository
paf31/purescript-foreign-generic

#genericDecode Source

genericDecode :: forall a rep. Generic a rep => GenericDecode rep => Options -> Foreign -> F a

Read a value which has a Generic type.

#genericEncode Source

genericEncode :: forall a rep. Generic a rep => GenericEncode rep => Options -> a -> Foreign

Generate a Foreign value compatible with the genericDecode function.

#decodeJSON Source

decodeJSON :: forall a. Decode a => String -> F a

Decode a JSON string using a Decode instance.

#encodeJSON Source

encodeJSON :: forall a. Encode a => a -> String

Encode a JSON string using an Encode instance.

#genericDecodeJSON Source

genericDecodeJSON :: forall a rep. Generic a rep => GenericDecode rep => Options -> String -> F a

Read a value which has a Generic type from a JSON String

#genericEncodeJSON Source

genericEncodeJSON :: forall a rep. Generic a rep => GenericEncode rep => Options -> a -> String

Write a value which has a Generic type as a JSON String

Re-exports from Foreign

#Foreign Source

data Foreign :: Type

A type for foreign data.

Foreign data is data from any external unknown or unreliable source, for which it cannot be guaranteed that the runtime representation conforms to that of any particular type.

Suitable applications of Foreign are

  • To represent responses from web services
  • To integrate with external JavaScript libraries.

#F Source

type F = Except MultipleErrors

An error monad, used in this library to encode possible failures when dealing with foreign data.

The Alt instance for Except allows us to accumulate errors, unlike Either, which preserves only the last error.

Re-exports from Foreign.Generic.Class

#SumEncoding Source

data SumEncoding

The encoding of sum types for your type. TaggedObjects will be encoded in the form { [tagFieldName]: "ConstructorTag", [contentsFieldName]: "Contents"}. constructorTagTransform can be provided to transform the constructor tag to a form you use, e.g. toLower/toUpper.

Constructors

#Options Source

type Options = { fieldTransform :: String -> String, sumEncoding :: SumEncoding, unwrapSingleArguments :: Boolean, unwrapSingleConstructors :: Boolean }

Encoding/Decoding options which can be used to customize Decode and Encode instances which are derived via Generic (see genericEncode and genericDecode).

#Decode Source

class Decode a  where

The Decode class is used to generate decoding functions of the form Foreign -> F a using generics-rep deriving.

First, derive Generic for your data:

import Data.Generic.Rep

data MyType = MyType ...

derive instance genericMyType :: Generic MyType _

You can then use the genericDecode and genericDecodeJSON functions to decode your foreign/JSON-encoded data.

Members

Instances

#Encode Source

class Encode a  where

The Encode class is used to generate encoding functions of the form a -> Foreign using generics-rep deriving.

First, derive Generic for your data:

import Data.Generic.Rep

data MyType = MyType ...

derive instance genericMyType :: Generic MyType _

You can then use the genericEncode and genericEncodeJSON functions to encode your data as JSON.

Members

Instances

#defaultOptions Source

defaultOptions :: Options

Default decoding/encoding options:

  • Represent sum types as records with tag and contents fields
  • Unwrap single arguments
  • Don't unwrap single constructors
  • Use the constructor names as-is
  • Use the field names as-is