Jordan.FromJSON.Class

Parse JSON using finally-tagless style.

This provides JSON parsing as an abstract interface. This interface provides a way to parse JSON that is *inspectable* and has some nice properties: for example, we can use it to build a parser that directly parses your data structure, without building some intermediate value type!

Documentation

class (Applicative f, Representational f) => JSONObjectParser f where

A class for parsing JSON objects.

Minimal complete definition

parseFieldWith, parseFieldWithDefault

Methods

parseFieldWith

Arguments

:: Text

Label of the field. Will be parsed into escaped text, if need be.

-> (forall valueParser. JSONParser valueParser => valueParser a)

How to parse the field. Note the forall in this type signature: you cannot have this be specific to any particular implementation of parsing, to keep the parsing of a JSON abstract.

-> f a

Parse an object field with a given label, using a parser.

Note: in order to enable the generation of better documentation, use parseField instead if at all possible!

parseDescribeFieldWith

Arguments

:: Text

Field key to parse

-> Text

Description of the field

-> (forall valueParser. JSONParser valueParser => valueParser a)

Parser for the field

-> f a

parseField :: FromJSON v => Text -> f v

parseDescribeField :: FromJSON v => Text -> Text -> f v

parseFieldWithDefault

Arguments

:: Text

Label of the field.

-> (forall valueParser. JSONParser valueParser => valueParser a)

Parse the value from the field

-> a

Default value for the field

-> f a

Field in the object.

parseDescribeFieldWithDefault

Arguments

:: Text

Label of the field

-> Text

Description of the field

-> (forall valueParser. JSONParser valueParser => valueParser a)

Parser for the field

-> a

-> f a

class (Applicative f, Representational f) => JSONTupleParser f where

A class for parsing JSON arrays.

Minimal complete definition

consumeItemWith

Methods

consumeItemWith :: (forall valueParser. JSONParser valueParser => valueParser a) -> f a

Use a JSON parser to consume a single item of an array, then move onto the next one.

Note: you should prefer consumeItem as it enables better documentation generation.

consumeItem :: FromJSON v => f v

Consume a single array item.

class (Functor f, forall a. Semigroup (f a), Representational f) => JSONParser f where

Abstract class representing various parsers.

All parsers must have a Monoid instance that represents choice with failure as the identity.

Minimal complete definition

parseObject, parseDictionary, parseText, parseTuple, parseArrayWith, parseNumber, parseNull, parseBool, validateJSON

Methods

parseObject

Arguments

:: (forall objectParser. JSONObjectParser objectParser => objectParser a)

Instructions on how to parse the object. Note that the actual implementation is kept abstract: you can only use methods found in JSONObjectParser, or combinators of those methods. This ensures that we can generate the proper parser in all cases.

-> f a

parseObjectStrict :: (forall objectParser. JSONObjectParser objectParser => objectParser a) -> f a

Parse an object where you are okay if we parse strictly, IE, do not allow extra fields. This sometimes enables us to generate parsers that run faster.

parseDictionary :: (forall jsonParser. JSONParser jsonParser => jsonParser a) -> f [(Text, a)]

Parse a dictionary of key-value pairs.

parseText :: f Text

Parse a text field.

parseTextConstant :: Text -> f ()

parseTuple :: (forall arrayParser. JSONTupleParser arrayParser => arrayParser o) -> f o

Use a tuple parser to parse an array.

parseArray :: FromJSON a => f [a]

parseArrayWith :: (forall jsonParser. JSONParser jsonParser => jsonParser a) -> f [a]

parseNumber :: f Scientific

parseInteger :: f Integer

parseNull :: f ()

parseBool :: f Bool

validateJSON :: f (Either Text a) -> f a

nameParser :: Text -> f a -> f a

Give a parser a unique name. May be used for documentation.

addFormat :: Text -> f a -> f a

Add information about the format of a particular parser.

class FromJSON value where

A class to provide the canonical way to parse a JSON. This class uses finally tagless tyle to keep the instructions for parsing abstract. This allows us to automatically generate documentation, and to generate parsers that do not use intermediate structures.

This class is derivable generically, and will generate a "nice" format. In my opinion, at least.

If you want to customize this JSON, the newtype WithOptions can be helpful, as it allows you to specify options for the generic serialization. Unfortunately, due to a weird GHC quirk, you need to use it with -XStandaloneDeriving as well as -XDerivingVia . That is, you should write:

data PersonFilter = PersonFilter { filterFirstName :: Maybe Text, filterLastName :: Maybe Text }
  deriving (Show, Read, Eq, Ord, Generic)

deriving via (WithOptions '[KeepNothingFields] PersonFilter) instance (FromJSON PersonFilter)

Laws

This instance is lawless, unless ToJSON is also defined for this type. In that case, the representation parsed by FromJSON should match that of the representation serialized by ToJSON.

Minimal complete definition

Nothing

Methods

fromJSON :: JSONParser f => f value

default fromJSON :: (Generic value, GFromJSON (Rep value), Typeable value) => JSONParser f => f value

Instances

FromJSON Bool

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Bool

FromJSON Double

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Double

FromJSON Float

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Float

FromJSON Int

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Int

FromJSON Int32

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Int32

FromJSON Int64

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Int64

FromJSON Integer

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Integer

FromJSON ()

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f ()

FromJSON All

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f All

FromJSON Any

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Any

FromJSON String

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f String

FromJSON Scientific

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Scientific

FromJSON Text

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f Text

FromJSON JSONType

Defined in Jordan.Types.JSONType

Methods

fromJSON :: JSONParser f => f JSONType

FromJSON JSONArrayError

Defined in Jordan.Types.JSONError

Methods

fromJSON :: JSONParser f => f JSONArrayError

FromJSON JSONObjectError

Defined in Jordan.Types.JSONError

Methods

fromJSON :: JSONParser f => f JSONObjectError

FromJSON JSONError

Defined in Jordan.Types.JSONError

Methods

fromJSON :: JSONParser f => f JSONError

FromJSON JSONValue

Defined in Jordan.Types.JSONValue

Methods

fromJSON :: JSONParser f => f JSONValue

FromJSON a => FromJSON [a]

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f [a]

FromJSON a => FromJSON (Maybe a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Maybe a)

(Integral a, FromJSON a) => FromJSON (Ratio a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Ratio a)

FromJSON a => FromJSON (Min a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Min a)

FromJSON a => FromJSON (Max a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Max a)

FromJSON a => FromJSON (First a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (First a)

FromJSON a => FromJSON (Last a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Last a)

FromJSON a => FromJSON (First a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (First a)

FromJSON a => FromJSON (Last a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Last a)

FromJSON a => FromJSON (Dual a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Dual a)

FromJSON a => FromJSON (Sum a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Sum a)

FromJSON a => FromJSON (Product a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Product a)

FromJSON a => FromJSON (NonEmpty a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (NonEmpty a)

(FromJSON a, Ord a) => FromJSON (Set a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Set a)

(FromJSON l, FromJSON r) => FromJSON (Either l r)

Right-biased: will try to parse a Right value first.

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Either l r)

FromJSON a => FromJSON (Map Integer a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Map Integer a)

FromJSON a => FromJSON (Map Text a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (Map Text a)

(Generic a, GFromJSON (Rep a), Typeable a, SpecifiesFromJSONOptions options) => FromJSON (WithOptions options a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f => f (WithOptions options a)

FromJSON (f a) => FromJSON (Ap f a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f0 => f0 (Ap f a)

FromJSON (f a) => FromJSON (Alt f a)

Defined in Jordan.FromJSON.Class

Methods

fromJSON :: JSONParser f0 => f0 (Alt f a)

data FromJSONOptions

Constructors

FromJSONOptions

Fields

• fromJSONEncodeSums :: SumTypeEncoding
• fromJSONBaseName :: String
• convertEnum :: String -> String
• fromJSONOmitNothingFields :: Bool

Instances

Generic FromJSONOptions

Defined in Jordan.FromJSON.Class

Associated Types

type Rep FromJSONOptions :: Type -> Type

Methods

from :: FromJSONOptions -> Rep FromJSONOptions x

to :: Rep FromJSONOptions x -> FromJSONOptions

type Rep FromJSONOptions

Defined in Jordan.FromJSON.Class

type Rep FromJSONOptions = D1 ('MetaData "FromJSONOptions" "Jordan.FromJSON.Class" "jordan-0.2.0.0-inplace" 'False) (C1 ('MetaCons "FromJSONOptions" 'PrefixI 'True) ((S1 ('MetaSel ('Just "fromJSONEncodeSums") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 SumTypeEncoding) :*: S1 ('MetaSel ('Just "fromJSONBaseName") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 String)) :*: (S1 ('MetaSel ('Just "convertEnum") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 (String -> String)) :*: S1 ('MetaSel ('Just "fromJSONOmitNothingFields") 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedLazy) (Rec0 Bool))))

defaultOptions :: FromJSONOptions

class SpecifiesFromJSONOptions (a :: [*]) where

Methods

specifiedFromJSONOptions :: FromJSONOptions

Instances

SpecifiesFromJSONOptions ('[] :: [Type])

Defined in Jordan.FromJSON.Class

Methods

specifiedFromJSONOptions :: FromJSONOptions

SpecifiesFromJSONOptions xs => SpecifiesFromJSONOptions (KeepNothingFields ': xs)

Defined in Jordan.FromJSON.Class

Methods

specifiedFromJSONOptions :: FromJSONOptions

SpecifiesFromJSONOptions xs => SpecifiesFromJSONOptions (OmitNothingFields ': xs)

Defined in Jordan.FromJSON.Class

Methods

specifiedFromJSONOptions :: FromJSONOptions

addName :: String -> FromJSONOptions -> FromJSONOptions

class GFromJSON v where

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (v a)

Instances

(GFromJSON (PartOfSum l), GFromJSON (PartOfSum r)) => GFromJSON (PartOfSum (l :+: r))

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (PartOfSum (l :+: r) a)

(GFromJSON (C1 t f), Constructor t) => GFromJSON (PartOfSum (C1 t f))

When rendering a sum type, if we have a more complex value (IE, maybe this is a constructor that takes arguments), we want to use whatever sum encoding was provided in the options.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f0 => FromJSONOptions -> f0 (PartOfSum (C1 t f) a)

KnownSymbol connName => GFromJSON (PartOfSum (C1 ('MetaCons connName dontCare 'False) (U1 :: Type -> Type)))

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (PartOfSum (C1 ('MetaCons connName dontCare 'False) U1) a)

FromJSON c => GFromJSON (K1 i c :: Type -> Type)

Top-level metadata is ignored.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (K1 i c a)

(GFromJSON (PartOfSum l), GFromJSON (PartOfSum r)) => GFromJSON (l :+: r)

If we can parse both sides of a sum-type, we can parse the entire sum type.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f ((l :+: r) a)

(GFromJSON f, Datatype t) => GFromJSON (D1 t f)

Datatype metadata: we name the overall datatype with the baseName provided in the options, then serialize the inner information.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f0 => FromJSONOptions -> f0 (D1 t f a)

KnownSymbol connName => GFromJSON (C1 ('MetaCons connName dontCare 'False) (U1 :: Type -> Type))

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (C1 ('MetaCons connName dontCare 'False) U1 a)

(FromJSON inner, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) ss su dl) (Rec0 inner)))

Special-case: a one-argument constructor with no field selector gets its own parser, skipping the tuple entirely.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (C1 ('MetaCons n s 'False) (S1 ('MetaSel 'Nothing ss su dl) (Rec0 inner)) a)

(GFromJSONObject i, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'True) i)

If we have a constructor with arguments, and those arguments do have selectors (IE, this is a record), then we should parse as a record.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (C1 ('MetaCons n s 'True) i a)

(GFromJSONTuple inner, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'False) inner)

If we have a constructor with arguments, and those arguments do not have selectors (IE, this is not a record), then we should parse as a tuple.

Defined in Jordan.FromJSON.Class

Methods

gFromJSON :: JSONParser f => FromJSONOptions -> f (C1 ('MetaCons n s 'False) inner a)

class GFromJSONObject v where

Class that helps us parse JSON objects.

Methods

gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (v a)

Instances

GFromJSONObject (U1 :: Type -> Type)

Defined in Jordan.FromJSON.Class

Methods

gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (U1 a)

(GFromJSONObject lhs, GFromJSONObject rhs) => GFromJSONObject (lhs :*: rhs)

Defined in Jordan.FromJSON.Class

Methods

gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f ((lhs :*: rhs) a)

(FromJSON c, Selector t) => GFromJSONObject (S1 t (K1 v (Maybe c) :: Type -> Type))

Defined in Jordan.FromJSON.Class

Methods

gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (S1 t (K1 v (Maybe c)) a)

(FromJSON c, Selector t) => GFromJSONObject (S1 t (K1 v c :: Type -> Type))

Defined in Jordan.FromJSON.Class

Methods

gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (S1 t (K1 v c) a)

class GFromJSONTuple v where

Methods

gFromJSONTuple :: JSONTupleParser f => FromJSONOptions -> f (v a)

Instances

(GFromJSONTuple lhs, GFromJSONTuple rhs) => GFromJSONTuple (lhs :*: rhs)

Defined in Jordan.FromJSON.Class

Methods

gFromJSONTuple :: JSONTupleParser f => FromJSONOptions -> f ((lhs :*: rhs) a)

GFromJSON f => GFromJSONTuple (S1 ('MetaSel ('Nothing :: Maybe Symbol) su ss ds) f)

Defined in Jordan.FromJSON.Class

Methods

gFromJSONTuple :: JSONTupleParser f0 => FromJSONOptions -> f0 (S1 ('MetaSel 'Nothing su ss ds) f a)