@@ -5,16 +5,19 @@
55{-# LANGUAGE FlexibleInstances #-}
66{-# LANGUAGE GADTs #-}
77{-# LANGUAGE MultiParamTypeClasses #-}
8−{-# LANGUAGE NoImplicitPrelude #-}
8+{-# LANGUAGE NamedFieldPuns #-}
99{-# LANGUAGE OverloadedStrings #-}
10−{-# LANGUAGE PolyKinds #-}
1110{-# LANGUAGE RecordWildCards #-}
1211{-# LANGUAGE ScopedTypeVariables #-}
1312{-# LANGUAGE TypeOperators #-}
14−{-# LANGUAGE TupleSections #-}
13+{-# LANGUAGE TypeSynonymInstances #-}
1514{-# LANGUAGE UndecidableInstances #-}
1615{-# LANGUAGE ViewPatterns #-}
1716
17+#if __GLASGOW_HASKELL__ >= 706
18+{-# LANGUAGE PolyKinds #-}
19+#endif
20+
1821#include "incoherent-compat.h"
1922#include "overlapping-compat.h"
2023
@@ -42,9 +45,6 @@ module Data.Aeson.Types.FromJSON
4245 , coerceFromJSONKeyFunction
4346 , mapFromJSONKeyFunction
4447
45− , GFromJSONKey()
46− , genericFromJSONKey
47−
4848 -- * List functions
4949 , listParser
5050
@@ -60,14 +60,12 @@ module Data.Aeson.Types.FromJSON
6060 , fromJSON
6161 , ifromJSON
6262 , typeMismatch
63− , unexpected
6463 , parseField
6564 , parseFieldMaybe
6665 , parseFieldMaybe'
6766 , explicitParseField
6867 , explicitParseFieldMaybe
6968 , explicitParseFieldMaybe'
70− , parseIndexedJSON
7169 -- ** Operators
7270 , (.:)
7371 , (.:?)
@@ -78,16 +76,17 @@ module Data.Aeson.Types.FromJSON
7876 , parseOptionalFieldWith
7977 ) where
8078
79+import Prelude ()
8180import Prelude.Compat
8281
83−import Control.Applicative ((<|>), Const(..), liftA2)
84−import Control.Monad (zipWithM)
82+import Control.Applicative ((<|>), Const(..))
83+import Control.Monad ((<=<), zipWithM)
8584import Data.Aeson.Internal.Functions (mapKey)
8685import Data.Aeson.Parser.Internal (eitherDecodeWith, jsonEOF)
8786import Data.Aeson.Types.Generic
8887import Data.Aeson.Types.Internal
8988import Data.Bits (unsafeShiftR)
90−import Data.Fixed (Fixed, HasResolution (resolution), Nano)
89+import Data.Fixed (Fixed, HasResolution)
9190import Data.Functor.Compose (Compose(..))
9291import Data.Functor.Identity (Identity(..))
9392import Data.Functor.Product (Product(..))
@@ -103,14 +102,11 @@ import Data.Scientific (Scientific, base10Exponent)
103102import Data.Tagged (Tagged(..))
104103import Data.Text (Text, pack, unpack)
105104import Data.Time (Day, DiffTime, LocalTime, NominalDiffTime, TimeOfDay, UTCTime, ZonedTime)
106−import Data.Time.Calendar.Compat (CalendarDiffDays (..), DayOfWeek (..))
107−import Data.Time.LocalTime.Compat (CalendarDiffTime (..))
108−import Data.Time.Clock.System.Compat (SystemTime (..))
109−import Data.Time.Format.Compat (parseTimeM, defaultTimeLocale)
105+import Data.Time.Format (parseTime)
106+import Data.Time.Locale.Compat (defaultTimeLocale)
110107import Data.Traversable as Tr (sequence)
111108import Data.Vector (Vector)
112109import Data.Version (Version, parseVersion)
113−import Data.Void (Void)
114110import Data.Word (Word16, Word32, Word64, Word8)
115111import Foreign.Storable (Storable)
116112import Foreign.C.Types (CTime (..))
@@ -118,9 +114,9 @@ import GHC.Generics
118114import Numeric.Natural (Natural)
119115import Text.ParserCombinators.ReadP (readP_to_S)
120116import Unsafe.Coerce (unsafeCoerce)
117+import qualified Data.Aeson.Compat as Compat
121118import qualified Data.Aeson.Parser.Time as Time
122119import qualified Data.Attoparsec.ByteString.Char8 as A (endOfInput, parseOnly, scientific)
123−import qualified Data.ByteString.Lazy as L
124120import qualified Data.DList as DList
125121import qualified Data.HashMap.Strict as H
126122import qualified Data.HashSet as HashSet
@@ -143,20 +139,18 @@ import qualified Data.Vector.Primitive as VP
143139import qualified Data.Vector.Storable as VS
144140import qualified Data.Vector.Unboxed as VU
145141
146−import qualified GHC.Exts as Exts
147−import qualified Data.Primitive.Array as PM
148−import qualified Data.Primitive.SmallArray as PM
149−import qualified Data.Primitive.Types as PM
150−
151−#if MIN_VERSION_primitive(0,6,4)
152−#if !MIN_VERSION_primitive(0,7,0)
153−import qualified Data.Primitive.UnliftedArray as PM
142+#ifndef HAS_COERCIBLE
143+#define HAS_COERCIBLE (__GLASGOW_HASKELL__ >= 707)
154144#endif
155−import qualified Data.Primitive.PrimArray as PM
156−#endif
157−
158145
146+#if HAS_COERCIBLE
159147import Data.Coerce (Coercible, coerce)
148+coerce' :: Coercible a b => a -> b
149+coerce' = coerce
150+#else
151+coerce' :: a -> b
152+coerce' = unsafeCoerce
153+#endif
160154
161155parseIndexedJSON :: (Value -> Parser a) -> Int -> Value -> Parser a
162156parseIndexedJSON p idx value = p value <?> Index idx
@@ -165,7 +159,7 @@ parseIndexedJSON p idx value = p value <?> Index idx
165159parseIndexedJSONPair :: (Value -> Parser a) -> (Value -> Parser b) -> Int -> Value -> Parser (a, b)
166160parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
167161 where
168− p = withArray "(k, v)" $ \ab ->
162+ p = withArray "(k,v)" $ \ab ->
169163 let n = V.length ab
170164 in if n == 2
171165 then (,) <$> parseJSONElemAtIndex keyParser 0 ab
@@ -178,33 +172,33 @@ parseJSONElemAtIndex :: (Value -> Parser a) -> Int -> V.Vector Value -> Parser a
178172parseJSONElemAtIndex p idx ary = p (V.unsafeIndex ary idx) <?> Index idx
179173
180174parseRealFloat :: RealFloat a => String -> Value -> Parser a
181−parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
182−parseRealFloat _ Null = pure (0/0)
183−parseRealFloat name v = prependContext name (unexpected v)
175+parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
176+parseRealFloat _ Null = pure (0/0)
177+parseRealFloat expected v = typeMismatch expected v
184178{-# INLINE parseRealFloat #-}
185179
186−parseIntegralFromScientific :: forall a. Integral a => Scientific -> Parser a
187−parseIntegralFromScientific s =
180+parseIntegralFromScientific :: forall a. Integral a => String -> Scientific -> Parser a
181+parseIntegralFromScientific expected s =
188182 case Scientific.floatingOrInteger s :: Either Double a of
189183 Right x -> pure x
190− Left _ -> fail $ "unexpected floating number " ++ show s
184+ Left _ -> fail $ "expected " ++ expected ++ ", encountered floating number " ++ show s
191185{-# INLINE parseIntegralFromScientific #-}
192186
193187parseIntegral :: Integral a => String -> Value -> Parser a
194−parseIntegral name =
195− prependContext name . withBoundedScientific' parseIntegralFromScientific
188+parseIntegral expected =
189+ withBoundedScientific expected $ parseIntegralFromScientific expected
196190{-# INLINE parseIntegral #-}
197191
198−parseBoundedIntegralFromScientific :: (Bounded a, Integral a) => Scientific -> Parser a
199−parseBoundedIntegralFromScientific s = maybe
200− (fail $ "value is either floating or will cause over or underflow " ++ show s)
192+parseBoundedIntegralFromScientific :: (Bounded a, Integral a) => String -> Scientific -> Parser a
193+parseBoundedIntegralFromScientific expected s = maybe
194+ (fail $ expected ++ " is either floating or will cause over or underflow: " ++ show s)
201195 pure
202196 (Scientific.toBoundedInteger s)
203197{-# INLINE parseBoundedIntegralFromScientific #-}
204198
205199parseBoundedIntegral :: (Bounded a, Integral a) => String -> Value -> Parser a
206−parseBoundedIntegral name =
207− prependContext name . withScientific' parseBoundedIntegralFromScientific
200+parseBoundedIntegral expected =
201+ withScientific expected $ parseBoundedIntegralFromScientific expected
208202{-# INLINE parseBoundedIntegral #-}
209203
210204parseScientificText :: Text -> Parser Scientific
@@ -214,20 +208,18 @@ parseScientificText
214208 . T.encodeUtf8
215209
216210parseIntegralText :: Integral a => String -> Text -> Parser a
217−parseIntegralText name t =
218− prependContext name $
219− parseScientificText t
220− >>= rejectLargeExponent
221− >>= parseIntegralFromScientific
211+parseIntegralText expected t
212+ = parseScientificText t
213+ >>= rejectLargeExponent
214+ >>= parseIntegralFromScientific expected
222215 where
223216 rejectLargeExponent :: Scientific -> Parser Scientific
224− rejectLargeExponent s = withBoundedScientific' pure (Number s)
217+ rejectLargeExponent s = withBoundedScientific expected pure (Number s)
225218{-# INLINE parseIntegralText #-}
226219
227220parseBoundedIntegralText :: (Bounded a, Integral a) => String -> Text -> Parser a
228−parseBoundedIntegralText name t =
229− prependContext name $
230− parseScientificText t >>= parseBoundedIntegralFromScientific
221+parseBoundedIntegralText expected t =
222+ parseScientificText t >>= parseBoundedIntegralFromScientific expected
231223
232224parseOptionalFieldWith :: (Value -> Parser (Maybe a))
233225 -> Object -> Text -> Parser (Maybe a)
@@ -287,21 +279,14 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
287279--
288280-- The basic ways to signal a failed conversion are as follows:
289281--
290−-- * 'fail' yields a custom error message: it is the recommended way of
291−-- reporting a failure;
282+-- * 'empty' and 'mzero' work, but are terse and uninformative;
292283--
293−-- * 'Control.Applicative.empty' (or 'Control.Monad.mzero') is uninformative:
294−-- use it when the error is meant to be caught by some @('<|>')@;
284+-- * 'fail' yields a custom error message;
295285--
296−-- * 'typeMismatch' can be used to report a failure when the encountered value
297−-- is not of the expected JSON type; 'unexpected' is an appropriate alternative
298−-- when more than one type may be expected, or to keep the expected type
299−-- implicit.
286+-- * 'typeMismatch' produces an informative message for cases when the
287+-- value encountered is not of the expected type.
300288--
301−-- 'prependFailure' (or 'modifyFailure') add more information to a parser's
302−-- error messages.
303−--
304−-- An example type and instance using 'typeMismatch' and 'prependFailure':
289+-- An example type and instance using 'typeMismatch':
305290--
306291-- @
307292-- \-- Allow ourselves to write 'Text' literals.
@@ -315,15 +300,13 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
315300-- '<*>' v '.:' \"y\"
316301--
317302-- \-- We do not expect a non-'Object' value here.
318−-- \-- We could use 'Control.Applicative.empty' to fail, but 'typeMismatch'
303+-- \-- We could use 'mzero' to fail, but 'typeMismatch'
319304-- \-- gives a much more informative error message.
320−-- 'parseJSON' invalid =
321−-- 'prependFailure' "parsing Coord failed, "
322−-- ('typeMismatch' \"Object\" invalid)
305+-- 'parseJSON' invalid = 'typeMismatch' \"Coord\" invalid
323306-- @
324307--
325308-- For this common case of only being concerned with a single
326−-- type of JSON value, the functions 'withObject', 'withScientific', etc.
309+-- type of JSON value, the functions 'withObject', 'withNumber', etc.
327310-- are provided. Their use is to be preferred when possible, since
328311-- they are more terse. Using 'withObject', we can rewrite the above instance
329312-- (assuming the same language extension and data type) as:
@@ -362,7 +345,7 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
362345-- @
363346--
364347-- The default implementation will be equivalent to
365−-- @parseJSON = 'genericParseJSON' 'defaultOptions'@; if you need different
348+-- @parseJSON = 'genericParseJSON' 'defaultOptions'@; If you need different
366349-- options, you can customize the generic decoding by defining:
367350--
368351-- @
@@ -380,11 +363,13 @@ class FromJSON a where
380363 parseJSON = genericParseJSON defaultOptions
381364
382365 parseJSONList :: Value -> Parser [a]
383− parseJSONList = withArray "[]" $ \a ->
384− zipWithM (parseIndexedJSON parseJSON) [0..]
366+ parseJSONList (Array a)
367+ = zipWithM (parseIndexedJSON parseJSON) [0..]
385368 . V.toList
386369 $ a
387370
371+ parseJSONList v = typeMismatch "[a]" v
372+
388373-------------------------------------------------------------------------------
389374-- Classes and types for map keys
390375-------------------------------------------------------------------------------
@@ -396,16 +381,6 @@ class FromJSON a where
396381-- > newtype SomeId = SomeId { getSomeId :: Text }
397382-- > deriving (Eq,Ord,Hashable,FromJSONKey)
398383--
399−-- If you have a sum of nullary constructors, you may use the generic
400−-- implementation:
401−--
402−-- @
403−-- data Color = Red | Green | Blue
404−-- deriving Generic
405−--
406−-- instance 'FromJSONKey' Color where
407−-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
408−-- @
409384class FromJSONKey a where
410385 -- | Strategy for parsing the key of a map-like container.
411386 fromJSONKey :: FromJSONKeyFunction a
@@ -428,7 +403,11 @@ class FromJSONKey a where
428403-- At the moment this type is intentionally not exported. 'FromJSONKeyFunction'
429404-- can be inspected, but cannot be constructed.
430405data CoerceText a where
406+#if HAS_COERCIBLE
431407 CoerceText :: Coercible Text a => CoerceText a
408+#else
409+ CoerceText :: CoerceText a
410+#endif
432411
433412-- | This type is related to 'ToJSONKeyFunction'. If 'FromJSONKeyValue' is used in the
434413-- 'FromJSONKey' instance, then 'ToJSONKeyValue' should be used in the 'ToJSONKey'
@@ -448,7 +427,7 @@ data FromJSONKeyFunction a
448427
449428-- | Only law abiding up to interpretation
450429instance Functor FromJSONKeyFunction where
451− fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce)
430+ fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce')
452431 fmap h (FromJSONKeyText f) = FromJSONKeyText (h . f)
453432 fmap h (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap h . f)
454433 fmap h (FromJSONKeyValue f) = FromJSONKeyValue (fmap h . f)
@@ -462,7 +441,9 @@ instance Functor FromJSONKeyFunction where
462441--
463442-- On pre GHC 7.8 this is unconstrainted function.
464443fromJSONKeyCoerce ::
444+#if HAS_COERCIBLE
465445 Coercible Text a =>
446+#endif
466447 FromJSONKeyFunction a
467448fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
468449
@@ -470,91 +451,60 @@ fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
470451--
471452-- See note on 'fromJSONKeyCoerce'.
472453coerceFromJSONKeyFunction ::
454+#if HAS_COERCIBLE
473455 Coercible a b =>
456+#endif
474457 FromJSONKeyFunction a -> FromJSONKeyFunction b
458+#if HAS_COERCIBLE
475459coerceFromJSONKeyFunction = coerce
460+#else
461+coerceFromJSONKeyFunction (FromJSONKeyCoerce CoerceText) = FromJSONKeyCoerce CoerceText
462+coerceFromJSONKeyFunction (FromJSONKeyText f) = FromJSONKeyText (coerce' . f)
463+coerceFromJSONKeyFunction (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap coerce' . f)
464+coerceFromJSONKeyFunction (FromJSONKeyValue f) = FromJSONKeyValue (fmap coerce' . f)
465+#endif
476466
477467{-# RULES
478468 "FromJSONKeyCoerce: fmap id" forall (x :: FromJSONKeyFunction a).
479469 fmap id x = x
480470 #-}
471+#if HAS_COERCIBLE
481472{-# RULES
482473 "FromJSONKeyCoerce: fmap coerce" forall x .
483474 fmap coerce x = coerceFromJSONKeyFunction x
484475 #-}
476+#endif
485477
486478-- | Same as 'fmap'. Provided for the consistency with 'ToJSONKeyFunction'.
487479mapFromJSONKeyFunction :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b
488480mapFromJSONKeyFunction = fmap
489481
490−-- | 'fromJSONKey' for 'Generic' types.
491−-- These types must be sums of nullary constructors, whose names will be used
492−-- as keys for JSON objects.
493−--
494−-- See also 'genericToJSONKey'.
495−--
496−-- === __Example__
497−--
498−-- @
499−-- data Color = Red | Green | Blue
500−-- deriving 'Generic'
501−--
502−-- instance 'FromJSONKey' Color where
503−-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
504−-- @
505−genericFromJSONKey :: forall a. (Generic a, GFromJSONKey (Rep a))
506− => JSONKeyOptions
507− -> FromJSONKeyFunction a
508−genericFromJSONKey opts = FromJSONKeyTextParser $ \t ->
509− case parseSumFromString (keyModifier opts) t of
510− Nothing -> fail $
511− "invalid key " ++ show t ++ ", expected one of " ++ show cnames
512− Just k -> pure (to k)
513− where
514− cnames = unTagged2 (constructorTags (keyModifier opts) :: Tagged2 (Rep a) [String])
515−
516−class (ConstructorNames f, SumFromString f) => GFromJSONKey f where
517−instance (ConstructorNames f, SumFromString f) => GFromJSONKey f where
518−
519482-------------------------------------------------------------------------------
520483-- Functions needed for documentation
521484-------------------------------------------------------------------------------
522485
523486-- | Fail parsing due to a type mismatch, with a descriptive message.
524487--
525−-- The following wrappers should generally be prefered:
526−-- 'withObject', 'withArray', 'withText', 'withBool'.
527−--
528−-- ==== Error message example
488+-- Example usage:
529489--
530−-- > typeMismatch "Object" (String "oops")
531−-- > -- Error: "expected Object, but encountered String"
532−typeMismatch :: String -- ^ The name of the JSON type being parsed
533− -- (@\"Object\"@, @\"Array\"@, @\"String\"@, @\"Number\"@,
534− -- @\"Boolean\"@, or @\"Null\"@).
490+-- @
491+-- instance FromJSON Coord where
492+-- parseJSON ('Object' v) = {- type matches, life is good -}
493+-- parseJSON wat = 'typeMismatch' \"Coord\" wat
494+-- @
495+typeMismatch :: String -- ^ The name of the type you are trying to parse.
535496 -> Value -- ^ The actual value encountered.
536497 -> Parser a
537498typeMismatch expected actual =
538− fail $ "expected " ++ expected ++ ", but encountered " ++ typeOf actual
539−
540−-- | Fail parsing due to a type mismatch, when the expected types are implicit.
541−--
542−-- ==== Error message example
543−--
544−-- > unexpected (String "oops")
545−-- > -- Error: "unexpected String"
546−unexpected :: Value -> Parser a
547−unexpected actual = fail $ "unexpected " ++ typeOf actual
548−
549−-- | JSON type of a value, name of the head constructor.
550−typeOf :: Value -> String
551−typeOf v = case v of
552− Object _ -> "Object"
553− Array _ -> "Array"
554− String _ -> "String"
555− Number _ -> "Number"
556− Bool _ -> "Boolean"
557− Null -> "Null"
499+ fail $ "expected " ++ expected ++ ", encountered " ++ name
500+ where
501+ name = case actual of
502+ Object _ -> "Object"
503+ Array _ -> "Array"
504+ String _ -> "String"
505+ Number _ -> "Number"
506+ Bool _ -> "Boolean"
507+ Null -> "Null"
558508
559509-------------------------------------------------------------------------------
560510-- Lifings of FromJSON and ToJSON to unary and binary type constructors
@@ -635,8 +585,9 @@ class FromJSON2 f where
635585 -> (Value -> Parser b)
636586 -> (Value -> Parser [b])
637587 -> Value -> Parser [f a b]
638− liftParseJSONList2 fa ga fb gb = withArray "[]" $ \vals ->
639− fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
588+ liftParseJSONList2 fa ga fb gb v = case v of
589+ Array vals -> fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
590+ _ -> typeMismatch "[a]" v
640591
641592-- | Lift the standard 'parseJSON' function through the type constructor.
642593parseJSON2 :: (FromJSON2 f, FromJSON a, FromJSON b) => Value -> Parser (f a b)
@@ -650,7 +601,7 @@ parseJSON2 = liftParseJSON2 parseJSON parseJSONList parseJSON parseJSONList
650601-- | Helper function to use with 'liftParseJSON'. See 'Data.Aeson.ToJSON.listEncoding'.
651602listParser :: (Value -> Parser a) -> Value -> Parser [a]
652603listParser f (Array xs) = fmap V.toList (V.mapM f xs)
653−listParser _ v = typeMismatch "Array" v
604+listParser _ v = typeMismatch "[a]" v
654605{-# INLINE listParser #-}
655606
656607-------------------------------------------------------------------------------
@@ -668,137 +619,69 @@ instance (FromJSON a) => FromJSON [a] where
668619-- Functions
669620-------------------------------------------------------------------------------
670621
671−-- | Add context to a failure message, indicating the name of the structure
672−-- being parsed.
673−--
674−-- > prependContext "MyType" (fail "[error message]")
675−-- > -- Error: "parsing MyType failed, [error message]"
676−prependContext :: String -> Parser a -> Parser a
677−prependContext name = prependFailure ("parsing " ++ name ++ " failed, ")
678−
679−-- | @'withObject' name f value@ applies @f@ to the 'Object' when @value@
680−-- is an 'Data.Aeson.Object' and fails otherwise.
681−--
682−-- ==== Error message example
683−--
684−-- > withObject "MyType" f (String "oops")
685−-- > -- Error: "parsing MyType failed, expected Object, but encountered String"
622+-- | @'withObject' expected f value@ applies @f@ to the 'Object' when @value@
623+-- is an 'Object' and fails using @'typeMismatch' expected@ otherwise.
686624withObject :: String -> (Object -> Parser a) -> Value -> Parser a
687−withObject _ f (Object obj) = f obj
688−withObject name _ v = prependContext name (typeMismatch "Object" v)
625+withObject _ f (Object obj) = f obj
626+withObject expected _ v = typeMismatch expected v
689627{-# INLINE withObject #-}
690628
691−-- | @'withText' name f value@ applies @f@ to the 'Text' when @value@ is a
692−-- 'Data.Aeson.String' and fails otherwise.
693−--
694−-- ==== Error message example
695−--
696−-- > withText "MyType" f Null
697−-- > -- Error: "parsing MyType failed, expected String, but encountered Null"
629+-- | @'withText' expected f value@ applies @f@ to the 'Text' when @value@ is a
630+-- 'String' and fails using @'typeMismatch' expected@ otherwise.
698631withText :: String -> (Text -> Parser a) -> Value -> Parser a
699−withText _ f (String txt) = f txt
700−withText name _ v = prependContext name (typeMismatch "String" v)
632+withText _ f (String txt) = f txt
633+withText expected _ v = typeMismatch expected v
701634{-# INLINE withText #-}
702635
703636-- | @'withArray' expected f value@ applies @f@ to the 'Array' when @value@ is
704−-- an 'Data.Aeson.Array' and fails otherwise.
705−--
706−-- ==== Error message example
707−--
708−-- > withArray "MyType" f (String "oops")
709−-- > -- Error: "parsing MyType failed, expected Array, but encountered String"
637+-- an 'Array' and fails using @'typeMismatch' expected@ otherwise.
710638withArray :: String -> (Array -> Parser a) -> Value -> Parser a
711−withArray _ f (Array arr) = f arr
712−withArray name _ v = prependContext name (typeMismatch "Array" v)
639+withArray _ f (Array arr) = f arr
640+withArray expected _ v = typeMismatch expected v
713641{-# INLINE withArray #-}
714642
715−-- | @'withScientific' name f value@ applies @f@ to the 'Scientific' number
716−-- when @value@ is a 'Data.Aeson.Number' and fails using 'typeMismatch'
643+-- | @'withScientific' expected f value@ applies @f@ to the 'Scientific' number
644+-- when @value@ is a 'Number' and fails using @'typeMismatch' expected@
717645-- otherwise.
718−--
646+-- .
719647-- /Warning/: If you are converting from a scientific to an unbounded
720648-- type such as 'Integer' you may want to add a restriction on the
721649-- size of the exponent (see 'withBoundedScientific') to prevent
722650-- malicious input from filling up the memory of the target system.
723−--
724−-- ==== Error message example
725−--
726−-- > withScientific "MyType" f (String "oops")
727−-- > -- Error: "parsing MyType failed, expected Number, but encountered String"
728651withScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
729−withScientific _ f (Number scientific) = f scientific
730−withScientific name _ v = prependContext name (typeMismatch "Number" v)
652+withScientific _ f (Number scientific) = f scientific
653+withScientific expected _ v = typeMismatch expected v
731654{-# INLINE withScientific #-}
732655
733−-- | A variant of 'withScientific' which doesn't use 'prependContext', so that
734−-- such context can be added separately in a way that also applies when the
735−-- continuation @f :: Scientific -> Parser a@ fails.
736−--
737−-- /Warning/: If you are converting from a scientific to an unbounded
738−-- type such as 'Integer' you may want to add a restriction on the
739−-- size of the exponent (see 'withBoundedScientific') to prevent
740−-- malicious input from filling up the memory of the target system.
741−--
742−-- ==== Error message examples
656+-- | @'withBoundedScientific' expected f value@ applies @f@ to the 'Scientific' number
657+-- when @value@ is a 'Number' and fails using @'typeMismatch' expected@
658+-- otherwise.
743659--
744−-- > withScientific' f (String "oops")
745−-- > -- Error: "unexpected String"
746−-- >
747−-- > prependContext "MyType" (withScientific' f (String "oops"))
748−-- > -- Error: "parsing MyType failed, unexpected String"
749−withScientific' :: (Scientific -> Parser a) -> Value -> Parser a
750−withScientific' f v = case v of
751− Number n -> f n
752− _ -> typeMismatch "Number" v
753−{-# INLINE withScientific' #-}
754−
755−-- | @'withBoundedScientific' name f value@ applies @f@ to the 'Scientific' number
756−-- when @value@ is a 'Number' with exponent less than or equal to 1024.
660+-- The conversion will also fail wyth a @'typeMismatch' if the
661+-- 'Scientific' exponent is larger than 1024.
757662withBoundedScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
758−withBoundedScientific name f v = withBoundedScientific_ (prependContext name) f v
759−{-# INLINE withBoundedScientific #-}
760−
761−-- | A variant of 'withBoundedScientific' which doesn't use 'prependContext',
762−-- so that such context can be added separately in a way that also applies
763−-- when the continuation @f :: Scientific -> Parser a@ fails.
764−withBoundedScientific' :: (Scientific -> Parser a) -> Value -> Parser a
765−withBoundedScientific' f v = withBoundedScientific_ id f v
766−{-# INLINE withBoundedScientific' #-}
767−
768−-- | A variant of 'withBoundedScientific_' parameterized by a function to apply
769−-- to the 'Parser' in case of failure.
770−withBoundedScientific_ :: (Parser a -> Parser a) -> (Scientific -> Parser a) -> Value -> Parser a
771−withBoundedScientific_ whenFail f (Number scientific) =
772− if exp10 > 1024
773− then whenFail (fail msg)
663+withBoundedScientific _ f v@(Number scientific) =
664+ if base10Exponent scientific > 1024
665+ then typeMismatch "a number with exponent <= 1024" v
774666 else f scientific
775− where
776− exp10 = base10Exponent scientific
777− msg = "found a number with exponent " ++ show exp10 ++ ", but it must not be greater than 1024"
778−withBoundedScientific_ whenFail _ v =
779− whenFail (typeMismatch "Number" v)
780−{-# INLINE withBoundedScientific_ #-}
667+withBoundedScientific expected _ v = typeMismatch expected v
668+{-# INLINE withBoundedScientific #-}
781669
782670-- | @'withBool' expected f value@ applies @f@ to the 'Bool' when @value@ is a
783−-- 'Boolean' and fails otherwise.
784−--
785−-- ==== Error message example
786−--
787−-- > withBool "MyType" f (String "oops")
788−-- > -- Error: "parsing MyType failed, expected Boolean, but encountered String"
671+-- 'Bool' and fails using @'typeMismatch' expected@ otherwise.
789672withBool :: String -> (Bool -> Parser a) -> Value -> Parser a
790−withBool _ f (Bool arr) = f arr
791−withBool name _ v = prependContext name (typeMismatch "Boolean" v)
673+withBool _ f (Bool arr) = f arr
674+withBool expected _ v = typeMismatch expected v
792675{-# INLINE withBool #-}
793676
794677-- | Decode a nested JSON-encoded string.
795678withEmbeddedJSON :: String -> (Value -> Parser a) -> Value -> Parser a
796679withEmbeddedJSON _ innerParser (String txt) =
797− either fail innerParser $ eitherDecode (L.fromStrict $ T.encodeUtf8 txt)
680+ either fail innerParser $ eitherDecode (Compat.fromStrict $ T.encodeUtf8 txt)
798681 where
799682 eitherDecode = eitherFormatError . eitherDecodeWith jsonEOF ifromJSON
800683 eitherFormatError = either (Left . uncurry formatError) Right
801−withEmbeddedJSON name _ v = prependContext name (typeMismatch "String" v)
684+withEmbeddedJSON name _ v = typeMismatch name v
802685{-# INLINE withEmbeddedJSON #-}
803686
804687-- | Convert a value from JSON, failing if the types do not match.
@@ -863,7 +746,7 @@ parseFieldMaybe' = (.:!)
863746-- E.g. @'explicitParseField' 'parseJSON1' :: ('FromJSON1' f, 'FromJSON' a) -> 'Object' -> 'Text' -> 'Parser' (f a)@
864747explicitParseField :: (Value -> Parser a) -> Object -> Text -> Parser a
865748explicitParseField p obj key = case H.lookup key obj of
866− Nothing -> fail $ "key " ++ show key ++ " not found"
749+ Nothing -> fail $ "key " ++ show key ++ " not present"
867750 Just v -> p v <?> Key key
868751{-# INLINE explicitParseField #-}
869752
@@ -903,47 +786,11 @@ pmval .!= val = fromMaybe val <$> pmval
903786-- Generic parseJSON
904787-------------------------------------------------------------------------------
905788
906−instance GFromJSON arity V1 where
907− -- Whereof we cannot format, thereof we cannot parse:
908− gParseJSON _ _ _ = fail "Attempted to parse empty type"
909−
910−
911789instance OVERLAPPABLE_ (GFromJSON arity a) => GFromJSON arity (M1 i c a) where
912790 -- Meta-information, which is not handled elsewhere, is just added to the
913791 -- parsed value:
914792 gParseJSON opts fargs = fmap M1 . gParseJSON opts fargs
915793
916−-- Information for error messages
917−
918−type TypeName = String
919−type ConName = String
920−
921−-- | Add the name of the type being parsed to a parser's error messages.
922−contextType :: TypeName -> Parser a -> Parser a
923−contextType = prependContext
924−
925−-- | Add the tagKey that will be looked up while building an ADT
926−-- | Produce the error equivalent to
927−-- | Left "Error in $: parsing T failed, expected an object with keys "tag" and
928−-- | "contents", where "tag" i-- |s associated to one of ["Foo", "Bar"],
929−-- | The parser returned error was: could not find key "tag"
930−contextTag :: Text -> [String] -> Parser a -> Parser a
931−contextTag tagKey cnames = prependFailure
932− ("expected Object with key \"" ++ unpack tagKey ++ "\"" ++
933− " containing one of " ++ show cnames ++ ", ")
934−
935−-- | Add the name of the constructor being parsed to a parser's error messages.
936−contextCons :: ConName -> TypeName -> Parser a -> Parser a
937−contextCons cname tname = prependContext (showCons cname tname)
938−
939−-- | Render a constructor as @\"MyType(MyConstructor)\"@.
940−showCons :: ConName -> TypeName -> String
941−showCons cname tname = tname ++ "(" ++ cname ++ ")"
942−
943−--------------------------------------------------------------------------------
944−
945−-- Parsing single fields
946−
947794instance (FromJSON a) => GFromJSON arity (K1 i a) where
948795 -- Constant values are decoded using their FromJSON instance:
949796 gParseJSON _opts _ = fmap K1 . parseJSON
@@ -958,499 +805,342 @@ instance (FromJSON1 f) => GFromJSON One (Rec1 f) where
958805 -- FromJSON1 instance:
959806 gParseJSON _opts (From1Args pj pjl) = fmap Rec1 . liftParseJSON pj pjl
960807
961−instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
962− -- If an occurrence of the last type parameter is nested inside two
963− -- composed types, it is decoded by using the outermost type's FromJSON1
964− -- instance to generically decode the innermost type:
965− gParseJSON opts fargs =
966− let gpj = gParseJSON opts fargs in
967− fmap Comp1 . liftParseJSON gpj (listParser gpj)
968−
969−--------------------------------------------------------------------------------
970−
971−instance (GFromJSON' arity a, Datatype d) => GFromJSON arity (D1 d a) where
972− -- Meta-information, which is not handled elsewhere, is just added to the
973− -- parsed value:
974− gParseJSON opts fargs = fmap M1 . gParseJSON' (tname :* opts :* fargs)
975− where
976− tname = moduleName proxy ++ "." ++ datatypeName proxy
977− proxy = undefined :: M1 _i d _f _p
978−
979−-- | 'GFromJSON', after unwrapping the 'D1' constructor, now carrying the data
980−-- type's name.
981−class GFromJSON' arity f where
982− gParseJSON' :: TypeName :* Options :* FromArgs arity a
983− -> Value
984− -> Parser (f a)
808+instance GFromJSON arity U1 where
809+ -- Empty constructors are expected to be encoded as an empty array:
810+ gParseJSON _opts _ v
811+ | isEmptyArray v = pure U1
812+ | otherwise = typeMismatch "unit constructor (U1)" v
985813
986−-- | Single constructor.
987814instance ( ConsFromJSON arity a
988815 , AllNullary (C1 c a) allNullary
989816 , ParseSum arity (C1 c a) allNullary
990− , Constructor c
991− ) => GFromJSON' arity (C1 c a) where
817+ ) => GFromJSON arity (D1 d (C1 c a)) where
992818 -- The option 'tagSingleConstructors' determines whether to wrap
993819 -- a single-constructor type.
994− gParseJSON' p@(_ :* opts :* _)
820+ gParseJSON opts fargs
995821 | tagSingleConstructors opts
996− = (unTagged :: Tagged allNullary (Parser (C1 c a p)) -> Parser (C1 c a p))
997− . parseSum p
998− | otherwise = fmap M1 . consParseJSON (cname :* p)
999− where
1000− cname = conName (undefined :: M1 _i c _f _p)
1001−
1002−-- | Multiple constructors.
1003−instance ( AllNullary (a :+: b) allNullary
1004− , ParseSum arity (a :+: b) allNullary
1005− ) => GFromJSON' arity (a :+: b) where
822+ = fmap M1
823+ . (unTagged :: Tagged allNullary (Parser (C1 c a p)) -> Parser (C1 c a p))
824+ . parseSum opts fargs
825+ | otherwise = fmap M1 . fmap M1 . consParseJSON opts fargs
826+
827+instance (ConsFromJSON arity a) => GFromJSON arity (C1 c a) where
828+ -- Constructors need to be decoded differently depending on whether they're
829+ -- a record or not. This distinction is made by consParseJSON:
830+ gParseJSON opts fargs = fmap M1 . consParseJSON opts fargs
831+
832+instance ( FromProduct arity a, FromProduct arity b
833+ , ProductSize a, ProductSize b
834+ ) => GFromJSON arity (a :*: b) where
835+ -- Products are expected to be encoded to an array. Here we check whether we
836+ -- got an array of the same size as the product, then parse each of the
837+ -- product's elements using parseProduct:
838+ gParseJSON opts fargs = withArray "product (:*:)" $ \arr ->
839+ let lenArray = V.length arr
840+ lenProduct = (unTagged2 :: Tagged2 (a :*: b) Int -> Int)
841+ productSize in
842+ if lenArray == lenProduct
843+ then parseProduct opts fargs arr 0 lenProduct
844+ else fail $ "When expecting a product of " ++ show lenProduct ++
845+ " values, encountered an Array of " ++ show lenArray ++
846+ " elements instead"
847+
848+instance ( AllNullary (a :+: b) allNullary
849+ , ParseSum arity (a :+: b) allNullary
850+ ) => GFromJSON arity (a :+: b) where
1006851 -- If all constructors of a sum datatype are nullary and the
1007852 -- 'allNullaryToStringTag' option is set they are expected to be
1008853 -- encoded as strings. This distinction is made by 'parseSum':
1009− gParseJSON' p =
1010− (unTagged :: Tagged allNullary (Parser ((a :+: b) _d)) ->
1011− Parser ((a :+: b) _d))
1012− . parseSum p
854+ gParseJSON opts fargs =
855+ (unTagged :: Tagged allNullary (Parser ((a :+: b) d)) ->
856+ Parser ((a :+: b) d))
857+ . parseSum opts fargs
858+
859+instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
860+ -- If an occurrence of the last type parameter is nested inside two
861+ -- composed types, it is decoded by using the outermost type's FromJSON1
862+ -- instance to generically decode the innermost type:
863+ gParseJSON opts fargs =
864+ let gpj = gParseJSON opts fargs in
865+ fmap Comp1 . liftParseJSON gpj (listParser gpj)
1013866
1014867--------------------------------------------------------------------------------
1015868
1016869class ParseSum arity f allNullary where
1017− parseSum :: TypeName :* Options :* FromArgs arity a
1018− -> Value
1019− -> Tagged allNullary (Parser (f a))
870+ parseSum :: Options -> FromArgs arity a
871+ -> Value -> Tagged allNullary (Parser (f a))
1020872
1021−instance ( ConstructorNames f
1022− , SumFromString f
873+instance ( SumFromString f
1023874 , FromPair arity f
1024875 , FromTaggedObject arity f
1025876 , FromUntaggedValue arity f
1026877 ) => ParseSum arity f True where
1027− parseSum p@(tname :* opts :* _)
1028− | allNullaryToStringTag opts = Tagged . parseAllNullarySum tname opts
1029− | otherwise = Tagged . parseNonAllNullarySum p
878+ parseSum opts fargs
879+ | allNullaryToStringTag opts = Tagged . parseAllNullarySum opts
880+ | otherwise = Tagged . parseNonAllNullarySum opts fargs
1030881
1031−instance ( ConstructorNames f
1032− , FromPair arity f
882+instance ( FromPair arity f
1033883 , FromTaggedObject arity f
1034884 , FromUntaggedValue arity f
1035885 ) => ParseSum arity f False where
1036− parseSum p = Tagged . parseNonAllNullarySum p
886+ parseSum opts fargs = Tagged . parseNonAllNullarySum opts fargs
1037887
1038888--------------------------------------------------------------------------------
1039889
1040−parseAllNullarySum :: (SumFromString f, ConstructorNames f)
1041− => TypeName -> Options -> Value -> Parser (f a)
1042−parseAllNullarySum tname opts =
1043− withText tname $ \tag ->
1044− maybe (badTag tag) return $
1045− parseSumFromString modifier tag
1046− where
1047− badTag tag = failWithCTags tname modifier $ \cnames ->
1048− "expected one of the tags " ++ show cnames ++
1049− ", but found tag " ++ show tag
1050− modifier = constructorTagModifier opts
1051−
1052−-- | Fail with an informative error message about a mismatched tag.
1053−-- The error message is parameterized by the list of expected tags,
1054−-- to be inferred from the result type of the parser.
1055−failWithCTags
1056− :: forall f a t. ConstructorNames f
1057− => TypeName -> (String -> t) -> ([t] -> String) -> Parser (f a)
1058−failWithCTags tname modifier f =
1059− contextType tname . fail $ f cnames
1060− where
1061− cnames = unTagged2 (constructorTags modifier :: Tagged2 f [t])
890+parseAllNullarySum :: SumFromString f => Options -> Value -> Parser (f a)
891+parseAllNullarySum opts = withText "Text" $ \key ->
892+ maybe (notFound key) return $
893+ parseSumFromString opts key
1062894
1063895class SumFromString f where
1064− parseSumFromString :: (String -> String) -> Text -> Maybe (f a)
896+ parseSumFromString :: Options -> Text -> Maybe (f a)
1065897
1066898instance (SumFromString a, SumFromString b) => SumFromString (a :+: b) where
1067899 parseSumFromString opts key = (L1 <$> parseSumFromString opts key) <|>
1068900 (R1 <$> parseSumFromString opts key)
1069901
1070902instance (Constructor c) => SumFromString (C1 c U1) where
1071− parseSumFromString modifier key
1072− | key == name = Just $ M1 U1
1073− | otherwise = Nothing
1074− where
1075− name = pack $ modifier $ conName (undefined :: M1 _i c _f _p)
1076−
1077−-- For genericFromJSONKey
1078−instance SumFromString a => SumFromString (D1 d a) where
1079− parseSumFromString modifier key = M1 <$> parseSumFromString modifier key
1080−
1081−-- | List of all constructor tags.
1082−constructorTags :: ConstructorNames a => (String -> t) -> Tagged2 a [t]
1083−constructorTags modifier =
1084− fmap DList.toList (constructorNames' modifier)
1085−
1086−-- | List of all constructor names of an ADT, after a given conversion
1087−-- function. (Better inlining.)
1088−class ConstructorNames a where
1089− constructorNames' :: (String -> t) -> Tagged2 a (DList.DList t)
1090−
1091−instance (ConstructorNames a, ConstructorNames b) => ConstructorNames (a :+: b) where
1092− constructorNames' = liftA2 append constructorNames' constructorNames'
1093− where
1094− append
1095− :: Tagged2 a (DList.DList t)
1096− -> Tagged2 b (DList.DList t)
1097− -> Tagged2 (a :+: b) (DList.DList t)
1098− append (Tagged2 xs) (Tagged2 ys) = Tagged2 (DList.append xs ys)
1099−
1100−instance Constructor c => ConstructorNames (C1 c a) where
1101− constructorNames' f = Tagged2 (pure (f cname))
1102− where
1103− cname = conName (undefined :: M1 _i c _f _p)
1104−
1105−-- For genericFromJSONKey
1106−instance ConstructorNames a => ConstructorNames (D1 d a) where
1107− constructorNames' = retag . constructorNames'
1108− where
1109− retag :: Tagged2 a u -> Tagged2 (D1 d a) u
1110− retag (Tagged2 x) = Tagged2 x
903+ parseSumFromString opts key | key == name = Just $ M1 U1
904+ | otherwise = Nothing
905+ where
906+ name = pack $ constructorTagModifier opts $
907+ conName (undefined :: t c U1 p)
1111908
1112909--------------------------------------------------------------------------------
1113−parseNonAllNullarySum :: forall f c arity.
1114− ( FromPair arity f
910+
911+parseNonAllNullarySum :: ( FromPair arity f
1115912 , FromTaggedObject arity f
1116913 , FromUntaggedValue arity f
1117− , ConstructorNames f
1118− ) => TypeName :* Options :* FromArgs arity c
914+ ) => Options -> FromArgs arity c
1119915 -> Value -> Parser (f c)
1120−parseNonAllNullarySum p@(tname :* opts :* _) =
916+parseNonAllNullarySum opts fargs =
1121917 case sumEncoding opts of
1122918 TaggedObject{..} ->
1123− withObject tname $ \obj -> do
1124− tag <- contextType tname . contextTag tagKey cnames_ $ obj .: tagKey
1125− fromMaybe (badTag tag <?> Key tagKey) $
1126− parseFromTaggedObject (tag :* contentsFieldName :* p) obj
1127− where
1128− tagKey = pack tagFieldName
1129− badTag tag = failWith_ $ \cnames ->
1130− "expected tag field to be one of " ++ show cnames ++
1131− ", but found tag " ++ show tag
1132− cnames_ = unTagged2 (constructorTags (constructorTagModifier opts) :: Tagged2 f [String])
919+ withObject "Object" $ \obj -> do
920+ tag <- obj .: pack tagFieldName
921+ fromMaybe (notFound tag) $
922+ parseFromTaggedObject opts fargs contentsFieldName obj tag
1133923
1134924 ObjectWithSingleField ->
1135− withObject tname $ \obj -> case H.toList obj of
1136− [(tag, v)] -> maybe (badTag tag) (<?> Key tag) $
1137− parsePair (tag :* p) v
1138− _ -> contextType tname . fail $
1139− "expected an Object with a single pair, but found " ++
1140− show (H.size obj) ++ " pairs"
1141− where
1142− badTag tag = failWith_ $ \cnames ->
1143− "expected an Object with a single pair where the tag is one of " ++
1144− show cnames ++ ", but found tag " ++ show tag
925+ withObject "Object" $ \obj ->
926+ case H.toList obj of
927+ [pair@(tag, _)] -> fromMaybe (notFound tag) $
928+ parsePair opts fargs pair
929+ _ -> fail "Object doesn't have a single field"
1145930
1146931 TwoElemArray ->
1147− withArray tname $ \arr -> case V.length arr of
1148− 2 | String tag <- V.unsafeIndex arr 0 ->
1149− maybe (badTag tag <?> Index 0) (<?> Index 1) $
1150− parsePair (tag :* p) (V.unsafeIndex arr 1)
1151− | otherwise ->
1152− contextType tname $
1153− fail "tag element is not a String" <?> Index 0
1154− len -> contextType tname . fail $
1155− "expected a 2-element Array, but encountered an Array of length " ++
1156− show len
1157− where
1158− badTag tag = failWith_ $ \cnames ->
1159− "expected tag of the 2-element Array to be one of " ++
1160− show cnames ++ ", but found tag " ++ show tag
932+ withArray "Array" $ \arr ->
933+ if V.length arr == 2
934+ then case V.unsafeIndex arr 0 of
935+ String tag -> fromMaybe (notFound tag) $
936+ parsePair opts fargs (tag, V.unsafeIndex arr 1)
937+ _ -> fail "First element is not a String"
938+ else fail "Array doesn't have 2 elements"
1161939
1162− UntaggedValue -> parseUntaggedValue p
1163− where
1164− failWith_ = failWithCTags tname (constructorTagModifier opts)
940+ UntaggedValue -> parseUntaggedValue opts fargs
1165941
1166942--------------------------------------------------------------------------------
1167943
1168944class FromTaggedObject arity f where
1169− -- The first two components of the parameter tuple are: the constructor tag
1170− -- to match against, and the contents field name.
1171− parseFromTaggedObject
1172− :: Text :* String :* TypeName :* Options :* FromArgs arity a
1173− -> Object
1174− -> Maybe (Parser (f a))
945+ parseFromTaggedObject :: Options -> FromArgs arity a
946+ -> String -> Object
947+ -> Text -> Maybe (Parser (f a))
1175948
1176949instance ( FromTaggedObject arity a, FromTaggedObject arity b) =>
1177950 FromTaggedObject arity (a :+: b) where
1178− parseFromTaggedObject p obj =
1179− (fmap L1 <$> parseFromTaggedObject p obj) <|>
1180− (fmap R1 <$> parseFromTaggedObject p obj)
951+ parseFromTaggedObject opts fargs contentsFieldName obj tag =
952+ (fmap L1 <$> parseFromTaggedObject opts fargs contentsFieldName obj tag) <|>
953+ (fmap R1 <$> parseFromTaggedObject opts fargs contentsFieldName obj tag)
1181954
1182−instance ( IsRecord f isRecord
1183− , FromTaggedObject' arity f isRecord
955+instance ( FromTaggedObject' arity f
1184956 , Constructor c
1185957 ) => FromTaggedObject arity (C1 c f) where
1186− parseFromTaggedObject (tag :* contentsFieldName :* p@(_ :* opts :* _))
1187− | tag == tag'
1188− = Just . fmap M1 .
1189− (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
1190− parseFromTaggedObject' (contentsFieldName :* cname :* p)
1191− | otherwise = const Nothing
1192− where
1193− tag' = pack $ constructorTagModifier opts cname
1194− cname = conName (undefined :: M1 _i c _f _p)
958+ parseFromTaggedObject opts fargs contentsFieldName obj tag
959+ | tag == name = Just $ M1 <$> parseFromTaggedObject'
960+ opts fargs contentsFieldName obj
961+ | otherwise = Nothing
962+ where
963+ name = pack $ constructorTagModifier opts $
964+ conName (undefined :: t c f p)
1195965
1196966--------------------------------------------------------------------------------
1197967
1198−class FromTaggedObject' arity f isRecord where
1199− -- The first component of the parameter tuple is the contents field name.
1200− parseFromTaggedObject'
1201− :: String :* ConName :* TypeName :* Options :* FromArgs arity a
1202− -> Object -> Tagged isRecord (Parser (f a))
1203−
1204−instance (RecordFromJSON arity f, FieldNames f) => FromTaggedObject' arity f True where
1205− -- Records are unpacked in the tagged object
1206− parseFromTaggedObject' (_ :* p) = Tagged . recordParseJSON (True :* p)
1207−
1208−instance (ConsFromJSON arity f) => FromTaggedObject' arity f False where
1209− -- Nonnullary nonrecords are encoded in the contents field
1210− parseFromTaggedObject' p obj = Tagged $ do
1211− contents <- contextCons cname tname (obj .: key)
1212− consParseJSON p' contents <?> Key key
1213− where
1214− key = pack contentsFieldName
1215− contentsFieldName :* p'@(cname :* tname :* _) = p
968+class FromTaggedObject' arity f where
969+ parseFromTaggedObject' :: Options -> FromArgs arity a -> String
970+ -> Object -> Parser (f a)
971+
972+class FromTaggedObject'' arity f isRecord where
973+ parseFromTaggedObject'' :: Options -> FromArgs arity a -> String
974+ -> Object -> Tagged isRecord (Parser (f a))
975+
976+instance ( IsRecord f isRecord
977+ , FromTaggedObject'' arity f isRecord
978+ ) => FromTaggedObject' arity f where
979+ parseFromTaggedObject' opts fargs contentsFieldName =
980+ (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
981+ parseFromTaggedObject'' opts fargs contentsFieldName
1216982
1217−instance OVERLAPPING_ FromTaggedObject' arity U1 False where
1218− -- Nullary constructors don't need a contents field
1219− parseFromTaggedObject' _ _ = Tagged (pure U1)
983+instance (FromRecord arity f) => FromTaggedObject'' arity f True where
984+ parseFromTaggedObject'' opts fargs _ =
985+ Tagged . parseRecord opts fargs
986+
987+instance (GFromJSON arity f) => FromTaggedObject'' arity f False where
988+ parseFromTaggedObject'' opts fargs contentsFieldName = Tagged .
989+ (gParseJSON opts fargs <=< (.: pack contentsFieldName))
990+
991+instance OVERLAPPING_ FromTaggedObject'' arity U1 False where
992+ parseFromTaggedObject'' _ _ _ _ = Tagged (pure U1)
1220993
1221994--------------------------------------------------------------------------------
1222995
1223−-- | Constructors need to be decoded differently depending on whether they're
1224−-- a record or not. This distinction is made by 'ConsParseJSON'.
1225996class ConsFromJSON arity f where
1226− consParseJSON
1227− :: ConName :* TypeName :* Options :* FromArgs arity a
1228− -> Value -> Parser (f a)
997+ consParseJSON :: Options -> FromArgs arity a
998+ -> Value -> Parser (f a)
1229999
12301000class ConsFromJSON' arity f isRecord where
1231− consParseJSON'
1232− :: ConName :* TypeName :* Options :* FromArgs arity a
1233− -> Value -> Tagged isRecord (Parser (f a))
1001+ consParseJSON' :: Options -> FromArgs arity a
1002+ -> Value -> Tagged isRecord (Parser (f a))
12341003
12351004instance ( IsRecord f isRecord
12361005 , ConsFromJSON' arity f isRecord
12371006 ) => ConsFromJSON arity f where
1238− consParseJSON p =
1007+ consParseJSON opts fargs =
12391008 (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a))
1240− . consParseJSON' p
1009+ . consParseJSON' opts fargs
12411010
12421011instance OVERLAPPING_
1243− ( GFromJSON arity a, RecordFromJSON arity (S1 s a)
1012+ ( GFromJSON arity a, FromRecord arity (S1 s a)
12441013 ) => ConsFromJSON' arity (S1 s a) True where
1245− consParseJSON' p@(cname :* tname :* opts :* fargs)
1246− | unwrapUnaryRecords opts = Tagged . fmap M1 . gParseJSON opts fargs
1247− | otherwise = Tagged . withObject (showCons cname tname) (recordParseJSON (False :* p))
1014+ consParseJSON' opts fargs
1015+ | unwrapUnaryRecords opts = Tagged . gParseJSON opts fargs
1016+ | otherwise = Tagged . withObject "unary record" (parseRecord opts fargs)
12481017
1249−instance RecordFromJSON arity f => ConsFromJSON' arity f True where
1250− consParseJSON' p@(cname :* tname :* _) =
1251− Tagged . withObject (showCons cname tname) (recordParseJSON (False :* p))
1018+instance FromRecord arity f => ConsFromJSON' arity f True where
1019+ consParseJSON' opts fargs =
1020+ Tagged . withObject "record (:*:)" (parseRecord opts fargs)
12521021
1253−instance OVERLAPPING_
1254− ConsFromJSON' arity U1 False where
1255− -- Empty constructors are expected to be encoded as an empty array:
1256− consParseJSON' (cname :* tname :* _) v =
1257− Tagged . contextCons cname tname $ case v of
1258− Array a | V.null a -> pure U1
1259− | otherwise -> fail_ a
1260− _ -> typeMismatch "Array" v
1261− where
1262− fail_ a = fail $
1263− "expected an empty Array, but encountered an Array of length " ++
1264− show (V.length a)
1265−
1266−instance OVERLAPPING_
1267− GFromJSON arity f => ConsFromJSON' arity (S1 s f) False where
1268− consParseJSON' (_ :* _ :* opts :* fargs) =
1269− Tagged . fmap M1 . gParseJSON opts fargs
1270−
1271−instance (ProductFromJSON arity f, ProductSize f
1272− ) => ConsFromJSON' arity f False where
1273− consParseJSON' p = Tagged . productParseJSON0 p
1022+instance GFromJSON arity f => ConsFromJSON' arity f False where
1023+ consParseJSON' opts fargs = Tagged . gParseJSON opts fargs
12741024
12751025--------------------------------------------------------------------------------
12761026
1277−class FieldNames f where
1278− fieldNames :: f a -> [Text] -> [Text]
1027+class FromRecord arity f where
1028+ parseRecord :: Options -> FromArgs arity a
1029+ -> Object -> Parser (f a)
12791030
1280−instance (FieldNames a, FieldNames b) => FieldNames (a :*: b) where
1281− fieldNames _ =
1282− fieldNames (undefined :: a x) .
1283− fieldNames (undefined :: b y)
1284−
1285−instance (Selector s) => FieldNames (S1 s f) where
1286− fieldNames _ = (pack (selName (undefined :: M1 _i s _f _p)) :)
1287−
1288−class RecordFromJSON arity f where
1289− recordParseJSON
1290− :: Bool :* ConName :* TypeName :* Options :* FromArgs arity a
1291− -> Object -> Parser (f a)
1292−
1293−instance ( FieldNames f
1294− , RecordFromJSON' arity f
1295− ) => RecordFromJSON arity f where
1296− recordParseJSON (fromTaggedSum :* p@(cname :* tname :* opts :* _)) =
1297− \obj -> checkUnknown obj >> recordParseJSON' p obj
1298− where
1299− knownFields :: H.HashMap Text ()
1300− knownFields = H.fromList $ map (,()) $
1301− fieldNames (undefined :: f a)
1302− [pack (tagFieldName (sumEncoding opts)) | fromTaggedSum]
1303− checkUnknown =
1304− if not (rejectUnknownFields opts)
1305− then \_ -> return ()
1306− else \obj -> case H.keys (H.difference obj knownFields) of
1307− [] -> return ()
1308− unknownFields -> contextCons cname tname $
1309− fail ("unknown fields: " ++ show unknownFields)
1310−
1311−class RecordFromJSON' arity f where
1312− recordParseJSON'
1313− :: ConName :* TypeName :* Options :* FromArgs arity a
1314− -> Object -> Parser (f a)
1315−
1316−instance ( RecordFromJSON' arity a
1317− , RecordFromJSON' arity b
1318− ) => RecordFromJSON' arity (a :*: b) where
1319− recordParseJSON' p obj =
1320− (:*:) <$> recordParseJSON' p obj
1321− <*> recordParseJSON' p obj
1031+instance ( FromRecord arity a
1032+ , FromRecord arity b
1033+ ) => FromRecord arity (a :*: b) where
1034+ parseRecord opts fargs obj =
1035+ (:*:) <$> parseRecord opts fargs obj
1036+ <*> parseRecord opts fargs obj
13221037
13231038instance OVERLAPPABLE_ (Selector s, GFromJSON arity a) =>
1324− RecordFromJSON' arity (S1 s a) where
1325− recordParseJSON' (cname :* tname :* opts :* fargs) obj = do
1326− fv <- contextCons cname tname (obj .: label)
1327− M1 <$> gParseJSON opts fargs fv <?> Key label
1328− where
1329− label = pack $ fieldLabelModifier opts sname
1330− sname = selName (undefined :: M1 _i s _f _p)
1039+ FromRecord arity (S1 s a) where
1040+ parseRecord opts fargs =
1041+ (<?> Key label) . gParseJSON opts fargs <=< (.: label)
1042+ where
1043+ label = pack . fieldLabelModifier opts $ selName (undefined :: t s a p)
13311044
13321045instance INCOHERENT_ (Selector s, FromJSON a) =>
1333− RecordFromJSON' arity (S1 s (K1 i (Maybe a))) where
1334− recordParseJSON' (_ :* _ :* opts :* _) obj = M1 . K1 <$> obj .:? pack label
1335− where
1336− label = fieldLabelModifier opts sname
1337− sname = selName (undefined :: M1 _i s _f _p)
1046+ FromRecord arity (S1 s (K1 i (Maybe a))) where
1047+ parseRecord opts _ obj = M1 . K1 <$> obj .:? pack label
1048+ where
1049+ label = fieldLabelModifier opts $
1050+ selName (undefined :: t s (K1 i (Maybe a)) p)
13381051
13391052-- Parse an Option like a Maybe.
13401053instance INCOHERENT_ (Selector s, FromJSON a) =>
1341− RecordFromJSON' arity (S1 s (K1 i (Semigroup.Option a))) where
1342− recordParseJSON' p obj = wrap <$> recordParseJSON' p obj
1054+ FromRecord arity (S1 s (K1 i (Semigroup.Option a))) where
1055+ parseRecord opts fargs obj = wrap <$> parseRecord opts fargs obj
13431056 where
13441057 wrap :: S1 s (K1 i (Maybe a)) p -> S1 s (K1 i (Semigroup.Option a)) p
13451058 wrap (M1 (K1 a)) = M1 (K1 (Semigroup.Option a))
13461059
13471060--------------------------------------------------------------------------------
13481061
1349−productParseJSON0
1350− :: forall f arity a. (ProductFromJSON arity f, ProductSize f)
1351− => ConName :* TypeName :* Options :* FromArgs arity a
1352− -> Value -> Parser (f a)
1353− -- Products are expected to be encoded to an array. Here we check whether we
1354− -- got an array of the same size as the product, then parse each of the
1355− -- product's elements using productParseJSON:
1356−productParseJSON0 p@(cname :* tname :* _ :* _) =
1357− withArray (showCons cname tname) $ \arr ->
1358− let lenArray = V.length arr
1359− lenProduct = (unTagged2 :: Tagged2 f Int -> Int)
1360− productSize in
1361− if lenArray == lenProduct
1362− then productParseJSON p arr 0 lenProduct
1363− else contextCons cname tname $
1364− fail $ "expected an Array of length " ++ show lenProduct ++
1365− ", but encountered an Array of length " ++ show lenArray
1366−
1367−--
1368−
1369−class ProductFromJSON arity f where
1370− productParseJSON :: ConName :* TypeName :* Options :* FromArgs arity a
1062+class FromProduct arity f where
1063+ parseProduct :: Options -> FromArgs arity a
13711064 -> Array -> Int -> Int
13721065 -> Parser (f a)
13731066
1374−instance ( ProductFromJSON arity a
1375− , ProductFromJSON arity b
1376− ) => ProductFromJSON arity (a :*: b) where
1377− productParseJSON p arr ix len =
1378− (:*:) <$> productParseJSON p arr ix lenL
1379− <*> productParseJSON p arr ixR lenR
1067+instance ( FromProduct arity a
1068+ , FromProduct arity b
1069+ ) => FromProduct arity (a :*: b) where
1070+ parseProduct opts fargs arr ix len =
1071+ (:*:) <$> parseProduct opts fargs arr ix lenL
1072+ <*> parseProduct opts fargs arr ixR lenR
13801073 where
13811074 lenL = len `unsafeShiftR` 1
13821075 ixR = ix + lenL
13831076 lenR = len - lenL
13841077
1385−instance (GFromJSON arity a) => ProductFromJSON arity (S1 s a) where
1386− productParseJSON (_ :* _ :* opts :* fargs) arr ix _ =
1387− M1 <$> gParseJSON opts fargs (V.unsafeIndex arr ix) <?> Index ix
1078+instance (GFromJSON arity a) => FromProduct arity (S1 s a) where
1079+ parseProduct opts fargs arr ix _ =
1080+ gParseJSON opts fargs $ V.unsafeIndex arr ix
13881081
13891082--------------------------------------------------------------------------------
13901083
13911084class FromPair arity f where
1392− -- The first component of the parameter tuple is the tag to match.
1393− parsePair :: Text :* TypeName :* Options :* FromArgs arity a
1394− -> Value
1395− -> Maybe (Parser (f a))
1085+ parsePair :: Options -> FromArgs arity a
1086+ -> Pair -> Maybe (Parser (f a))
13961087
13971088instance ( FromPair arity a
13981089 , FromPair arity b
13991090 ) => FromPair arity (a :+: b) where
1400− parsePair p pair =
1401− (fmap L1 <$> parsePair p pair) <|>
1402− (fmap R1 <$> parsePair p pair)
1091+ parsePair opts fargs pair = (fmap L1 <$> parsePair opts fargs pair) <|>
1092+ (fmap R1 <$> parsePair opts fargs pair)
14031093
14041094instance ( Constructor c
1095+ , GFromJSON arity a
14051096 , ConsFromJSON arity a
14061097 ) => FromPair arity (C1 c a) where
1407− parsePair (tag :* p@(_ :* opts :* _)) v
1408− | tag == tag' = Just $ M1 <$> consParseJSON (cname :* p) v
1098+ parsePair opts fargs (tag, value)
1099+ | tag == tag' = Just $ gParseJSON opts fargs value
14091100 | otherwise = Nothing
1410− where
1411− tag' = pack $ constructorTagModifier opts cname
1412− cname = conName (undefined :: M1 _i c _a _p)
1101+ where
1102+ tag' = pack $ constructorTagModifier opts $
1103+ conName (undefined :: t c a p)
14131104
14141105--------------------------------------------------------------------------------
14151106
14161107class FromUntaggedValue arity f where
1417− parseUntaggedValue :: TypeName :* Options :* FromArgs arity a
1418− -> Value
1419− -> Parser (f a)
1108+ parseUntaggedValue :: Options -> FromArgs arity a
1109+ -> Value -> Parser (f a)
14201110
14211111instance
14221112 ( FromUntaggedValue arity a
14231113 , FromUntaggedValue arity b
14241114 ) => FromUntaggedValue arity (a :+: b)
14251115 where
1426− parseUntaggedValue p value =
1427− L1 <$> parseUntaggedValue p value <|>
1428− R1 <$> parseUntaggedValue p value
1116+ parseUntaggedValue opts fargs value =
1117+ L1 <$> parseUntaggedValue opts fargs value <|>
1118+ R1 <$> parseUntaggedValue opts fargs value
14291119
14301120instance OVERLAPPABLE_
1431− ( ConsFromJSON arity a
1432− , Constructor c
1121+ ( GFromJSON arity a
1122+ , ConsFromJSON arity a
14331123 ) => FromUntaggedValue arity (C1 c a)
14341124 where
1435− parseUntaggedValue p = fmap M1 . consParseJSON (cname :* p)
1436− where
1437− cname = conName (undefined :: M1 _i c _f _p)
1125+ parseUntaggedValue = gParseJSON
14381126
14391127instance OVERLAPPING_
14401128 ( Constructor c )
14411129 => FromUntaggedValue arity (C1 c U1)
14421130 where
1443− parseUntaggedValue (tname :* opts :* _) v =
1444− contextCons cname tname $ case v of
1445− String tag
1446− | tag == tag' -> pure $ M1 U1
1447− | otherwise -> fail_ tag
1448− _ -> typeMismatch "String" v
1449− where
1450− tag' = pack $ constructorTagModifier opts cname
1451− cname = conName (undefined :: M1 _i c _f _p)
1452− fail_ tag = fail $
1453− "expected tag " ++ show tag' ++ ", but found tag " ++ show tag
1131+ parseUntaggedValue opts _ (String s)
1132+ | s == pack (constructorTagModifier opts (conName (undefined :: t c U1 p))) =
1133+ pure $ M1 U1
1134+ | otherwise =
1135+ fail $ "Invalid tag: " ++ unpack s
1136+ parseUntaggedValue _ _ v = typeMismatch (conName (undefined :: t c U1 p)) v
1137+
1138+
1139+--------------------------------------------------------------------------------
1140+
1141+notFound :: Text -> Parser a
1142+notFound key = fail $ "The key \"" ++ unpack key ++ "\" was not found"
1143+{-# INLINE notFound #-}
14541144
14551145-------------------------------------------------------------------------------
14561146-- Instances
@@ -1508,20 +1198,17 @@ instance (FromJSON a, FromJSON b) => FromJSON (Either a b) where
15081198 parseJSON = parseJSON2
15091199 {-# INLINE parseJSON #-}
15101200
1511−instance FromJSON Void where
1512− parseJSON _ = fail "Cannot parse Void"
1513− {-# INLINE parseJSON #-}
1201+
15141202
15151203instance FromJSON Bool where
1516− parseJSON (Bool b) = pure b
1517− parseJSON v = typeMismatch "Bool" v
1204+ parseJSON = withBool "Bool" pure
15181205 {-# INLINE parseJSON #-}
15191206
15201207instance FromJSONKey Bool where
15211208 fromJSONKey = FromJSONKeyTextParser $ \t -> case t of
15221209 "true" -> pure True
15231210 "false" -> pure False
1524− _ -> fail $ "cannot parse key " ++ show t ++ " into Bool"
1211+ _ -> fail $ "Cannot parse key into Bool: " ++ T.unpack t
15251212
15261213instance FromJSON Ordering where
15271214 parseJSON = withText "Ordering" $ \s ->
@@ -1529,30 +1216,25 @@ instance FromJSON Ordering where
15291216 "LT" -> return LT
15301217 "EQ" -> return EQ
15311218 "GT" -> return GT
1532− _ -> fail $ "parsing Ordering failed, unexpected " ++ show s ++
1533− " (expected \"LT\", \"EQ\", or \"GT\")"
1219+ _ -> fail "Parsing Ordering value failed: expected \"LT\", \"EQ\", or \"GT\""
15341220
15351221instance FromJSON () where
15361222 parseJSON = withArray "()" $ \v ->
15371223 if V.null v
15381224 then pure ()
1539− else prependContext "()" $ fail "expected an empty array"
1225+ else fail "Expected an empty array"
15401226 {-# INLINE parseJSON #-}
15411227
15421228instance FromJSON Char where
1543− parseJSON = withText "Char" parseChar
1229+ parseJSON = withText "Char" $ \t ->
1230+ if T.compareLength t 1 == EQ
1231+ then pure $ T.head t
1232+ else fail "Expected a string of length 1"
15441233 {-# INLINE parseJSON #-}
15451234
1546− parseJSONList (String s) = pure (T.unpack s)
1547− parseJSONList v = typeMismatch "String" v
1235+ parseJSONList = withText "String" $ pure . T.unpack
15481236 {-# INLINE parseJSONList #-}
15491237
1550−parseChar :: Text -> Parser Char
1551−parseChar t =
1552− if T.compareLength t 1 == EQ
1553− then pure $ T.head t
1554− else prependContext "Char" $ fail "expected a string of length 1"
1555−
15561238instance FromJSON Double where
15571239 parseJSON = parseRealFloat "Double"
15581240 {-# INLINE parseJSON #-}
@@ -1576,22 +1258,12 @@ instance FromJSONKey Float where
15761258 _ -> Scientific.toRealFloat <$> parseScientificText t
15771259
15781260instance (FromJSON a, Integral a) => FromJSON (Ratio a) where
1579− parseJSON (Number x)
1580− | exp10 <= 1024
1581− , exp10 >= -1024 = return $! realToFrac x
1582− | otherwise = prependContext "Ratio" $ fail msg
1583− where
1584− exp10 = base10Exponent x
1585− msg = "found a number with exponent " ++ show exp10
1586− ++ ", but it must not be greater than 1024 or less than -1024"
1587− parseJSON o = objParser o
1588− where
1589− objParser = withObject "Rational" $ \obj -> do
1590− numerator <- obj .: "numerator"
1591− denominator <- obj .: "denominator"
1592− if denominator == 0
1593− then fail "Ratio denominator was 0"
1594− else pure $ numerator % denominator
1261+ parseJSON = withObject "Rational" $ \obj -> do
1262+ numerator <- obj .: "numerator"
1263+ denominator <- obj .: "denominator"
1264+ if denominator == 0
1265+ then fail "Ratio denominator was 0"
1266+ else pure $ numerator % denominator
15951267 {-# INLINE parseJSON #-}
15961268
15971269-- | This instance includes a bounds check to prevent maliciously
@@ -1599,7 +1271,7 @@ instance (FromJSON a, Integral a) => FromJSON (Ratio a) where
15991271-- newtype 'Scientific' and provide your own instance using
16001272-- 'withScientific' if you want to allow larger inputs.
16011273instance HasResolution a => FromJSON (Fixed a) where
1602− parseJSON = prependContext "Fixed" . withBoundedScientific' (pure . realToFrac)
1274+ parseJSON = withBoundedScientific "Fixed" $ pure . realToFrac
16031275 {-# INLINE parseJSON #-}
16041276
16051277instance FromJSON Int where
@@ -1622,20 +1294,19 @@ instance FromJSONKey Integer where
16221294
16231295instance FromJSON Natural where
16241296 parseJSON value = do
1625− integer <- parseIntegral "Natural" value
1626− parseNatural integer
1297+ integer :: Integer <- parseIntegral "Natural" value
1298+ if integer < 0 then
1299+ fail $ "expected Natural, encountered negative number " <> show integer
1300+ else
1301+ pure $ fromIntegral integer
16271302
16281303instance FromJSONKey Natural where
16291304 fromJSONKey = FromJSONKeyTextParser $ \text -> do
1630− integer <- parseIntegralText "Natural" text
1631− parseNatural integer
1632−
1633−parseNatural :: Integer -> Parser Natural
1634−parseNatural integer =
1635− if integer < 0 then
1636− fail $ "parsing Natural failed, unexpected negative number " <> show integer
1637− else
1638− pure $ fromIntegral integer
1305+ integer :: Integer <- parseIntegralText "Natural" text
1306+ if integer < 0 then
1307+ fail $ "expected Natural, encountered negative number " <> show integer
1308+ else
1309+ pure $ fromIntegral integer
16391310
16401311instance FromJSON Int8 where
16411312 parseJSON = parseBoundedIntegral "Int8"
@@ -1732,17 +1403,17 @@ parseVersionText = go . readP_to_S parseVersion . unpack
17321403 where
17331404 go [(v,[])] = return v
17341405 go (_ : xs) = go xs
1735− go _ = fail "parsing Version failed"
1406+ go _ = fail "could not parse Version"
17361407
17371408-------------------------------------------------------------------------------
17381409-- semigroups NonEmpty
17391410-------------------------------------------------------------------------------
17401411
17411412instance FromJSON1 NonEmpty where
1742− liftParseJSON p _ = withArray "NonEmpty" $
1413+ liftParseJSON p _ = withArray "NonEmpty a" $
17431414 (>>= ne) . Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
17441415 where
1745− ne [] = fail "parsing NonEmpty failed, unexpected empty list"
1416+ ne [] = fail "Expected a NonEmpty but got an empty list"
17461417 ne (x:xs) = pure (x :| xs)
17471418 {-# INLINE liftParseJSON #-}
17481419
@@ -1763,7 +1434,7 @@ instance FromJSON Scientific where
17631434-------------------------------------------------------------------------------
17641435
17651436instance FromJSON1 DList.DList where
1766− liftParseJSON p _ = withArray "DList" $
1437+ liftParseJSON p _ = withArray "DList a" $
17671438 fmap DList.fromList .
17681439 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
17691440 {-# INLINE liftParseJSON #-}
@@ -1840,7 +1511,7 @@ instance (FromJSON1 f, FromJSON1 g) => FromJSON1 (Sum f g) where
18401511 inr = "InR"
18411512
18421513 liftParseJSON _ _ _ = fail $
1843− "parsing Sum failed, expected an object with a single property " ++
1514+ "expected an object with a single property " ++
18441515 "where the property key should be either " ++
18451516 "\"InL\" or \"InR\""
18461517 {-# INLINE liftParseJSON #-}
@@ -1854,7 +1525,7 @@ instance (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Sum f g a) where
18541525-------------------------------------------------------------------------------
18551526
18561527instance FromJSON1 Seq.Seq where
1857− liftParseJSON p _ = withArray "Seq" $
1528+ liftParseJSON p _ = withArray "Seq a" $
18581529 fmap Seq.fromList .
18591530 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
18601531 {-# INLINE liftParseJSON #-}
@@ -1888,13 +1559,13 @@ instance FromJSON a => FromJSON (IntMap.IntMap a) where
18881559
18891560instance (FromJSONKey k, Ord k) => FromJSON1 (M.Map k) where
18901561 liftParseJSON p _ = case fromJSONKey of
1891− FromJSONKeyCoerce _ -> withObject "Map" $
1562+ FromJSONKeyCoerce _-> withObject "Map k v" $
18921563 fmap (H.foldrWithKey (M.insert . unsafeCoerce) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1893− FromJSONKeyText f -> withObject "Map" $
1564+ FromJSONKeyText f -> withObject "Map k v" $
18941565 fmap (H.foldrWithKey (M.insert . f) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1895− FromJSONKeyTextParser f -> withObject "Map" $
1566+ FromJSONKeyTextParser f -> withObject "Map k v" $
18961567 H.foldrWithKey (\k v m -> M.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure M.empty)
1897− FromJSONKeyValue f -> withArray "Map" $ \arr ->
1568+ FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
18981569 fmap M.fromList . Tr.sequence .
18991570 zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
19001571 {-# INLINE liftParseJSON #-}
@@ -1922,18 +1593,18 @@ instance (FromJSON v) => FromJSON (Tree.Tree v) where
19221593
19231594instance FromJSON UUID.UUID where
19241595 parseJSON = withText "UUID" $
1925− maybe (fail "invalid UUID") pure . UUID.fromText
1596+ maybe (fail "Invalid UUID") pure . UUID.fromText
19261597
19271598instance FromJSONKey UUID.UUID where
19281599 fromJSONKey = FromJSONKeyTextParser $
1929− maybe (fail "invalid UUID") pure . UUID.fromText
1600+ maybe (fail "Invalid UUID") pure . UUID.fromText
19301601
19311602-------------------------------------------------------------------------------
19321603-- vector
19331604-------------------------------------------------------------------------------
19341605
19351606instance FromJSON1 Vector where
1936− liftParseJSON p _ = withArray "Vector" $
1607+ liftParseJSON p _ = withArray "Vector a" $
19371608 V.mapM (uncurry $ parseIndexedJSON p) . V.indexed
19381609 {-# INLINE liftParseJSON #-}
19391610
@@ -1947,14 +1618,14 @@ vectorParseJSON s = withArray s $ fmap V.convert . V.mapM (uncurry $ parseIndexe
19471618{-# INLINE vectorParseJSON #-}
19481619
19491620instance (Storable a, FromJSON a) => FromJSON (VS.Vector a) where
1950− parseJSON = vectorParseJSON "Data.Vector.Storable.Vector"
1621+ parseJSON = vectorParseJSON "Data.Vector.Storable.Vector a"
19511622
19521623instance (VP.Prim a, FromJSON a) => FromJSON (VP.Vector a) where
1953− parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector"
1624+ parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector a"
19541625 {-# INLINE parseJSON #-}
19551626
19561627instance (VG.Vector VU.Vector a, FromJSON a) => FromJSON (VU.Vector a) where
1957− parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector"
1628+ parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector a"
19581629 {-# INLINE parseJSON #-}
19591630
19601631-------------------------------------------------------------------------------
@@ -1968,13 +1639,13 @@ instance (Eq a, Hashable a, FromJSON a) => FromJSON (HashSet.HashSet a) where
19681639
19691640instance (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (H.HashMap k) where
19701641 liftParseJSON p _ = case fromJSONKey of
1971− FromJSONKeyCoerce _ -> withObject "HashMap ~Text" $
1642+ FromJSONKeyCoerce _ -> withObject "HashMap ~Text v" $
19721643 uc . H.traverseWithKey (\k v -> p v <?> Key k)
1973− FromJSONKeyText f -> withObject "HashMap" $
1644+ FromJSONKeyText f -> withObject "HashMap k v" $
19741645 fmap (mapKey f) . H.traverseWithKey (\k v -> p v <?> Key k)
1975− FromJSONKeyTextParser f -> withObject "HashMap" $
1646+ FromJSONKeyTextParser f -> withObject "HashMap k v" $
19761647 H.foldrWithKey (\k v m -> H.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure H.empty)
1977− FromJSONKeyValue f -> withArray "Map" $ \arr ->
1648+ FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
19781649 fmap H.fromList . Tr.sequence .
19791650 zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
19801651 where
@@ -1997,33 +1668,11 @@ instance FromJSON DotNetTime where
19971668 parseJSON = withText "DotNetTime" $ \t ->
19981669 let (s,m) = T.splitAt (T.length t - 5) t
19991670 t' = T.concat [s,".",m]
2000− in case parseTimeM True defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
1671+ in case parseTime defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
20011672 Just d -> pure (DotNetTime d)
20021673 _ -> fail "could not parse .NET time"
20031674 {-# INLINE parseJSON #-}
20041675
2005−-------------------------------------------------------------------------------
2006−-- primitive
2007−-------------------------------------------------------------------------------
2008−
2009−instance FromJSON a => FromJSON (PM.Array a) where
2010− -- note: we could do better than this if vector exposed the data
2011− -- constructor in Data.Vector.
2012− parseJSON = fmap Exts.fromList . parseJSON
2013−
2014−instance FromJSON a => FromJSON (PM.SmallArray a) where
2015− parseJSON = fmap Exts.fromList . parseJSON
2016−
2017−#if MIN_VERSION_primitive(0,6,4)
2018−instance (PM.Prim a,FromJSON a) => FromJSON (PM.PrimArray a) where
2019− parseJSON = fmap Exts.fromList . parseJSON
2020−
2021−#if !MIN_VERSION_primitive(0,7,0)
2022−instance (PM.PrimUnlifted a,FromJSON a) => FromJSON (PM.UnliftedArray a) where
2023− parseJSON = fmap Exts.fromList . parseJSON
2024−#endif
2025−#endif
2026−
20271676-------------------------------------------------------------------------------
20281677-- time
20291678-------------------------------------------------------------------------------
@@ -2091,40 +1740,6 @@ instance FromJSON DiffTime where
20911740 parseJSON = withBoundedScientific "DiffTime" $ pure . realToFrac
20921741 {-# INLINE parseJSON #-}
20931742
2094−instance FromJSON SystemTime where
2095− parseJSON v = prependContext "SystemTime" $ do
2096− n <- parseJSON v
2097− let n' = floor (n * fromInteger (resolution n) :: Nano)
2098− let (secs, nano) = n' `divMod` resolution n
2099− return (MkSystemTime (fromInteger secs) (fromInteger nano))
2100−
2101−instance FromJSON CalendarDiffTime where
2102− parseJSON = withObject "CalendarDiffTime" $ \obj -> CalendarDiffTime
2103− <$> obj .: "months"
2104− <*> obj .: "time"
2105−
2106−instance FromJSON CalendarDiffDays where
2107− parseJSON = withObject "CalendarDiffDays" $ \obj -> CalendarDiffDays
2108− <$> obj .: "months"
2109− <*> obj .: "days"
2110−
2111−instance FromJSON DayOfWeek where
2112− parseJSON = withText "DaysOfWeek" parseDayOfWeek
2113−
2114−parseDayOfWeek :: T.Text -> Parser DayOfWeek
2115−parseDayOfWeek t = case T.toLower t of
2116− "monday" -> return Monday
2117− "tuesday" -> return Tuesday
2118− "wednesday" -> return Wednesday
2119− "thursday" -> return Thursday
2120− "friday" -> return Friday
2121− "saturday" -> return Saturday
2122− "sunday" -> return Sunday
2123− _ -> fail "Invalid week day"
2124−
2125−instance FromJSONKey DayOfWeek where
2126− fromJSONKey = FromJSONKeyTextParser parseDayOfWeek
2127−
21281743-------------------------------------------------------------------------------
21291744-- base Monoid/Semigroup
21301745-------------------------------------------------------------------------------
@@ -2245,15 +1860,14 @@ instance FromJSON a => FromJSON (Semigroup.Option a) where
22451860
22461861instance FromJSON1 Proxy where
22471862 {-# INLINE liftParseJSON #-}
2248− liftParseJSON _ _ = fromNull "Proxy" Proxy
1863+ liftParseJSON _ _ Null = pure Proxy
1864+ liftParseJSON _ _ v = typeMismatch "Proxy" v
22491865
22501866instance FromJSON (Proxy a) where
22511867 {-# INLINE parseJSON #-}
2252− parseJSON = fromNull "Proxy" Proxy
1868+ parseJSON Null = pure Proxy
1869+ parseJSON v = typeMismatch "Proxy" v
22531870
2254−fromNull :: String -> a -> Value -> Parser a
2255−fromNull _ a Null = pure a
2256−fromNull c _ v = prependContext c (typeMismatch "Null" v)
22571871
22581872instance FromJSON2 Tagged where
22591873 liftParseJSON2 _ _ p _ = fmap Tagged . p
@@ -2280,7 +1894,10 @@ instance (FromJSON a, FromJSON b, FromJSON c) => FromJSONKey (a,b,c)
22801894instance (FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSONKey (a,b,c,d)
22811895
22821896instance FromJSONKey Char where
2283− fromJSONKey = FromJSONKeyTextParser parseChar
1897+ fromJSONKey = FromJSONKeyTextParser $ \t ->
1898+ if T.length t == 1
1899+ then return (T.index t 0)
1900+ else typeMismatch "Expected Char but String didn't contain exactly one character" (String t)
22841901 fromJSONKeyList = FromJSONKeyText T.unpack
22851902
22861903instance (FromJSONKey a, FromJSON a) => FromJSONKey [a] where