5bf02dc · typeable/aeson

249-- Generic and TH encoding configuration

250--------------------------------------------------------------------------------

251

252−-- | Options that specify how to encode/decode your datatype to/from JSON.

252+-- | Options that specify how to encode\/decode your datatype to\/from JSON.

253data Options = Options

254 { fieldNameModifier :: String -> String

255 -- ^ Function applied to field names.

257 , constructorNameModifier :: String -> String

258 -- ^ Function applied to constructor names.

259 -- Handy for lower-casing constructor names for example.

260− , nullaryToString :: Bool

260+ , nullaryToString :: Bool

261− -- ^ If 'True' the constructors of a datatype, with all nullary

261+ -- ^ If 'True' the constructors of a datatype, with /all/ nullary

262 -- constructors, will be encoded to a string with the

263 -- constructor name. If 'False' the encoding will always follow

264 -- the `sumEncoding`.

265 , omitNothingFields :: Bool

266 -- ^ If 'True' record fields with a 'Nothing' value will be

267 -- omitted from the resulting object. If 'False' the resulting

268− -- object will include those fields with @null@ values.

268+ -- object will include those fields mapping to @null@.

269− , sumEncoding :: SumEncoding

269+ , sumEncoding :: SumEncoding

270 -- ^ Specifies how to encode constructors of a sum datatype.

271 }

272

273-- | Specifies how to encode constructors of a sum datatype.

274data SumEncoding =

275− TwoElemArray -- ^ A constructor will be encoded to a 2-element

276− -- array where the first element is the name of the

277− -- constructor (modified by the

278− -- 'constructorNameModifier') and the second element

279− -- the content of the constructor.

280− | ObjectWithType { typeFieldName :: String

275+ ObjectWithType { typeFieldName :: String

281 , valueFieldName :: String

276 , valueFieldName :: String

282 }

277 }

283 -- ^ A constructor will be encoded to an object with a field

278 -- ^ A constructor will be encoded to an object with a field

284 -- 'typeFieldName' which specifies the constructor name (modified

279 -- 'typeFieldName' which specifies the constructor name (modified

285− -- by the 'constructorNameModifier'). If the constructor is not a

280+ -- by the 'constructorNameModifier'). If the constructor is a

281+ -- record the encoded record fields will be unpacked into this

282+ -- object. So make sure that your record doesn't have a field with

283+ -- the same name as the 'typeFieldName'. Otherwise the type gets

284+ -- overwritten by that field. If the constructor is not a record

286− -- record the constructor content will be stored under the

285+ -- the encoded constructor content will be stored under the

287 -- 'valueFieldName' field.

286 -- 'valueFieldName' field.

288 | ObjectWithSingleField

287 | ObjectWithSingleField

289 -- ^ A constructor will be encoded to an object with a single

288 -- ^ A constructor will be encoded to an object with a single

290 -- field named after the constructor (modified by the

289 -- field named after the constructor (modified by the

291− -- 'constructorNameModifier') and the value will be the contents

290+ -- 'constructorNameModifier') which maps to the encoded contents

292 -- of the constructor.

291 -- of the constructor.

292+ | TwoElemArray

293+ -- ^ A constructor will be encoded to a 2-element array where the

294+ -- first element is the name of the constructor (modified by the

295+ -- 'constructorNameModifier') and the second element the encoded

296+ -- content of the constructor.

293

297

294-- | Default encoding 'Options':

298-- | Default encoding 'Options':

295--

299--