| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Jordan.FromJSON.Class
Description
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!
Synopsis
- class (Applicative f, Representational f) => JSONObjectParser f where
- parseFieldWith :: Text -> (forall valueParser. JSONParser valueParser => valueParser a) -> f a
- parseDescribeFieldWith :: Text -> Text -> (forall valueParser. JSONParser valueParser => valueParser a) -> f a
- parseField :: FromJSON v => Text -> f v
- parseDescribeField :: FromJSON v => Text -> Text -> f v
- parseFieldWithDefault :: Text -> (forall valueParser. JSONParser valueParser => valueParser a) -> a -> f a
- parseDescribeFieldWithDefault :: Text -> Text -> (forall valueParser. JSONParser valueParser => valueParser a) -> a -> f a
- class (Applicative f, Representational f) => JSONTupleParser f where
- consumeItemWith :: (forall valueParser. JSONParser valueParser => valueParser a) -> f a
- consumeItem :: FromJSON v => f v
- class (Functor f, forall a. Semigroup (f a), Representational f) => JSONParser f where
- parseObject :: (forall objectParser. JSONObjectParser objectParser => objectParser a) -> f a
- parseObjectStrict :: (forall objectParser. JSONObjectParser objectParser => objectParser a) -> f a
- parseDictionary :: (forall jsonParser. JSONParser jsonParser => jsonParser a) -> f [(Text, a)]
- parseText :: f Text
- parseTextConstant :: Text -> f ()
- parseTuple :: (forall arrayParser. JSONTupleParser arrayParser => arrayParser o) -> f o
- 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
- addFormat :: Text -> f a -> f a
- class FromJSON value where
- fromJSON :: JSONParser f => f value
- data FromJSONOptions = FromJSONOptions {}
- defaultOptions :: FromJSONOptions
- class SpecifiesFromJSONOptions (a :: [*]) where
- addName :: String -> FromJSONOptions -> FromJSONOptions
- class GFromJSON v where
- gFromJSON :: JSONParser f => FromJSONOptions -> f (v a)
- class GFromJSONObject v where
- gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (v a)
- class GFromJSONTuple v where
- gFromJSONTuple :: JSONTupleParser f => FromJSONOptions -> f (v a)
Documentation
class (Applicative f, Representational f) => JSONObjectParser f where Source #
A class for parsing JSON objects.
Minimal complete definition
Methods
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 Source #
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 Source #
parseDescribeField :: FromJSON v => Text -> Text -> f v Source #
parseFieldWithDefault Source #
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 Source #
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 Source #
A class for parsing JSON arrays.
Minimal complete definition
Methods
consumeItemWith :: (forall valueParser. JSONParser valueParser => valueParser a) -> f a Source #
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 Source #
Consume a single array item.
class (Functor f, forall a. Semigroup (f a), Representational f) => JSONParser f where Source #
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
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 Source #
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)] Source #
Parse a dictionary of key-value pairs.
Parse a text field.
parseTextConstant :: Text -> f () Source #
parseTuple :: (forall arrayParser. JSONTupleParser arrayParser => arrayParser o) -> f o Source #
Use a tuple parser to parse an array.
parseArray :: FromJSON a => f [a] Source #
parseArrayWith :: (forall jsonParser. JSONParser jsonParser => jsonParser a) -> f [a] Source #
parseNumber :: f Scientific Source #
parseInteger :: f Integer Source #
validateJSON :: f (Either Text a) -> f a Source #
nameParser :: Text -> f a -> f a Source #
Give a parser a unique name. May be used for documentation.
addFormat :: Text -> f a -> f a Source #
Add information about the format of a particular parser.
class FromJSON value where Source #
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
Minimal complete definition
Nothing
Methods
fromJSON :: JSONParser f => f value Source #
Instances
data FromJSONOptions Source #
Constructors
| FromJSONOptions | |
Fields | |
Instances
| Generic FromJSONOptions Source # | |
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 Source # | |
Defined in Jordan.FromJSON.Class type Rep FromJSONOptions = D1 ('MetaData "FromJSONOptions" "Jordan.FromJSON.Class" "jordan-0.2.0.0-He2CL9yJm8jJiPwP3VkPys" '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)))) | |
class SpecifiesFromJSONOptions (a :: [*]) where Source #
Methods
Instances
| SpecifiesFromJSONOptions ('[] :: [Type]) Source # | |
Defined in Jordan.FromJSON.Class Methods | |
| SpecifiesFromJSONOptions xs => SpecifiesFromJSONOptions (KeepNothingFields ': xs) Source # | |
Defined in Jordan.FromJSON.Class Methods | |
| SpecifiesFromJSONOptions xs => SpecifiesFromJSONOptions (OmitNothingFields ': xs) Source # | |
Defined in Jordan.FromJSON.Class Methods | |
addName :: String -> FromJSONOptions -> FromJSONOptions Source #
class GFromJSON v where Source #
Methods
gFromJSON :: JSONParser f => FromJSONOptions -> f (v a) Source #
Instances
| (GFromJSON (PartOfSum l), GFromJSON (PartOfSum r)) => GFromJSON (PartOfSum (l :+: r)) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSON :: JSONParser f => FromJSONOptions -> f (PartOfSum (l :+: r) a) Source # | |
| (GFromJSON (C1 t f), Constructor t) => GFromJSON (PartOfSum (C1 t f)) Source # | 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) Source # | |
| KnownSymbol connName => GFromJSON (PartOfSum (C1 ('MetaCons connName dontCare 'False) (U1 :: Type -> Type))) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSON :: JSONParser f => FromJSONOptions -> f (PartOfSum (C1 ('MetaCons connName dontCare 'False) U1) a) Source # | |
| FromJSON c => GFromJSON (K1 i c :: Type -> Type) Source # | Top-level metadata is ignored. |
Defined in Jordan.FromJSON.Class Methods gFromJSON :: JSONParser f => FromJSONOptions -> f (K1 i c a) Source # | |
| (GFromJSON (PartOfSum l), GFromJSON (PartOfSum r)) => GFromJSON (l :+: r) Source # | 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) Source # | |
| (GFromJSON f, Datatype t) => GFromJSON (D1 t f) Source # | 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) Source # | |
| KnownSymbol connName => GFromJSON (C1 ('MetaCons connName dontCare 'False) (U1 :: Type -> Type)) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSON :: JSONParser f => FromJSONOptions -> f (C1 ('MetaCons connName dontCare 'False) U1 a) Source # | |
| (FromJSON inner, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) ss su dl) (Rec0 inner))) Source # | Special-case: a one-argument constructor with no field selector gets its own parser, skipping the tuple entirely. |
Defined in Jordan.FromJSON.Class | |
| (GFromJSONObject i, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'True) i) Source # | 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) Source # | |
| (GFromJSONTuple inner, KnownSymbol n) => GFromJSON (C1 ('MetaCons n s 'False) inner) Source # | 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) Source # | |
class GFromJSONObject v where Source #
Class that helps us parse JSON objects.
Methods
gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (v a) Source #
Instances
| GFromJSONObject (U1 :: Type -> Type) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (U1 a) Source # | |
| (GFromJSONObject lhs, GFromJSONObject rhs) => GFromJSONObject (lhs :*: rhs) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f ((lhs :*: rhs) a) Source # | |
| (FromJSON c, Selector t) => GFromJSONObject (S1 t (K1 v (Maybe c) :: Type -> Type)) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (S1 t (K1 v (Maybe c)) a) Source # | |
| (FromJSON c, Selector t) => GFromJSONObject (S1 t (K1 v c :: Type -> Type)) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONObject :: JSONObjectParser f => FromJSONOptions -> f (S1 t (K1 v c) a) Source # | |
class GFromJSONTuple v where Source #
Methods
gFromJSONTuple :: JSONTupleParser f => FromJSONOptions -> f (v a) Source #
Instances
| (GFromJSONTuple lhs, GFromJSONTuple rhs) => GFromJSONTuple (lhs :*: rhs) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONTuple :: JSONTupleParser f => FromJSONOptions -> f ((lhs :*: rhs) a) Source # | |
| GFromJSON f => GFromJSONTuple (S1 ('MetaSel ('Nothing :: Maybe Symbol) su ss ds) f) Source # | |
Defined in Jordan.FromJSON.Class Methods gFromJSONTuple :: JSONTupleParser f0 => FromJSONOptions -> f0 (S1 ('MetaSel 'Nothing su ss ds) f a) Source # | |