@@ -5,19 +5,16 @@
5{-# LANGUAGE FlexibleInstances #-}
5{-# LANGUAGE FlexibleInstances #-}
6{-# LANGUAGE GADTs #-}
6{-# LANGUAGE GADTs #-}
7{-# LANGUAGE MultiParamTypeClasses #-}
7{-# LANGUAGE MultiParamTypeClasses #-}
8−{-# LANGUAGE NamedFieldPuns #-}
8+{-# LANGUAGE NoImplicitPrelude #-}
9{-# LANGUAGE OverloadedStrings #-}
9{-# LANGUAGE OverloadedStrings #-}
10+{-# LANGUAGE PolyKinds #-}
10{-# LANGUAGE RecordWildCards #-}
11{-# LANGUAGE RecordWildCards #-}
11{-# LANGUAGE ScopedTypeVariables #-}
12{-# LANGUAGE ScopedTypeVariables #-}
12{-# LANGUAGE TypeOperators #-}
13{-# LANGUAGE TypeOperators #-}
13−{-# LANGUAGE TypeSynonymInstances #-}
14+{-# LANGUAGE TupleSections #-}
14{-# LANGUAGE UndecidableInstances #-}
15{-# LANGUAGE UndecidableInstances #-}
15{-# LANGUAGE ViewPatterns #-}
16{-# LANGUAGE ViewPatterns #-}
17−#if __GLASGOW_HASKELL__ >= 706
18−{-# LANGUAGE PolyKinds #-}
21#include "incoherent-compat.h"
18#include "incoherent-compat.h"
22#include "overlapping-compat.h"
19#include "overlapping-compat.h"
@@ -45,6 +42,9 @@ module Data.Aeson.Types.FromJSON
45 , coerceFromJSONKeyFunction
42 , coerceFromJSONKeyFunction
46 , mapFromJSONKeyFunction
43 , mapFromJSONKeyFunction
48 -- * List functions
48 -- * List functions
49 , listParser
49 , listParser
@@ -52,34 +52,42 @@ module Data.Aeson.Types.FromJSON
52 , withObject
52 , withObject
53 , withText
53 , withText
54 , withArray
54 , withArray
56 , withScientific
55 , withScientific
57 , withBool
56 , withBool
59 -- * Functions
59 -- * Functions
60 , fromJSON
60 , fromJSON
61 , ifromJSON
61 , ifromJSON
68+ , explicitParseFieldMaybe
69+ , explicitParseFieldMaybe'
68 -- * Internal
77 -- * Internal
69 , parseOptionalFieldWith
78 , parseOptionalFieldWith
73import Prelude.Compat
81import Prelude.Compat
75−import Control.Applicative ((<|>), Const(..))
83+import Control.Applicative ((<|>), Const(..), liftA2)
76−import Control.Monad ((<=<), zipWithM)
84+import Control.Monad (zipWithM)
77import Data.Aeson.Internal.Functions (mapKey)
85import Data.Aeson.Internal.Functions (mapKey)
86+import Data.Aeson.Parser.Internal (eitherDecodeWith, jsonEOF)
78import Data.Aeson.Types.Generic
87import Data.Aeson.Types.Generic
79import Data.Aeson.Types.Internal
88import Data.Aeson.Types.Internal
80−import Data.Attoparsec.Number (Number(..))
81import Data.Bits (unsafeShiftR)
89import Data.Bits (unsafeShiftR)
82−import Data.Fixed (Fixed, HasResolution)
90+import Data.Fixed (Fixed, HasResolution (resolution), Nano)
83import Data.Functor.Compose (Compose(..))
91import Data.Functor.Compose (Compose(..))
84import Data.Functor.Identity (Identity(..))
92import Data.Functor.Identity (Identity(..))
85import Data.Functor.Product (Product(..))
93import Data.Functor.Product (Product(..))
@@ -88,26 +96,31 @@ import Data.Hashable (Hashable(..))
88import Data.Int (Int16, Int32, Int64, Int8)
96import Data.Int (Int16, Int32, Int64, Int8)
89import Data.List.NonEmpty (NonEmpty(..))
97import Data.List.NonEmpty (NonEmpty(..))
90import Data.Maybe (fromMaybe)
98import Data.Maybe (fromMaybe)
91−import Data.Monoid ((<>))
99+import Data.Semigroup ((<>))
92import Data.Proxy (Proxy(..))
100import Data.Proxy (Proxy(..))
93import Data.Ratio ((%), Ratio)
101import Data.Ratio ((%), Ratio)
94−import Data.Scientific (Scientific)
102+import Data.Scientific (Scientific, base10Exponent)
95import Data.Tagged (Tagged(..))
103import Data.Tagged (Tagged(..))
96import Data.Text (Text, pack, unpack)
104import Data.Text (Text, pack, unpack)
97−import Data.Time (Day, LocalTime, NominalDiffTime, TimeOfDay, UTCTime, ZonedTime)
105+import Data.Time (Day, DiffTime, LocalTime, NominalDiffTime, TimeOfDay, UTCTime, ZonedTime)
98−import Data.Time.Format (parseTime)
106+import Data.Time.Calendar.Compat (CalendarDiffDays (..), DayOfWeek (..))
107+import Data.Time.LocalTime.Compat (CalendarDiffTime (..))
108+import Data.Time.Clock.System.Compat (SystemTime (..))
99−import Data.Time.Locale.Compat (defaultTimeLocale)
109+import Data.Time.Format.Compat (parseTimeM, defaultTimeLocale)
100import Data.Traversable as Tr (sequence)
110import Data.Traversable as Tr (sequence)
101import Data.Vector (Vector)
111import Data.Vector (Vector)
102import Data.Version (Version, parseVersion)
112import Data.Version (Version, parseVersion)
113+import Data.Void (Void)
103import Data.Word (Word16, Word32, Word64, Word8)
114import Data.Word (Word16, Word32, Word64, Word8)
104import Foreign.Storable (Storable)
115import Foreign.Storable (Storable)
116+import Foreign.C.Types (CTime (..))
105import GHC.Generics
117import GHC.Generics
106import Numeric.Natural (Natural)
118import Numeric.Natural (Natural)
107import Text.ParserCombinators.ReadP (readP_to_S)
119import Text.ParserCombinators.ReadP (readP_to_S)
108import Unsafe.Coerce (unsafeCoerce)
120import Unsafe.Coerce (unsafeCoerce)
109import qualified Data.Aeson.Parser.Time as Time
121import qualified Data.Aeson.Parser.Time as Time
110import qualified Data.Attoparsec.ByteString.Char8 as A (endOfInput, parseOnly, scientific)
122import qualified Data.Attoparsec.ByteString.Char8 as A (endOfInput, parseOnly, scientific)
123+import qualified Data.ByteString.Lazy as L
111import qualified Data.DList as DList
124import qualified Data.DList as DList
112import qualified Data.HashMap.Strict as H
125import qualified Data.HashMap.Strict as H
113import qualified Data.HashSet as HashSet
126import qualified Data.HashSet as HashSet
@@ -123,24 +136,27 @@ import qualified Data.Text as T
123import qualified Data.Text.Encoding as T
136import qualified Data.Text.Encoding as T
124import qualified Data.Text.Lazy as LT
137import qualified Data.Text.Lazy as LT
125import qualified Data.Tree as Tree
138import qualified Data.Tree as Tree
139+import qualified Data.UUID.Types as UUID
126import qualified Data.Vector as V
140import qualified Data.Vector as V
127import qualified Data.Vector.Generic as VG
141import qualified Data.Vector.Generic as VG
128import qualified Data.Vector.Primitive as VP
142import qualified Data.Vector.Primitive as VP
129import qualified Data.Vector.Storable as VS
143import qualified Data.Vector.Storable as VS
130import qualified Data.Vector.Unboxed as VU
144import qualified Data.Vector.Unboxed as VU
132−#ifndef HAS_COERCIBLE
146+import qualified GHC.Exts as Exts
133−#define HAS_COERCIBLE (__GLASGOW_HASKELL__ >= 707)
147+import qualified Data.Primitive.Array as PM
148+import qualified Data.Primitive.SmallArray as PM
149+import qualified Data.Primitive.Types as PM
151+#if MIN_VERSION_primitive(0,6,4)
152+#if !MIN_VERSION_primitive(0,7,0)
153+import qualified Data.Primitive.UnliftedArray as PM
155+import qualified Data.Primitive.PrimArray as PM
136−#if HAS_COERCIBLE
158+
137import Data.Coerce (Coercible, coerce)
159import Data.Coerce (Coercible, coerce)
138−coerce' :: Coercible a b => a -> b
142−coerce' = unsafeCoerce
145parseIndexedJSON :: (Value -> Parser a) -> Int -> Value -> Parser a
161parseIndexedJSON :: (Value -> Parser a) -> Int -> Value -> Parser a
146parseIndexedJSON p idx value = p value <?> Index idx
162parseIndexedJSON p idx value = p value <?> Index idx
@@ -149,7 +165,7 @@ parseIndexedJSON p idx value = p value <?> Index idx
149parseIndexedJSONPair :: (Value -> Parser a) -> (Value -> Parser b) -> Int -> Value -> Parser (a, b)
165parseIndexedJSONPair :: (Value -> Parser a) -> (Value -> Parser b) -> Int -> Value -> Parser (a, b)
150parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
166parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
152− p = withArray "(k,v)" $ \ab ->
168+ p = withArray "(k, v)" $ \ab ->
153 let n = V.length ab
169 let n = V.length ab
154 in if n == 2
170 in if n == 2
155 then (,) <$> parseJSONElemAtIndex keyParser 0 ab
171 then (,) <$> parseJSONElemAtIndex keyParser 0 ab
@@ -161,43 +177,34 @@ parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
161parseJSONElemAtIndex :: (Value -> Parser a) -> Int -> V.Vector Value -> Parser a
177parseJSONElemAtIndex :: (Value -> Parser a) -> Int -> V.Vector Value -> Parser a
162parseJSONElemAtIndex p idx ary = p (V.unsafeIndex ary idx) <?> Index idx
178parseJSONElemAtIndex p idx ary = p (V.unsafeIndex ary idx) <?> Index idx
164−scientificToNumber :: Scientific -> Number
166− | e < 0 = D $ Scientific.toRealFloat s
167− | otherwise = I $ c * 10 ^ e
169− e = Scientific.base10Exponent s
170− c = Scientific.coefficient s
171−{-# INLINE scientificToNumber #-}
173parseRealFloat :: RealFloat a => String -> Value -> Parser a
180parseRealFloat :: RealFloat a => String -> Value -> Parser a
174−parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
181+parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
175−parseRealFloat _ Null = pure (0/0)
182+parseRealFloat _ Null = pure (0/0)
176−parseRealFloat expected v = typeMismatch expected v
183+parseRealFloat name v = prependContext name (unexpected v)
177{-# INLINE parseRealFloat #-}
184{-# INLINE parseRealFloat #-}
179−parseIntegralFromScientific :: forall a. Integral a => String -> Scientific -> Parser a
186+parseIntegralFromScientific :: forall a. Integral a => Scientific -> Parser a
180−parseIntegralFromScientific expected s =
187+parseIntegralFromScientific s =
181 case Scientific.floatingOrInteger s :: Either Double a of
188 case Scientific.floatingOrInteger s :: Either Double a of
182 Right x -> pure x
189 Right x -> pure x
183− Left _ -> fail $ "Floating number specified for " ++ expected ++ ": " ++ show s
190+ Left _ -> fail $ "unexpected floating number " ++ show s
184{-# INLINE parseIntegralFromScientific #-}
191{-# INLINE parseIntegralFromScientific #-}
186parseIntegral :: Integral a => String -> Value -> Parser a
193parseIntegral :: Integral a => String -> Value -> Parser a
187−parseIntegral expected =
194+parseIntegral name =
188− withScientific expected $ parseIntegralFromScientific expected
195+ prependContext name . withBoundedScientific' parseIntegralFromScientific
189{-# INLINE parseIntegral #-}
196{-# INLINE parseIntegral #-}
191−parseBoundedIntegralFromScientific :: (Bounded a, Integral a) => String -> Scientific -> Parser a
198+parseBoundedIntegralFromScientific :: (Bounded a, Integral a) => Scientific -> Parser a
192−parseBoundedIntegralFromScientific expected s = maybe
199+parseBoundedIntegralFromScientific s = maybe
193− (fail $ expected ++ " is either floating or will cause over or underflow: " ++ show s)
200+ (fail $ "value is either floating or will cause over or underflow " ++ show s)
195 (Scientific.toBoundedInteger s)
202 (Scientific.toBoundedInteger s)
196{-# INLINE parseBoundedIntegralFromScientific #-}
203{-# INLINE parseBoundedIntegralFromScientific #-}
198parseBoundedIntegral :: (Bounded a, Integral a) => String -> Value -> Parser a
205parseBoundedIntegral :: (Bounded a, Integral a) => String -> Value -> Parser a
199−parseBoundedIntegral expected =
206+parseBoundedIntegral name =
200− withScientific expected $ parseBoundedIntegralFromScientific expected
207+ prependContext name . withScientific' parseBoundedIntegralFromScientific
201{-# INLINE parseBoundedIntegral #-}
208{-# INLINE parseBoundedIntegral #-}
203parseScientificText :: Text -> Parser Scientific
210parseScientificText :: Text -> Parser Scientific
@@ -207,13 +214,20 @@ parseScientificText
207 . T.encodeUtf8
214 . T.encodeUtf8
209parseIntegralText :: Integral a => String -> Text -> Parser a
216parseIntegralText :: Integral a => String -> Text -> Parser a
210−parseIntegralText expected t =
217+parseIntegralText name t =
218+ prependContext name $
219+ parseScientificText t
220+ >>= rejectLargeExponent
211− parseScientificText t >>= parseIntegralFromScientific expected
221+ >>= parseIntegralFromScientific
223+ rejectLargeExponent :: Scientific -> Parser Scientific
224+ rejectLargeExponent s = withBoundedScientific' pure (Number s)
212{-# INLINE parseIntegralText #-}
225{-# INLINE parseIntegralText #-}
214parseBoundedIntegralText :: (Bounded a, Integral a) => String -> Text -> Parser a
227parseBoundedIntegralText :: (Bounded a, Integral a) => String -> Text -> Parser a
215−parseBoundedIntegralText expected t =
228+parseBoundedIntegralText name t =
229+ prependContext name $
216− parseScientificText t >>= parseBoundedIntegralFromScientific expected
230+ parseScientificText t >>= parseBoundedIntegralFromScientific
218parseOptionalFieldWith :: (Value -> Parser (Maybe a))
232parseOptionalFieldWith :: (Value -> Parser (Maybe a))
219 -> Object -> Text -> Parser (Maybe a)
233 -> Object -> Text -> Parser (Maybe a)
@@ -273,14 +287,21 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
274-- The basic ways to signal a failed conversion are as follows:
288-- The basic ways to signal a failed conversion are as follows:
290+-- * 'fail' yields a custom error message: it is the recommended way of
291+-- reporting a failure;
276−-- * 'empty' and 'mzero' work, but are terse and uninformative
293+-- * 'Control.Applicative.empty' (or 'Control.Monad.mzero') is uninformative:
294+-- use it when the error is meant to be caught by some @('<|>')@;
278−-- * 'fail' yields a custom error message
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
280−-- * 'typeMismatch' produces an informative message for cases when the
301+-- 'prependFailure' (or 'modifyFailure') add more information to a parser's
281−-- value encountered is not of the expected type
302+-- error messages.
283−-- An example type and instance:
304+-- An example type and instance using 'typeMismatch' and 'prependFailure':
286-- \-- Allow ourselves to write 'Text' literals.
307-- \-- Allow ourselves to write 'Text' literals.
@@ -288,15 +309,30 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
289-- data Coord = Coord { x :: Double, y :: Double }
310-- data Coord = Coord { x :: Double, y :: Double }
291−-- instance FromJSON Coord where
312+-- instance 'FromJSON' Coord where
292−-- parseJSON ('Object' v) = Coord '<$>'
313+-- 'parseJSON' ('Object' v) = Coord
293−-- v '.:' \"x\" '<*>'
314+-- '<$>' v '.:' \"x\"
294−-- v '.:' \"y\"
315+-- '<*>' v '.:' \"y\"
296−-- \-- We do not expect a non-'Object' value here.
317+-- \-- We do not expect a non-'Object' value here.
297−-- \-- We could use 'mzero' to fail, but 'typeMismatch'
318+-- \-- We could use 'Control.Applicative.empty' to fail, but 'typeMismatch'
298−-- \-- gives a much more informative error message.
319+-- \-- gives a much more informative error message.
320+-- 'parseJSON' invalid =
321+-- 'prependFailure' "parsing Coord failed, "
299−-- parseJSON invalid = 'typeMismatch' \"Coord\" invalid
322+-- ('typeMismatch' \"Object\" invalid)
325+-- For this common case of only being concerned with a single
326+-- type of JSON value, the functions 'withObject', 'withScientific', etc.
327+-- are provided. Their use is to be preferred when possible, since
328+-- they are more terse. Using 'withObject', we can rewrite the above instance
329+-- (assuming the same language extension and data type) as:
332+-- instance 'FromJSON' Coord where
333+-- 'parseJSON' = 'withObject' \"Coord\" $ \\v -> Coord
334+-- '<$>' v '.:' \"x\"
335+-- '<*>' v '.:' \"y\"
302-- Instead of manually writing your 'FromJSON' instance, there are two options
338-- Instead of manually writing your 'FromJSON' instance, there are two options
@@ -304,7 +340,7 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
305-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
341-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
306-- instance at compile time. The generated instance is optimized for your type
342-- instance at compile time. The generated instance is optimized for your type
307−-- so will probably be more efficient than the following two options:
343+-- so it will probably be more efficient than the following option.
309-- * The compiler can provide a default generic implementation for
345-- * The compiler can provide a default generic implementation for
310-- 'parseJSON'.
346-- 'parseJSON'.
@@ -322,18 +358,21 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
323-- data Coord = Coord { x :: Double, y :: Double } deriving 'Generic'
359-- data Coord = Coord { x :: Double, y :: Double } deriving 'Generic'
325−-- instance FromJSON Coord
361+-- instance 'FromJSON' Coord
328−-- If @DefaultSignatures@ doesn't give exactly the results you want,
364+-- The default implementation will be equivalent to
365+-- @parseJSON = 'genericParseJSON' 'defaultOptions'@; if you need different
329−-- you can customize the generic decoding with only a tiny amount of
366+-- options, you can customize the generic decoding by defining:
330−-- effort, using 'genericParseJSON' with your preferred 'Options':
369+-- customOptions = 'defaultOptions'
370+-- { 'fieldLabelModifier' = 'map' 'Data.Char.toUpper'
333−-- instance FromJSON Coord where
373+-- instance 'FromJSON' Coord where
334−-- parseJSON = 'genericParseJSON' 'defaultOptions'
374+-- 'parseJSON' = 'genericParseJSON' customOptions
337class FromJSON a where
376class FromJSON a where
338 parseJSON :: Value -> Parser a
377 parseJSON :: Value -> Parser a
@@ -341,13 +380,11 @@ class FromJSON a where
341 parseJSON = genericParseJSON defaultOptions
380 parseJSON = genericParseJSON defaultOptions
343 parseJSONList :: Value -> Parser [a]
382 parseJSONList :: Value -> Parser [a]
344− parseJSONList (Array a)
383+ parseJSONList = withArray "[]" $ \a ->
345− = zipWithM (parseIndexedJSON parseJSON) [0..]
384+ zipWithM (parseIndexedJSON parseJSON) [0..]
346 . V.toList
385 . V.toList
349− parseJSONList v = typeMismatch "[a]" v
351-------------------------------------------------------------------------------
388-------------------------------------------------------------------------------
352-- Classes and types for map keys
389-- Classes and types for map keys
353-------------------------------------------------------------------------------
390-------------------------------------------------------------------------------
@@ -359,6 +396,16 @@ class FromJSON a where
359-- > newtype SomeId = SomeId { getSomeId :: Text }
396-- > newtype SomeId = SomeId { getSomeId :: Text }
360-- > deriving (Eq,Ord,Hashable,FromJSONKey)
397-- > deriving (Eq,Ord,Hashable,FromJSONKey)
399+-- If you have a sum of nullary constructors, you may use the generic
403+-- data Color = Red | Green | Blue
406+-- instance 'FromJSONKey' Color where
407+-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
362class FromJSONKey a where
409class FromJSONKey a where
363 -- | Strategy for parsing the key of a map-like container.
410 -- | Strategy for parsing the key of a map-like container.
364 fromJSONKey :: FromJSONKeyFunction a
411 fromJSONKey :: FromJSONKeyFunction a
@@ -381,11 +428,7 @@ class FromJSONKey a where
381-- At the moment this type is intentionally not exported. 'FromJSONKeyFunction'
428-- At the moment this type is intentionally not exported. 'FromJSONKeyFunction'
382-- can be inspected, but cannot be constructed.
429-- can be inspected, but cannot be constructed.
383data CoerceText a where
430data CoerceText a where
385 CoerceText :: Coercible Text a => CoerceText a
431 CoerceText :: Coercible Text a => CoerceText a
387− CoerceText :: CoerceText a
390-- | This type is related to 'ToJSONKeyFunction'. If 'FromJSONKeyValue' is used in the
433-- | This type is related to 'ToJSONKeyFunction'. If 'FromJSONKeyValue' is used in the
391-- 'FromJSONKey' instance, then 'ToJSONKeyValue' should be used in the 'ToJSONKey'
434-- 'FromJSONKey' instance, then 'ToJSONKeyValue' should be used in the 'ToJSONKey'
@@ -405,7 +448,7 @@ data FromJSONKeyFunction a
406-- | Only law abiding up to interpretation
449-- | Only law abiding up to interpretation
407instance Functor FromJSONKeyFunction where
450instance Functor FromJSONKeyFunction where
408− fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce')
451+ fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce)
409 fmap h (FromJSONKeyText f) = FromJSONKeyText (h . f)
452 fmap h (FromJSONKeyText f) = FromJSONKeyText (h . f)
410 fmap h (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap h . f)
453 fmap h (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap h . f)
411 fmap h (FromJSONKeyValue f) = FromJSONKeyValue (fmap h . f)
454 fmap h (FromJSONKeyValue f) = FromJSONKeyValue (fmap h . f)
@@ -419,9 +462,7 @@ instance Functor FromJSONKeyFunction where
420-- On pre GHC 7.8 this is unconstrainted function.
463-- On pre GHC 7.8 this is unconstrainted function.
421fromJSONKeyCoerce ::
464fromJSONKeyCoerce ::
423 Coercible Text a =>
465 Coercible Text a =>
425 FromJSONKeyFunction a
466 FromJSONKeyFunction a
426fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
467fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
@@ -429,60 +470,91 @@ fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
430-- See note on 'fromJSONKeyCoerce'.
471-- See note on 'fromJSONKeyCoerce'.
431coerceFromJSONKeyFunction ::
472coerceFromJSONKeyFunction ::
433 Coercible a b =>
473 Coercible a b =>
435 FromJSONKeyFunction a -> FromJSONKeyFunction b
474 FromJSONKeyFunction a -> FromJSONKeyFunction b
437coerceFromJSONKeyFunction = coerce
475coerceFromJSONKeyFunction = coerce
439−coerceFromJSONKeyFunction (FromJSONKeyCoerce CoerceText) = FromJSONKeyCoerce CoerceText
440−coerceFromJSONKeyFunction (FromJSONKeyText f) = FromJSONKeyText (coerce' . f)
441−coerceFromJSONKeyFunction (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap coerce' . f)
442−coerceFromJSONKeyFunction (FromJSONKeyValue f) = FromJSONKeyValue (fmap coerce' . f)
446 "FromJSONKeyCoerce: fmap id" forall (x :: FromJSONKeyFunction a).
478 "FromJSONKeyCoerce: fmap id" forall (x :: FromJSONKeyFunction a).
447 fmap id x = x
479 fmap id x = x
451 "FromJSONKeyCoerce: fmap coerce" forall x .
482 "FromJSONKeyCoerce: fmap coerce" forall x .
452 fmap coerce x = coerceFromJSONKeyFunction x
483 fmap coerce x = coerceFromJSONKeyFunction x
456-- | Same as 'fmap'. Provided for the consistency with 'ToJSONKeyFunction'.
486-- | Same as 'fmap'. Provided for the consistency with 'ToJSONKeyFunction'.
457mapFromJSONKeyFunction :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b
487mapFromJSONKeyFunction :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b
458mapFromJSONKeyFunction = fmap
488mapFromJSONKeyFunction = fmap
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.
494+-- See also 'genericToJSONKey'.
499+-- data Color = Red | Green | Blue
500+-- deriving 'Generic'
502+-- instance 'FromJSONKey' Color where
503+-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
505+genericFromJSONKey :: forall a. (Generic a, GFromJSONKey (Rep a))
507+ -> FromJSONKeyFunction a
508+genericFromJSONKey opts = FromJSONKeyTextParser $ \t ->
509+ case parseSumFromString (keyModifier opts) t of
511+ "invalid key " ++ show t ++ ", expected one of " ++ show cnames
512+ Just k -> pure (to k)
514+ cnames = unTagged2 (constructorTags (keyModifier opts) :: Tagged2 (Rep a) [String])
516+class (ConstructorNames f, SumFromString f) => GFromJSONKey f where
517+instance (ConstructorNames f, SumFromString f) => GFromJSONKey f where
460-------------------------------------------------------------------------------
519-------------------------------------------------------------------------------
461-- Functions needed for documentation
520-- Functions needed for documentation
462-------------------------------------------------------------------------------
521-------------------------------------------------------------------------------
464-- | Fail parsing due to a type mismatch, with a descriptive message.
523-- | Fail parsing due to a type mismatch, with a descriptive message.
466−-- Example usage:
525+-- The following wrappers should generally be prefered:
526+-- 'withObject', 'withArray', 'withText', 'withBool'.
468−-- @
528+-- ==== Error message example
469−-- instance FromJSON Coord where
529+--
470−-- parseJSON ('Object' v) = {- type matches, life is good -}
530+-- > typeMismatch "Object" (String "oops")
471−-- parseJSON wat = 'typeMismatch' \"Coord\" wat
531+-- > -- Error: "expected Object, but encountered String"
473−typeMismatch :: String -- ^ The name of the type you are trying to parse.
532+typeMismatch :: String -- ^ The name of the JSON type being parsed
533+ -- (@\"Object\"@, @\"Array\"@, @\"String\"@, @\"Number\"@,
534+ -- @\"Boolean\"@, or @\"Null\"@).
474 -> Value -- ^ The actual value encountered.
535 -> Value -- ^ The actual value encountered.
475 -> Parser a
536 -> Parser a
476typeMismatch expected actual =
537typeMismatch expected actual =
477− fail $ "expected " ++ expected ++ ", encountered " ++ name
538+ fail $ "expected " ++ expected ++ ", but encountered " ++ typeOf actual
540+-- | Fail parsing due to a type mismatch, when the expected types are implicit.
542+-- ==== Error message example
544+-- > unexpected (String "oops")
545+-- > -- Error: "unexpected String"
546+unexpected :: Value -> Parser a
547+unexpected actual = fail $ "unexpected " ++ typeOf actual
549+-- | JSON type of a value, name of the head constructor.
550+typeOf :: Value -> String
479− name = case actual of
551+typeOf v = case v of
480− Object _ -> "Object"
552+ Object _ -> "Object"
481− Array _ -> "Array"
553+ Array _ -> "Array"
482− String _ -> "String"
554+ String _ -> "String"
483− Number _ -> "Number"
555+ Number _ -> "Number"
484− Bool _ -> "Boolean"
556+ Bool _ -> "Boolean"
485− Null -> "Null"
557+ Null -> "Null"
487-------------------------------------------------------------------------------
559-------------------------------------------------------------------------------
488-- Lifings of FromJSON and ToJSON to unary and binary type constructors
560-- Lifings of FromJSON and ToJSON to unary and binary type constructors
@@ -495,7 +567,7 @@ typeMismatch expected actual =
496-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
568-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
497-- instance at compile time. The generated instance is optimized for your type
569-- instance at compile time. The generated instance is optimized for your type
498−-- so will probably be more efficient than the following two options:
570+-- so it will probably be more efficient than the following option.
500-- * The compiler can provide a default generic implementation for
572-- * The compiler can provide a default generic implementation for
501-- 'liftParseJSON'.
573-- 'liftParseJSON'.
@@ -513,16 +585,20 @@ typeMismatch expected actual =
514-- data Pair a b = Pair { pairFst :: a, pairSnd :: b } deriving 'Generic1'
586-- data Pair a b = Pair { pairFst :: a, pairSnd :: b } deriving 'Generic1'
516−-- instance FromJSON a => FromJSON1 (Pair a)
588+-- instance 'FromJSON' a => 'FromJSON1' (Pair a)
519−-- If @DefaultSignatures@ doesn't give exactly the results you want,
591+-- If the default implementation doesn't give exactly the results you want,
520-- you can customize the generic decoding with only a tiny amount of
592-- you can customize the generic decoding with only a tiny amount of
521-- effort, using 'genericLiftParseJSON' with your preferred 'Options':
593-- effort, using 'genericLiftParseJSON' with your preferred 'Options':
596+-- customOptions = 'defaultOptions'
597+-- { 'fieldLabelModifier' = 'map' 'Data.Char.toUpper'
524−-- instance FromJSON a => FromJSON1 (Pair a) where
600+-- instance 'FromJSON' a => 'FromJSON1' (Pair a) where
525−-- liftParseJSON = 'genericLiftParseJSON' 'defaultOptions'
601+-- 'liftParseJSON' = 'genericLiftParseJSON' customOptions
527class FromJSON1 f where
603class FromJSON1 f where
528 liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (f a)
604 liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (f a)
@@ -559,9 +635,8 @@ class FromJSON2 f where
559 -> (Value -> Parser b)
635 -> (Value -> Parser b)
560 -> (Value -> Parser [b])
636 -> (Value -> Parser [b])
561 -> Value -> Parser [f a b]
637 -> Value -> Parser [f a b]
562− liftParseJSONList2 fa ga fb gb v = case v of
638+ liftParseJSONList2 fa ga fb gb = withArray "[]" $ \vals ->
563− Array vals -> fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
639+ fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
564− _ -> typeMismatch "[a]" v
566-- | Lift the standard 'parseJSON' function through the type constructor.
641-- | Lift the standard 'parseJSON' function through the type constructor.
567parseJSON2 :: (FromJSON2 f, FromJSON a, FromJSON b) => Value -> Parser (f a b)
642parseJSON2 :: (FromJSON2 f, FromJSON a, FromJSON b) => Value -> Parser (f a b)
@@ -575,7 +650,7 @@ parseJSON2 = liftParseJSON2 parseJSON parseJSONList parseJSON parseJSONList
575-- | Helper function to use with 'liftParseJSON'. See 'Data.Aeson.ToJSON.listEncoding'.
650-- | Helper function to use with 'liftParseJSON'. See 'Data.Aeson.ToJSON.listEncoding'.
576listParser :: (Value -> Parser a) -> Value -> Parser [a]
651listParser :: (Value -> Parser a) -> Value -> Parser [a]
577listParser f (Array xs) = fmap V.toList (V.mapM f xs)
652listParser f (Array xs) = fmap V.toList (V.mapM f xs)
578−listParser _ v = typeMismatch "[a]" v
653+listParser _ v = typeMismatch "Array" v
579{-# INLINE listParser #-}
654{-# INLINE listParser #-}
581-------------------------------------------------------------------------------
656-------------------------------------------------------------------------------
@@ -593,48 +668,139 @@ instance (FromJSON a) => FromJSON [a] where
593-- Functions
668-- Functions
594-------------------------------------------------------------------------------
669-------------------------------------------------------------------------------
671+-- | Add context to a failure message, indicating the name of the structure
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, ")
596−-- | @withObject expected f value@ applies @f@ to the 'Object' when @value@ is an @Object@
679+-- | @'withObject' name f value@ applies @f@ to the 'Object' when @value@
597−-- and fails using @'typeMismatch' expected@ otherwise.
680+-- is an 'Data.Aeson.Object' and fails otherwise.
682+-- ==== Error message example
684+-- > withObject "MyType" f (String "oops")
685+-- > -- Error: "parsing MyType failed, expected Object, but encountered String"
598withObject :: String -> (Object -> Parser a) -> Value -> Parser a
686withObject :: String -> (Object -> Parser a) -> Value -> Parser a
599−withObject _ f (Object obj) = f obj
687+withObject _ f (Object obj) = f obj
600−withObject expected _ v = typeMismatch expected v
688+withObject name _ v = prependContext name (typeMismatch "Object" v)
601{-# INLINE withObject #-}
689{-# INLINE withObject #-}
603−-- | @withText expected f value@ applies @f@ to the 'Text' when @value@ is a @String@
691+-- | @'withText' name f value@ applies @f@ to the 'Text' when @value@ is a
604−-- and fails using @'typeMismatch' expected@ otherwise.
692+-- 'Data.Aeson.String' and fails otherwise.
694+-- ==== Error message example
696+-- > withText "MyType" f Null
697+-- > -- Error: "parsing MyType failed, expected String, but encountered Null"
605withText :: String -> (Text -> Parser a) -> Value -> Parser a
698withText :: String -> (Text -> Parser a) -> Value -> Parser a
606−withText _ f (String txt) = f txt
699+withText _ f (String txt) = f txt
607−withText expected _ v = typeMismatch expected v
700+withText name _ v = prependContext name (typeMismatch "String" v)
608{-# INLINE withText #-}
701{-# INLINE withText #-}
610−-- | @withArray expected f value@ applies @f@ to the 'Array' when @value@ is an @Array@
703+-- | @'withArray' expected f value@ applies @f@ to the 'Array' when @value@ is
611−-- and fails using @'typeMismatch' expected@ otherwise.
704+-- an 'Data.Aeson.Array' and fails otherwise.
706+-- ==== Error message example
708+-- > withArray "MyType" f (String "oops")
709+-- > -- Error: "parsing MyType failed, expected Array, but encountered String"
612withArray :: String -> (Array -> Parser a) -> Value -> Parser a
710withArray :: String -> (Array -> Parser a) -> Value -> Parser a
613−withArray _ f (Array arr) = f arr
711+withArray _ f (Array arr) = f arr
614−withArray expected _ v = typeMismatch expected v
712+withArray name _ v = prependContext name (typeMismatch "Array" v)
615{-# INLINE withArray #-}
713{-# INLINE withArray #-}
617−-- | @withNumber expected f value@ applies @f@ to the 'Number' when @value@ is a 'Number'.
618−-- and fails using @'typeMismatch' expected@ otherwise.
619−withNumber :: String -> (Number -> Parser a) -> Value -> Parser a
620−withNumber expected f = withScientific expected (f . scientificToNumber)
621−{-# INLINE withNumber #-}
622−{-# DEPRECATED withNumber "Use withScientific instead" #-}
624−-- | @withScientific expected f value@ applies @f@ to the 'Scientific' number when @value@ is a 'Number'.
715+-- | @'withScientific' name f value@ applies @f@ to the 'Scientific' number
625−-- and fails using @'typeMismatch' expected@ otherwise.
716+-- when @value@ is a 'Data.Aeson.Number' and fails using 'typeMismatch'
719+-- /Warning/: If you are converting from a scientific to an unbounded
720+-- type such as 'Integer' you may want to add a restriction on the
721+-- size of the exponent (see 'withBoundedScientific') to prevent
722+-- malicious input from filling up the memory of the target system.
724+-- ==== Error message example
726+-- > withScientific "MyType" f (String "oops")
727+-- > -- Error: "parsing MyType failed, expected Number, but encountered String"
626withScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
728withScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
627−withScientific _ f (Number scientific) = f scientific
729+withScientific _ f (Number scientific) = f scientific
628−withScientific expected _ v = typeMismatch expected v
730+withScientific name _ v = prependContext name (typeMismatch "Number" v)
629{-# INLINE withScientific #-}
731{-# INLINE withScientific #-}
631−-- | @withBool expected f value@ applies @f@ to the 'Bool' when @value@ is a @Bool@
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.
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.
742+-- ==== Error message examples
744+-- > withScientific' f (String "oops")
745+-- > -- Error: "unexpected String"
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
752+ _ -> typeMismatch "Number" v
753+{-# INLINE withScientific' #-}
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.
757+withBoundedScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
758+withBoundedScientific name f v = withBoundedScientific_ (prependContext name) f v
759+{-# INLINE withBoundedScientific #-}
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' #-}
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) =
773+ then whenFail (fail msg)
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_ #-}
782+-- | @'withBool' expected f value@ applies @f@ to the 'Bool' when @value@ is a
632−-- and fails using @'typeMismatch' expected@ otherwise.
783+-- 'Boolean' and fails otherwise.
785+-- ==== Error message example
787+-- > withBool "MyType" f (String "oops")
788+-- > -- Error: "parsing MyType failed, expected Boolean, but encountered String"
633withBool :: String -> (Bool -> Parser a) -> Value -> Parser a
789withBool :: String -> (Bool -> Parser a) -> Value -> Parser a
634−withBool _ f (Bool arr) = f arr
790+withBool _ f (Bool arr) = f arr
635−withBool expected _ v = typeMismatch expected v
791+withBool name _ v = prependContext name (typeMismatch "Boolean" v)
636{-# INLINE withBool #-}
792{-# INLINE withBool #-}
794+-- | Decode a nested JSON-encoded string.
795+withEmbeddedJSON :: String -> (Value -> Parser a) -> Value -> Parser a
796+withEmbeddedJSON _ innerParser (String txt) =
797+ either fail innerParser $ eitherDecode (L.fromStrict $ T.encodeUtf8 txt)
799+ eitherDecode = eitherFormatError . eitherDecodeWith jsonEOF ifromJSON
800+ eitherFormatError = either (Left . uncurry formatError) Right
801+withEmbeddedJSON name _ v = prependContext name (typeMismatch "String" v)
802+{-# INLINE withEmbeddedJSON #-}
638-- | Convert a value from JSON, failing if the types do not match.
804-- | Convert a value from JSON, failing if the types do not match.
639fromJSON :: (FromJSON a) => Value -> Result a
805fromJSON :: (FromJSON a) => Value -> Result a
640fromJSON = parse parseJSON
806fromJSON = parse parseJSON
@@ -653,9 +819,7 @@ ifromJSON = iparse parseJSON
653-- in an object for it to be valid. If the key and value are
819-- in an object for it to be valid. If the key and value are
654-- optional, use '.:?' instead.
820-- optional, use '.:?' instead.
655(.:) :: (FromJSON a) => Object -> Text -> Parser a
821(.:) :: (FromJSON a) => Object -> Text -> Parser a
656−obj .: key = case H.lookup key obj of
822+(.:) = explicitParseField parseJSON
657− Nothing -> fail $ "key " ++ show key ++ " not present"
658− Just v -> parseJSON v <?> Key key
659{-# INLINE (.:) #-}
823{-# INLINE (.:) #-}
661-- | Retrieve the value associated with the given key of an 'Object'. The
825-- | Retrieve the value associated with the given key of an 'Object'. The
@@ -666,9 +830,7 @@ obj .: key = case H.lookup key obj of
666-- from an object without affecting its validity. If the key and
830-- from an object without affecting its validity. If the key and
667-- value are mandatory, use '.:' instead.
831-- value are mandatory, use '.:' instead.
668(.:?) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
832(.:?) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
669−obj .:? key = case H.lookup key obj of
833+(.:?) = explicitParseFieldMaybe parseJSON
670− Nothing -> pure Nothing
671− Just v -> parseJSON v <?> Key key
672{-# INLINE (.:?) #-}
834{-# INLINE (.:?) #-}
674-- | Retrieve the value associated with the given key of an 'Object'.
836-- | Retrieve the value associated with the given key of an 'Object'.
@@ -678,11 +840,47 @@ obj .:? key = case H.lookup key obj of
678-- This differs from '.:?' by attempting to parse 'Null' the same as any
840-- This differs from '.:?' by attempting to parse 'Null' the same as any
679-- other JSON value, instead of interpreting it as 'Nothing'.
841-- other JSON value, instead of interpreting it as 'Nothing'.
680(.:!) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
842(.:!) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
681−obj .:! key = case H.lookup key obj of
843+(.:!) = explicitParseFieldMaybe' parseJSON
682− Nothing -> pure Nothing
683− Just v -> Just <$> parseJSON v <?> Key key
684{-# INLINE (.:!) #-}
844{-# INLINE (.:!) #-}
846+-- | Function variant of '.:'.
847+parseField :: (FromJSON a) => Object -> Text -> Parser a
849+{-# INLINE parseField #-}
851+-- | Function variant of '.:?'.
852+parseFieldMaybe :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
853+parseFieldMaybe = (.:?)
854+{-# INLINE parseFieldMaybe #-}
856+-- | Function variant of '.:!'.
857+parseFieldMaybe' :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
858+parseFieldMaybe' = (.:!)
859+{-# INLINE parseFieldMaybe' #-}
861+-- | Variant of '.:' with explicit parser function.
863+-- E.g. @'explicitParseField' 'parseJSON1' :: ('FromJSON1' f, 'FromJSON' a) -> 'Object' -> 'Text' -> 'Parser' (f a)@
864+explicitParseField :: (Value -> Parser a) -> Object -> Text -> Parser a
865+explicitParseField p obj key = case H.lookup key obj of
866+ Nothing -> fail $ "key " ++ show key ++ " not found"
867+ Just v -> p v <?> Key key
868+{-# INLINE explicitParseField #-}
870+-- | Variant of '.:?' with explicit parser function.
871+explicitParseFieldMaybe :: (Value -> Parser a) -> Object -> Text -> Parser (Maybe a)
872+explicitParseFieldMaybe p obj key = case H.lookup key obj of
873+ Nothing -> pure Nothing
874+ Just v -> liftParseJSON p (listParser p) v <?> Key key -- listParser isn't used by maybe instance.
875+{-# INLINE explicitParseFieldMaybe #-}
877+-- | Variant of '.:!' with explicit parser function.
878+explicitParseFieldMaybe' :: (Value -> Parser a) -> Object -> Text -> Parser (Maybe a)
879+explicitParseFieldMaybe' p obj key = case H.lookup key obj of
880+ Nothing -> pure Nothing
881+ Just v -> Just <$> p v <?> Key key
882+{-# INLINE explicitParseFieldMaybe' #-}
686-- | Helper for use in combination with '.:?' to provide default
884-- | Helper for use in combination with '.:?' to provide default
687-- values for optional JSON object fields.
885-- values for optional JSON object fields.
@@ -705,11 +903,47 @@ pmval .!= val = fromMaybe val <$> pmval
705-- Generic parseJSON
903-- Generic parseJSON
706-------------------------------------------------------------------------------
904-------------------------------------------------------------------------------
906+instance GFromJSON arity V1 where
907+ -- Whereof we cannot format, thereof we cannot parse:
908+ gParseJSON _ _ _ = fail "Attempted to parse empty type"
708instance OVERLAPPABLE_ (GFromJSON arity a) => GFromJSON arity (M1 i c a) where
911instance OVERLAPPABLE_ (GFromJSON arity a) => GFromJSON arity (M1 i c a) where
709 -- Meta-information, which is not handled elsewhere, is just added to the
912 -- Meta-information, which is not handled elsewhere, is just added to the
710 -- parsed value:
913 -- parsed value:
711 gParseJSON opts fargs = fmap M1 . gParseJSON opts fargs
914 gParseJSON opts fargs = fmap M1 . gParseJSON opts fargs
916+-- Information for error messages
918+type TypeName = String
919+type ConName = String
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
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 ++ ", ")
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)
939+-- | Render a constructor as @\"MyType(MyConstructor)\"@.
940+showCons :: ConName -> TypeName -> String
941+showCons cname tname = tname ++ "(" ++ cname ++ ")"
943+--------------------------------------------------------------------------------
945+-- Parsing single fields
713instance (FromJSON a) => GFromJSON arity (K1 i a) where
947instance (FromJSON a) => GFromJSON arity (K1 i a) where
714 -- Constant values are decoded using their FromJSON instance:
948 -- Constant values are decoded using their FromJSON instance:
715 gParseJSON _opts _ = fmap K1 . parseJSON
949 gParseJSON _opts _ = fmap K1 . parseJSON
@@ -724,326 +958,499 @@ instance (FromJSON1 f) => GFromJSON One (Rec1 f) where
724 -- FromJSON1 instance:
958 -- FromJSON1 instance:
725 gParseJSON _opts (From1Args pj pjl) = fmap Rec1 . liftParseJSON pj pjl
959 gParseJSON _opts (From1Args pj pjl) = fmap Rec1 . liftParseJSON pj pjl
727−instance GFromJSON arity U1 where
728− -- Empty constructors are expected to be encoded as an empty array:
729− gParseJSON _opts _ v
730− | isEmptyArray v = pure U1
731− | otherwise = typeMismatch "unit constructor (U1)" v
733−instance (ConsFromJSON arity a) => GFromJSON arity (C1 c a) where
734− -- Constructors need to be decoded differently depending on whether they're
735− -- a record or not. This distinction is made by consParseJSON:
736− gParseJSON opts fargs = fmap M1 . consParseJSON opts fargs
738−instance ( FromProduct arity a, FromProduct arity b
739− , ProductSize a, ProductSize b
740− ) => GFromJSON arity (a :*: b) where
741− -- Products are expected to be encoded to an array. Here we check whether we
742− -- got an array of the same size as the product, then parse each of the
743− -- product's elements using parseProduct:
744− gParseJSON opts fargs = withArray "product (:*:)" $ \arr ->
745− let lenArray = V.length arr
746− lenProduct = (unTagged2 :: Tagged2 (a :*: b) Int -> Int)
748− if lenArray == lenProduct
749− then parseProduct opts fargs arr 0 lenProduct
750− else fail $ "When expecting a product of " ++ show lenProduct ++
751− " values, encountered an Array of " ++ show lenArray ++
754−instance ( AllNullary (a :+: b) allNullary
755− , ParseSum arity (a :+: b) allNullary
756− ) => GFromJSON arity (a :+: b) where
757− -- If all constructors of a sum datatype are nullary and the
758− -- 'allNullaryToStringTag' option is set they are expected to be
759− -- encoded as strings. This distinction is made by 'parseSum':
760− gParseJSON opts fargs =
761− (unTagged :: Tagged allNullary (Parser ((a :+: b) d)) ->
762− Parser ((a :+: b) d))
763− . parseSum opts fargs
765instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
961instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
766 -- If an occurrence of the last type parameter is nested inside two
962 -- If an occurrence of the last type parameter is nested inside two
767 -- composed types, it is decoded by using the outermost type's FromJSON1
963 -- composed types, it is decoded by using the outermost type's FromJSON1
768 -- instance to generically decode the innermost type:
964 -- instance to generically decode the innermost type:
769 gParseJSON opts fargs =
965 gParseJSON opts fargs =
770− let gpj = gParseJSON opts fargs in
966+ let gpj = gParseJSON opts fargs in
771− fmap Comp1 . liftParseJSON gpj (listParser gpj)
967+ fmap Comp1 . liftParseJSON gpj (listParser gpj)
969+--------------------------------------------------------------------------------
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
974+ gParseJSON opts fargs = fmap M1 . gParseJSON' (tname :* opts :* fargs)
976+ tname = moduleName proxy ++ "." ++ datatypeName proxy
977+ proxy = undefined :: M1 _i d _f _p
979+-- | 'GFromJSON', after unwrapping the 'D1' constructor, now carrying the data
981+class GFromJSON' arity f where
982+ gParseJSON' :: TypeName :* Options :* FromArgs arity a
986+-- | Single constructor.
987+instance ( ConsFromJSON arity a
988+ , AllNullary (C1 c a) allNullary
989+ , ParseSum arity (C1 c a) allNullary
991+ ) => GFromJSON' arity (C1 c a) where
992+ -- The option 'tagSingleConstructors' determines whether to wrap
993+ -- a single-constructor type.
994+ gParseJSON' p@(_ :* opts :* _)
995+ | tagSingleConstructors opts
996+ = (unTagged :: Tagged allNullary (Parser (C1 c a p)) -> Parser (C1 c a p))
998+ | otherwise = fmap M1 . consParseJSON (cname :* p)
1000+ cname = conName (undefined :: M1 _i c _f _p)
1002+-- | Multiple constructors.
1003+instance ( AllNullary (a :+: b) allNullary
1004+ , ParseSum arity (a :+: b) allNullary
1005+ ) => GFromJSON' arity (a :+: b) where
1006+ -- If all constructors of a sum datatype are nullary and the
1007+ -- 'allNullaryToStringTag' option is set they are expected to be
1008+ -- encoded as strings. This distinction is made by 'parseSum':
1010+ (unTagged :: Tagged allNullary (Parser ((a :+: b) _d)) ->
1011+ Parser ((a :+: b) _d))
773--------------------------------------------------------------------------------
1014--------------------------------------------------------------------------------
775class ParseSum arity f allNullary where
1016class ParseSum arity f allNullary where
776− parseSum :: Options -> FromArgs arity a
1017+ parseSum :: TypeName :* Options :* FromArgs arity a
777− -> Value -> Tagged allNullary (Parser (f a))
1019+ -> Tagged allNullary (Parser (f a))
1021+instance ( ConstructorNames f
779−instance ( SumFromString (a :+: b)
1022+ , SumFromString f
780− , FromPair arity (a :+: b)
1023+ , FromPair arity f
781− , FromTaggedObject arity (a :+: b)
1024+ , FromTaggedObject arity f
782− , FromUntaggedValue arity (a :+: b)
1025+ , FromUntaggedValue arity f
783− ) => ParseSum arity (a :+: b) True where
1026+ ) => ParseSum arity f True where
784− parseSum opts fargs
1027+ parseSum p@(tname :* opts :* _)
785− | allNullaryToStringTag opts = Tagged . parseAllNullarySum opts
1028+ | allNullaryToStringTag opts = Tagged . parseAllNullarySum tname opts
786− | otherwise = Tagged . parseNonAllNullarySum opts fargs
1029+ | otherwise = Tagged . parseNonAllNullarySum p
1031+instance ( ConstructorNames f
788−instance ( FromPair arity (a :+: b)
1032+ , FromPair arity f
789− , FromTaggedObject arity (a :+: b)
1033+ , FromTaggedObject arity f
790− , FromUntaggedValue arity (a :+: b)
1034+ , FromUntaggedValue arity f
791− ) => ParseSum arity (a :+: b) False where
1035+ ) => ParseSum arity f False where
792− parseSum opts fargs = Tagged . parseNonAllNullarySum opts fargs
1036+ parseSum p = Tagged . parseNonAllNullarySum p
794--------------------------------------------------------------------------------
1038--------------------------------------------------------------------------------
796−parseAllNullarySum :: SumFromString f => Options -> Value -> Parser (f a)
1040+parseAllNullarySum :: (SumFromString f, ConstructorNames f)
1041+ => TypeName -> Options -> Value -> Parser (f a)
797−parseAllNullarySum opts = withText "Text" $ \key ->
1042+parseAllNullarySum tname opts =
1043+ withText tname $ \tag ->
798− maybe (notFound key) return $
1044+ maybe (badTag tag) return $
799− parseSumFromString opts key
1045+ parseSumFromString modifier tag
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
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.
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
1061+ cnames = unTagged2 (constructorTags modifier :: Tagged2 f [t])
801class SumFromString f where
1063class SumFromString f where
802− parseSumFromString :: Options -> Text -> Maybe (f a)
1064+ parseSumFromString :: (String -> String) -> Text -> Maybe (f a)
804instance (SumFromString a, SumFromString b) => SumFromString (a :+: b) where
1066instance (SumFromString a, SumFromString b) => SumFromString (a :+: b) where
805 parseSumFromString opts key = (L1 <$> parseSumFromString opts key) <|>
1067 parseSumFromString opts key = (L1 <$> parseSumFromString opts key) <|>
806 (R1 <$> parseSumFromString opts key)
1068 (R1 <$> parseSumFromString opts key)
808instance (Constructor c) => SumFromString (C1 c U1) where
1070instance (Constructor c) => SumFromString (C1 c U1) where
809− parseSumFromString opts key | key == name = Just $ M1 U1
1071+ parseSumFromString modifier key
1072+ | key == name = Just $ M1 U1
810− | otherwise = Nothing
1073+ | otherwise = Nothing
812− name = pack $ constructorTagModifier opts $
813− conName (undefined :: t c U1 p)
1075+ name = pack $ modifier $ conName (undefined :: M1 _i c _f _p)
815−--------------------------------------------------------------------------------
1077+-- For genericFromJSONKey
1078+instance SumFromString a => SumFromString (D1 d a) where
1079+ parseSumFromString modifier key = M1 <$> parseSumFromString modifier key
1081+-- | List of all constructor tags.
1082+constructorTags :: ConstructorNames a => (String -> t) -> Tagged2 a [t]
1083+constructorTags modifier =
1084+ fmap DList.toList (constructorNames' modifier)
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)
1091+instance (ConstructorNames a, ConstructorNames b) => ConstructorNames (a :+: b) where
1092+ constructorNames' = liftA2 append constructorNames' constructorNames'
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)
1100+instance Constructor c => ConstructorNames (C1 c a) where
1101+ constructorNames' f = Tagged2 (pure (f cname))
1103+ cname = conName (undefined :: M1 _i c _f _p)
1105+-- For genericFromJSONKey
1106+instance ConstructorNames a => ConstructorNames (D1 d a) where
1107+ constructorNames' = retag . constructorNames'
1109+ retag :: Tagged2 a u -> Tagged2 (D1 d a) u
1110+ retag (Tagged2 x) = Tagged2 x
1112+--------------------------------------------------------------------------------
817−parseNonAllNullarySum :: ( FromPair arity (a :+: b)
1113+parseNonAllNullarySum :: forall f c arity.
818− , FromTaggedObject arity (a :+: b)
1115+ , FromTaggedObject arity f
819− , FromUntaggedValue arity (a :+: b)
1116+ , FromUntaggedValue arity f
1117+ , ConstructorNames f
820− ) => Options -> FromArgs arity c
1118+ ) => TypeName :* Options :* FromArgs arity c
821− -> Value -> Parser ((a :+: b) c)
1119+ -> Value -> Parser (f c)
822−parseNonAllNullarySum opts fargs =
1120+parseNonAllNullarySum p@(tname :* opts :* _) =
823 case sumEncoding opts of
1121 case sumEncoding opts of
824 TaggedObject{..} ->
1122 TaggedObject{..} ->
825− withObject "Object" $ \obj -> do
1123+ withObject tname $ \obj -> do
826− tag <- obj .: pack tagFieldName
1124+ tag <- contextType tname . contextTag tagKey cnames_ $ obj .: tagKey
827− fromMaybe (notFound tag) $
1125+ fromMaybe (badTag tag <?> Key tagKey) $
828− parseFromTaggedObject opts fargs contentsFieldName obj tag
1126+ parseFromTaggedObject (tag :* contentsFieldName :* p) obj
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])
830 ObjectWithSingleField ->
1134 ObjectWithSingleField ->
831− withObject "Object" $ \obj ->
832− case H.toList obj of
1135+ withObject tname $ \obj -> case H.toList obj of
833− [pair@(tag, _)] -> fromMaybe (notFound tag) $
1136+ [(tag, v)] -> maybe (badTag tag) (<?> Key tag) $
834− parsePair opts fargs pair
1137+ parsePair (tag :* p) v
835− _ -> fail "Object doesn't have a single field"
1138+ _ -> contextType tname . fail $
1139+ "expected an Object with a single pair, but found " ++
1140+ show (H.size obj) ++ " pairs"
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
837 TwoElemArray ->
1146 TwoElemArray ->
838− withArray "Array" $ \arr ->
1147+ withArray tname $ \arr -> case V.length arr of
839− if V.length arr == 2
1148+ 2 | String tag <- V.unsafeIndex arr 0 ->
840− then case V.unsafeIndex arr 0 of
1149+ maybe (badTag tag <?> Index 0) (<?> Index 1) $
841− String tag -> fromMaybe (notFound tag) $
842− parsePair opts fargs (tag, V.unsafeIndex arr 1)
1150+ parsePair (tag :* p) (V.unsafeIndex arr 1)
1152+ contextType tname $
843− _ -> fail "First element is not a String"
1153+ fail "tag element is not a String" <?> Index 0
844− else fail "Array doesn't have 2 elements"
1154+ len -> contextType tname . fail $
1155+ "expected a 2-element Array, but encountered an Array of length " ++
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
846− UntaggedValue -> parseUntaggedValue opts fargs
1162+ UntaggedValue -> parseUntaggedValue p
1164+ failWith_ = failWithCTags tname (constructorTagModifier opts)
848--------------------------------------------------------------------------------
1166--------------------------------------------------------------------------------
850class FromTaggedObject arity f where
1168class 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.
851− parseFromTaggedObject :: Options -> FromArgs arity a
1171+ parseFromTaggedObject
1172+ :: Text :* String :* TypeName :* Options :* FromArgs arity a
852− -> String -> Object
1173+ -> Object
853− -> Text -> Maybe (Parser (f a))
1174+ -> Maybe (Parser (f a))
855instance ( FromTaggedObject arity a, FromTaggedObject arity b) =>
1176instance ( FromTaggedObject arity a, FromTaggedObject arity b) =>
856 FromTaggedObject arity (a :+: b) where
1177 FromTaggedObject arity (a :+: b) where
857− parseFromTaggedObject opts fargs contentsFieldName obj tag =
1178+ parseFromTaggedObject p obj =
858− (fmap L1 <$> parseFromTaggedObject opts fargs contentsFieldName obj tag) <|>
1179+ (fmap L1 <$> parseFromTaggedObject p obj) <|>
859− (fmap R1 <$> parseFromTaggedObject opts fargs contentsFieldName obj tag)
1180+ (fmap R1 <$> parseFromTaggedObject p obj)
1182+instance ( IsRecord f isRecord
861−instance ( FromTaggedObject' arity f
1183+ , FromTaggedObject' arity f isRecord
862 , Constructor c
1184 , Constructor c
863 ) => FromTaggedObject arity (C1 c f) where
1185 ) => FromTaggedObject arity (C1 c f) where
864− parseFromTaggedObject opts fargs contentsFieldName obj tag
1186+ parseFromTaggedObject (tag :* contentsFieldName :* p@(_ :* opts :* _))
1189+ (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
865− | tag == name = Just $ M1 <$> parseFromTaggedObject'
1190+ parseFromTaggedObject' (contentsFieldName :* cname :* p)
866− opts fargs contentsFieldName obj
867− | otherwise = Nothing
1191+ | otherwise = const Nothing
869− name = pack $ constructorTagModifier opts $
1193+ tag' = pack $ constructorTagModifier opts cname
870− conName (undefined :: t c f p)
1194+ cname = conName (undefined :: M1 _i c _f _p)
872--------------------------------------------------------------------------------
1196--------------------------------------------------------------------------------
874−class FromTaggedObject' arity f where
1198+class FromTaggedObject' arity f isRecord where
875− parseFromTaggedObject' :: Options -> FromArgs arity a -> String
1199+ -- The first component of the parameter tuple is the contents field name.
876− -> Object -> Parser (f a)
1200+ parseFromTaggedObject'
878−class FromTaggedObject'' arity f isRecord where
879− parseFromTaggedObject'' :: Options -> FromArgs arity a -> String
1201+ :: String :* ConName :* TypeName :* Options :* FromArgs arity a
880− -> Object -> Tagged isRecord (Parser (f a))
1202+ -> Object -> Tagged isRecord (Parser (f a))
882−instance ( IsRecord f isRecord
883− , FromTaggedObject'' arity f isRecord
884− ) => FromTaggedObject' arity f where
1204+instance (RecordFromJSON arity f, FieldNames f) => FromTaggedObject' arity f True where
885− parseFromTaggedObject' opts fargs contentsFieldName =
1205+ -- Records are unpacked in the tagged object
886− (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
887− parseFromTaggedObject'' opts fargs contentsFieldName
1206+ parseFromTaggedObject' (_ :* p) = Tagged . recordParseJSON (True :* p)
889−instance (FromRecord arity f) => FromTaggedObject'' arity f True where
890− parseFromTaggedObject'' opts fargs _ =
891− Tagged . parseRecord opts fargs Nothing
893−instance (GFromJSON arity f) => FromTaggedObject'' arity f False where
1208+instance (ConsFromJSON arity f) => FromTaggedObject' arity f False where
1209+ -- Nonnullary nonrecords are encoded in the contents field
894− parseFromTaggedObject'' opts fargs contentsFieldName = Tagged .
1210+ parseFromTaggedObject' p obj = Tagged $ do
1211+ contents <- contextCons cname tname (obj .: key)
1212+ consParseJSON p' contents <?> Key key
895− (gParseJSON opts fargs <=< (.: pack contentsFieldName))
1214+ key = pack contentsFieldName
1215+ contentsFieldName :* p'@(cname :* tname :* _) = p
897−instance OVERLAPPING_ FromTaggedObject'' arity U1 False where
1217+instance OVERLAPPING_ FromTaggedObject' arity U1 False where
1218+ -- Nullary constructors don't need a contents field
898− parseFromTaggedObject'' _ _ _ _ = Tagged (pure U1)
1219+ parseFromTaggedObject' _ _ = Tagged (pure U1)
900--------------------------------------------------------------------------------
1221--------------------------------------------------------------------------------
1223+-- | Constructors need to be decoded differently depending on whether they're
1224+-- a record or not. This distinction is made by 'ConsParseJSON'.
902class ConsFromJSON arity f where
1225class ConsFromJSON arity f where
903− consParseJSON :: Options -> FromArgs arity a
1227+ :: ConName :* TypeName :* Options :* FromArgs arity a
904− -> Value -> Parser (f a)
1228+ -> Value -> Parser (f a)
906class ConsFromJSON' arity f isRecord where
1230class ConsFromJSON' arity f isRecord where
907− consParseJSON' :: Options -> FromArgs arity a
1232+ :: ConName :* TypeName :* Options :* FromArgs arity a
908− -> Maybe Text -- ^ A dummy label
909− -- (Nothing to use proper label)
910− -> Value -> Tagged isRecord (Parser (f a))
1233+ -> Value -> Tagged isRecord (Parser (f a))
912instance ( IsRecord f isRecord
1235instance ( IsRecord f isRecord
913 , ConsFromJSON' arity f isRecord
1236 , ConsFromJSON' arity f isRecord
914 ) => ConsFromJSON arity f where
1237 ) => ConsFromJSON arity f where
915− consParseJSON opts fargs v = let
1238+ consParseJSON p =
916− (v2,lab) = case (unwrapUnaryRecords opts,isUnary (undefined :: f a)) of
917− -- use a dummy object with a dummy label
918− (True,True) -> (object [(pack "dummy",v)], Just $ pack "dummy")
920− in (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a))
1239+ (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a))
921− $ consParseJSON' opts fargs lab v2
1240+ . consParseJSON' p
1242+instance OVERLAPPING_
1243+ ( GFromJSON arity a, RecordFromJSON arity (S1 s a)
1244+ ) => 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))
924−instance (FromRecord arity f) => ConsFromJSON' arity f True where
1249+instance RecordFromJSON arity f => ConsFromJSON' arity f True where
925− consParseJSON' opts fargs mlab = Tagged . withObject "record (:*:)"
1250+ consParseJSON' p@(cname :* tname :* _) =
926− (parseRecord opts fargs mlab)
1251+ Tagged . withObject (showCons cname tname) (recordParseJSON (False :* p))
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
1263+ "expected an empty Array, but encountered an Array of length " ++
1266+instance OVERLAPPING_
928−instance (GFromJSON arity f) => ConsFromJSON' arity f False where
1267+ GFromJSON arity f => ConsFromJSON' arity (S1 s f) False where
1268+ consParseJSON' (_ :* _ :* opts :* fargs) =
929− consParseJSON' opts fargs _ = Tagged . gParseJSON opts fargs
1269+ Tagged . fmap M1 . gParseJSON opts fargs
1271+instance (ProductFromJSON arity f, ProductSize f
1272+ ) => ConsFromJSON' arity f False where
1273+ consParseJSON' p = Tagged . productParseJSON0 p
931--------------------------------------------------------------------------------
1275--------------------------------------------------------------------------------
933−class FromRecord arity f where
1277+class FieldNames f where
934− parseRecord :: Options -> FromArgs arity a
1278+ fieldNames :: f a -> [Text] -> [Text]
935− -> Maybe Text -- ^ A dummy label
936− -- (Nothing to use proper label)
937− -> Object -> Parser (f a)
939−instance ( FromRecord arity a
1280+instance (FieldNames a, FieldNames b) => FieldNames (a :*: b) where
940− , FromRecord arity b
1281+ fieldNames _ =
941− ) => FromRecord arity (a :*: b) where
1282+ fieldNames (undefined :: a x) .
942− parseRecord opts fargs _ obj =
1283+ fieldNames (undefined :: b y)
943− (:*:) <$> parseRecord opts fargs Nothing obj
944− <*> parseRecord opts fargs Nothing obj
946−instance OVERLAPPABLE_ (Selector s, GFromJSON arity a) =>
1285+instance (Selector s) => FieldNames (S1 s f) where
947− FromRecord arity (S1 s a) where
1286+ fieldNames _ = (pack (selName (undefined :: M1 _i s _f _p)) :)
948− parseRecord opts fargs lab =
1287+
949− (<?> Key label) . gParseJSON opts fargs <=< (.: label)
1288+class RecordFromJSON arity f where
1290+ :: Bool :* ConName :* TypeName :* Options :* FromArgs arity a
1291+ -> Object -> Parser (f a)
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
951− label = fromMaybe defLabel lab
1299+ knownFields :: H.HashMap Text ()
1300+ knownFields = H.fromList $ map (,()) $
1301+ fieldNames (undefined :: f a)
1302+ [pack (tagFieldName (sumEncoding opts)) | fromTaggedSum]
1304+ if not (rejectUnknownFields opts)
1305+ then \_ -> return ()
1306+ else \obj -> case H.keys (H.difference obj knownFields) of
1308+ unknownFields -> contextCons cname tname $
1309+ fail ("unknown fields: " ++ show unknownFields)
1311+class RecordFromJSON' arity f where
1313+ :: ConName :* TypeName :* Options :* FromArgs arity a
1314+ -> Object -> Parser (f a)
1316+instance ( RecordFromJSON' arity a
1317+ , RecordFromJSON' arity b
1318+ ) => RecordFromJSON' arity (a :*: b) where
1319+ recordParseJSON' p obj =
1320+ (:*:) <$> recordParseJSON' p obj
1321+ <*> recordParseJSON' p obj
1323+instance OVERLAPPABLE_ (Selector s, GFromJSON arity a) =>
1324+ RecordFromJSON' arity (S1 s a) where
1325+ recordParseJSON' (cname :* tname :* opts :* fargs) obj = do
1326+ fv <- contextCons cname tname (obj .: label)
1327+ M1 <$> gParseJSON opts fargs fv <?> Key label
952− defLabel = pack . fieldLabelModifier opts $
1329+ label = pack $ fieldLabelModifier opts sname
953− selName (undefined :: t s a p)
1330+ sname = selName (undefined :: M1 _i s _f _p)
955instance INCOHERENT_ (Selector s, FromJSON a) =>
1332instance INCOHERENT_ (Selector s, FromJSON a) =>
956− FromRecord arity (S1 s (K1 i (Maybe a))) where
1333+ RecordFromJSON' arity (S1 s (K1 i (Maybe a))) where
957− parseRecord _ _ (Just lab) obj = (M1 . K1) <$> obj .:? lab
1334+ recordParseJSON' (_ :* _ :* opts :* _) obj = M1 . K1 <$> obj .:? pack label
958− parseRecord opts _ Nothing obj = (M1 . K1) <$> obj .:? pack label
960− label = fieldLabelModifier opts $
1336+ label = fieldLabelModifier opts sname
961− selName (undefined :: t s (K1 i (Maybe a)) p)
1337+ sname = selName (undefined :: M1 _i s _f _p)
1339+-- Parse an Option like a Maybe.
1340+instance INCOHERENT_ (Selector s, FromJSON a) =>
1341+ RecordFromJSON' arity (S1 s (K1 i (Semigroup.Option a))) where
1342+ recordParseJSON' p obj = wrap <$> recordParseJSON' p obj
1344+ wrap :: S1 s (K1 i (Maybe a)) p -> S1 s (K1 i (Semigroup.Option a)) p
1345+ wrap (M1 (K1 a)) = M1 (K1 (Semigroup.Option a))
963--------------------------------------------------------------------------------
1347--------------------------------------------------------------------------------
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)
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
965−class FromProduct arity f where
1369+class ProductFromJSON arity f where
966− parseProduct :: Options -> FromArgs arity a
1370+ productParseJSON :: ConName :* TypeName :* Options :* FromArgs arity a
967 -> Array -> Int -> Int
1371 -> Array -> Int -> Int
968 -> Parser (f a)
1372 -> Parser (f a)
970−instance ( FromProduct arity a
1374+instance ( ProductFromJSON arity a
971− , FromProduct arity b
1375+ , ProductFromJSON arity b
972− ) => FromProduct arity (a :*: b) where
1376+ ) => ProductFromJSON arity (a :*: b) where
973− parseProduct opts fargs arr ix len =
1377+ productParseJSON p arr ix len =
974− (:*:) <$> parseProduct opts fargs arr ix lenL
1378+ (:*:) <$> productParseJSON p arr ix lenL
975− <*> parseProduct opts fargs arr ixR lenR
1379+ <*> productParseJSON p arr ixR lenR
977 lenL = len `unsafeShiftR` 1
1381 lenL = len `unsafeShiftR` 1
978 ixR = ix + lenL
1382 ixR = ix + lenL
979 lenR = len - lenL
1383 lenR = len - lenL
981−instance (GFromJSON arity a) => FromProduct arity (S1 s a) where
1385+instance (GFromJSON arity a) => ProductFromJSON arity (S1 s a) where
982− parseProduct opts fargs arr ix _ =
1386+ productParseJSON (_ :* _ :* opts :* fargs) arr ix _ =
983− gParseJSON opts fargs $ V.unsafeIndex arr ix
1387+ M1 <$> gParseJSON opts fargs (V.unsafeIndex arr ix) <?> Index ix
985--------------------------------------------------------------------------------
1389--------------------------------------------------------------------------------
987class FromPair arity f where
1391class FromPair arity f where
1392+ -- The first component of the parameter tuple is the tag to match.
988− parsePair :: Options -> FromArgs arity a
1393+ parsePair :: Text :* TypeName :* Options :* FromArgs arity a
989− -> Pair -> Maybe (Parser (f a))
1395+ -> Maybe (Parser (f a))
991instance ( FromPair arity a
1397instance ( FromPair arity a
992 , FromPair arity b
1398 , FromPair arity b
993 ) => FromPair arity (a :+: b) where
1399 ) => FromPair arity (a :+: b) where
994− parsePair opts fargs pair = (fmap L1 <$> parsePair opts fargs pair) <|>
1401+ (fmap L1 <$> parsePair p pair) <|>
995− (fmap R1 <$> parsePair opts fargs pair)
1402+ (fmap R1 <$> parsePair p pair)
997instance ( Constructor c
1404instance ( Constructor c
999 , ConsFromJSON arity a
1405 , ConsFromJSON arity a
1000 ) => FromPair arity (C1 c a) where
1406 ) => FromPair arity (C1 c a) where
1001− parsePair opts fargs (tag, value)
1407+ parsePair (tag :* p@(_ :* opts :* _)) v
1002− | tag == tag' = Just $ gParseJSON opts fargs value
1408+ | tag == tag' = Just $ M1 <$> consParseJSON (cname :* p) v
1003 | otherwise = Nothing
1409 | otherwise = Nothing
1005− tag' = pack $ constructorTagModifier opts $
1411+ tag' = pack $ constructorTagModifier opts cname
1006− conName (undefined :: t c a p)
1412+ cname = conName (undefined :: M1 _i c _a _p)
1008--------------------------------------------------------------------------------
1414--------------------------------------------------------------------------------
1010class FromUntaggedValue arity f where
1416class FromUntaggedValue arity f where
1011− parseUntaggedValue :: Options -> FromArgs arity a
1417+ parseUntaggedValue :: TypeName :* Options :* FromArgs arity a
1012− -> Value -> Parser (f a)
1419+ -> Parser (f a)
1015 ( FromUntaggedValue arity a
1422 ( FromUntaggedValue arity a
1016 , FromUntaggedValue arity b
1423 , FromUntaggedValue arity b
1017 ) => FromUntaggedValue arity (a :+: b)
1424 ) => FromUntaggedValue arity (a :+: b)
1019− parseUntaggedValue opts fargs value =
1426+ parseUntaggedValue p value =
1020− L1 <$> parseUntaggedValue opts fargs value <|>
1427+ L1 <$> parseUntaggedValue p value <|>
1021− R1 <$> parseUntaggedValue opts fargs value
1428+ R1 <$> parseUntaggedValue p value
1023instance OVERLAPPABLE_
1430instance OVERLAPPABLE_
1024− ( GFromJSON arity a
1431+ ( ConsFromJSON arity a
1025− , ConsFromJSON arity a
1432+ , Constructor c
1026 ) => FromUntaggedValue arity (C1 c a)
1433 ) => FromUntaggedValue arity (C1 c a)
1028− parseUntaggedValue = gParseJSON
1435+ parseUntaggedValue p = fmap M1 . consParseJSON (cname :* p)
1437+ cname = conName (undefined :: M1 _i c _f _p)
1030instance OVERLAPPING_
1439instance OVERLAPPING_
1031 ( Constructor c )
1440 ( Constructor c )
1032 => FromUntaggedValue arity (C1 c U1)
1441 => FromUntaggedValue arity (C1 c U1)
1034− parseUntaggedValue opts _ (String s)
1443+ parseUntaggedValue (tname :* opts :* _) v =
1035− | s == pack (constructorTagModifier opts (conName (undefined :: t c U1 p))) =
1444+ contextCons cname tname $ case v of
1036− pure $ M1 U1
1446+ | tag == tag' -> pure $ M1 U1
1037− | otherwise =
1447+ | otherwise -> fail_ tag
1038− fail $ "Invalid tag: " ++ unpack s
1448+ _ -> typeMismatch "String" v
1039− parseUntaggedValue _ _ v = typeMismatch (conName (undefined :: t c U1 p)) v
1449+ where
1040−
1450+ tag' = pack $ constructorTagModifier opts cname
1041−
1451+ cname = conName (undefined :: M1 _i c _f _p)
1042−--------------------------------------------------------------------------------
1452+ fail_ tag = fail $
1043−
1453+ "expected tag " ++ show tag' ++ ", but found tag " ++ show tag
1044−notFound :: Text -> Parser a
1045−notFound key = fail $ "The key \"" ++ unpack key ++ "\" was not found"
1046−{-# INLINE notFound #-}
1048-------------------------------------------------------------------------------
1455-------------------------------------------------------------------------------
1049-- Instances
1456-- Instances
@@ -1101,17 +1508,20 @@ instance (FromJSON a, FromJSON b) => FromJSON (Either a b) where
1101 parseJSON = parseJSON2
1508 parseJSON = parseJSON2
1102 {-# INLINE parseJSON #-}
1509 {-# INLINE parseJSON #-}
1104−
1511+instance FromJSON Void where
1512+ parseJSON _ = fail "Cannot parse Void"
1513+ {-# INLINE parseJSON #-}
1106instance FromJSON Bool where
1515instance FromJSON Bool where
1107− parseJSON = withBool "Bool" pure
1516+ parseJSON (Bool b) = pure b
1517+ parseJSON v = typeMismatch "Bool" v
1108 {-# INLINE parseJSON #-}
1518 {-# INLINE parseJSON #-}
1110instance FromJSONKey Bool where
1520instance FromJSONKey Bool where
1111 fromJSONKey = FromJSONKeyTextParser $ \t -> case t of
1521 fromJSONKey = FromJSONKeyTextParser $ \t -> case t of
1112 "true" -> pure True
1522 "true" -> pure True
1113 "false" -> pure False
1523 "false" -> pure False
1114− _ -> fail $ "Cannot parse key into Bool: " ++ T.unpack t
1524+ _ -> fail $ "cannot parse key " ++ show t ++ " into Bool"
1116instance FromJSON Ordering where
1526instance FromJSON Ordering where
1117 parseJSON = withText "Ordering" $ \s ->
1527 parseJSON = withText "Ordering" $ \s ->
@@ -1119,25 +1529,30 @@ instance FromJSON Ordering where
1119 "LT" -> return LT
1529 "LT" -> return LT
1120 "EQ" -> return EQ
1530 "EQ" -> return EQ
1121 "GT" -> return GT
1531 "GT" -> return GT
1532+ _ -> fail $ "parsing Ordering failed, unexpected " ++ show s ++
1122− _ -> fail "Parsing Ordering value failed: expected \"LT\", \"EQ\", or \"GT\""
1533+ " (expected \"LT\", \"EQ\", or \"GT\")"
1124instance FromJSON () where
1535instance FromJSON () where
1125 parseJSON = withArray "()" $ \v ->
1536 parseJSON = withArray "()" $ \v ->
1126 if V.null v
1537 if V.null v
1127 then pure ()
1538 then pure ()
1128− else fail "Expected an empty array"
1539+ else prependContext "()" $ fail "expected an empty array"
1129 {-# INLINE parseJSON #-}
1540 {-# INLINE parseJSON #-}
1131instance FromJSON Char where
1542instance FromJSON Char where
1132− parseJSON = withText "Char" $ \t ->
1543+ parseJSON = withText "Char" parseChar
1133− if T.compareLength t 1 == EQ
1134− then pure $ T.head t
1135− else fail "Expected a string of length 1"
1136 {-# INLINE parseJSON #-}
1544 {-# INLINE parseJSON #-}
1138− parseJSONList = withText "String" $ pure . T.unpack
1546+ parseJSONList (String s) = pure (T.unpack s)
1547+ parseJSONList v = typeMismatch "String" v
1139 {-# INLINE parseJSONList #-}
1548 {-# INLINE parseJSONList #-}
1550+parseChar :: Text -> Parser Char
1552+ if T.compareLength t 1 == EQ
1553+ then pure $ T.head t
1554+ else prependContext "Char" $ fail "expected a string of length 1"
1141instance FromJSON Double where
1556instance FromJSON Double where
1142 parseJSON = parseRealFloat "Double"
1557 parseJSON = parseRealFloat "Double"
1143 {-# INLINE parseJSON #-}
1558 {-# INLINE parseJSON #-}
@@ -1149,12 +1564,6 @@ instance FromJSONKey Double where
1149 "-Infinity" -> pure (negate 1/0)
1564 "-Infinity" -> pure (negate 1/0)
1150 _ -> Scientific.toRealFloat <$> parseScientificText t
1565 _ -> Scientific.toRealFloat <$> parseScientificText t
1152−instance FromJSON Number where
1153− parseJSON (Number s) = pure $ scientificToNumber s
1154− parseJSON Null = pure (D (0/0))
1155− parseJSON v = typeMismatch "Number" v
1156− {-# INLINE parseJSON #-}
1158instance FromJSON Float where
1567instance FromJSON Float where
1159 parseJSON = parseRealFloat "Float"
1568 parseJSON = parseRealFloat "Float"
1160 {-# INLINE parseJSON #-}
1569 {-# INLINE parseJSON #-}
@@ -1167,17 +1576,30 @@ instance FromJSONKey Float where
1167 _ -> Scientific.toRealFloat <$> parseScientificText t
1576 _ -> Scientific.toRealFloat <$> parseScientificText t
1169instance (FromJSON a, Integral a) => FromJSON (Ratio a) where
1578instance (FromJSON a, Integral a) => FromJSON (Ratio a) where
1579+ parseJSON (Number x)
1581+ , exp10 >= -1024 = return $! realToFrac x
1582+ | otherwise = prependContext "Ratio" $ fail msg
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
1170− parseJSON = withObject "Rational" $ \obj ->
1589+ objParser = withObject "Rational" $ \obj -> do
1171− (%) <$> obj .: "numerator"
1590+ numerator <- obj .: "numerator"
1591+ denominator <- obj .: "denominator"
1592+ if denominator == 0
1593+ then fail "Ratio denominator was 0"
1172− <*> obj .: "denominator"
1594+ else pure $ numerator % denominator
1173− {-# INLINE parseJSON #-}
1595+ {-# INLINE parseJSON #-}
1175−-- | /WARNING:/ Only parse fixed-precision numbers from trusted input
1597+-- | This instance includes a bounds check to prevent maliciously
1176−-- since an attacker could easily fill up the memory of the target
1598+-- large inputs to fill up the memory of the target system. You can
1177−-- system by specifying a scientific number with a big exponent like
1599+-- newtype 'Scientific' and provide your own instance using
1178−-- @1e1000000000@.
1600+-- 'withScientific' if you want to allow larger inputs.
1179instance HasResolution a => FromJSON (Fixed a) where
1601instance HasResolution a => FromJSON (Fixed a) where
1180− parseJSON = withScientific "Fixed" $ pure . realToFrac
1602+ parseJSON = prependContext "Fixed" . withBoundedScientific' (pure . realToFrac)
1181 {-# INLINE parseJSON #-}
1603 {-# INLINE parseJSON #-}
1183instance FromJSON Int where
1605instance FromJSON Int where
@@ -1187,10 +1609,10 @@ instance FromJSON Int where
1187instance FromJSONKey Int where
1609instance FromJSONKey Int where
1188 fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int"
1610 fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int"
1190−-- | /WARNING:/ Only parse Integers from trusted input since an
1612+-- | This instance includes a bounds check to prevent maliciously
1191−-- attacker could easily fill up the memory of the target system by
1613+-- large inputs to fill up the memory of the target system. You can
1192−-- specifying a scientific number with a big exponent like
1614+-- newtype 'Scientific' and provide your own instance using
1193−-- @1e1000000000@.
1615+-- 'withScientific' if you want to allow larger inputs.
1194instance FromJSON Integer where
1616instance FromJSON Integer where
1195 parseJSON = parseIntegral "Integer"
1617 parseJSON = parseIntegral "Integer"
1196 {-# INLINE parseJSON #-}
1618 {-# INLINE parseJSON #-}
@@ -1199,16 +1621,21 @@ instance FromJSONKey Integer where
1199 fromJSONKey = FromJSONKeyTextParser $ parseIntegralText "Integer"
1621 fromJSONKey = FromJSONKeyTextParser $ parseIntegralText "Integer"
1201instance FromJSON Natural where
1623instance FromJSON Natural where
1202− parseJSON = withScientific "Natural" $ \s ->
1624+ parseJSON value = do
1203− if Scientific.coefficient s < 0
1625+ integer <- parseIntegral "Natural" value
1204− then fail $ "Expected a Natural number but got the negative number: " <> show s
1626+ parseNatural integer
1205− else pure $ truncate s
1207instance FromJSONKey Natural where
1628instance FromJSONKey Natural where
1208− fromJSONKey = FromJSONKeyTextParser $ \t -> parseScientificText t >>= \s ->
1629+ fromJSONKey = FromJSONKeyTextParser $ \text -> do
1209− if Scientific.coefficient s < 0
1630+ integer <- parseIntegralText "Natural" text
1631+ parseNatural integer
1633+parseNatural :: Integer -> Parser Natural
1634+parseNatural integer =
1635+ if integer < 0 then
1210− then fail $ "Expected a Natural number but got the negative number: " <> show s
1636+ fail $ "parsing Natural failed, unexpected negative number " <> show integer
1211− else pure $ truncate s
1637+ else
1638+ pure $ fromIntegral integer
1213instance FromJSON Int8 where
1640instance FromJSON Int8 where
1214 parseJSON = parseBoundedIntegral "Int8"
1641 parseJSON = parseBoundedIntegral "Int8"
@@ -1273,6 +1700,9 @@ instance FromJSON Word64 where
1273instance FromJSONKey Word64 where
1700instance FromJSONKey Word64 where
1274 fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word64"
1701 fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word64"
1703+instance FromJSON CTime where
1704+ parseJSON = fmap CTime . parseJSON
1705+ {-# INLINE parseJSON #-}
1277instance FromJSON Text where
1707instance FromJSON Text where
1278 parseJSON = withText "Text" pure
1708 parseJSON = withText "Text" pure
@@ -1302,17 +1732,17 @@ parseVersionText = go . readP_to_S parseVersion . unpack
1303 go [(v,[])] = return v
1733 go [(v,[])] = return v
1304 go (_ : xs) = go xs
1734 go (_ : xs) = go xs
1305− go _ = fail "could not parse Version"
1735+ go _ = fail "parsing Version failed"
1307-------------------------------------------------------------------------------
1737-------------------------------------------------------------------------------
1308-- semigroups NonEmpty
1738-- semigroups NonEmpty
1309-------------------------------------------------------------------------------
1739-------------------------------------------------------------------------------
1311instance FromJSON1 NonEmpty where
1741instance FromJSON1 NonEmpty where
1312− liftParseJSON p _ = withArray "NonEmpty a" $
1742+ liftParseJSON p _ = withArray "NonEmpty" $
1313 (>>= ne) . Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1743 (>>= ne) . Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1315− ne [] = fail "Expected a NonEmpty but got an empty list"
1745+ ne [] = fail "parsing NonEmpty failed, unexpected empty list"
1316 ne (x:xs) = pure (x :| xs)
1746 ne (x:xs) = pure (x :| xs)
1317 {-# INLINE liftParseJSON #-}
1747 {-# INLINE liftParseJSON #-}
@@ -1333,7 +1763,7 @@ instance FromJSON Scientific where
1333-------------------------------------------------------------------------------
1763-------------------------------------------------------------------------------
1335instance FromJSON1 DList.DList where
1765instance FromJSON1 DList.DList where
1336− liftParseJSON p _ = withArray "DList a" $
1766+ liftParseJSON p _ = withArray "DList" $
1337 fmap DList.fromList .
1767 fmap DList.fromList .
1338 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1768 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1339 {-# INLINE liftParseJSON #-}
1769 {-# INLINE liftParseJSON #-}
@@ -1360,7 +1790,7 @@ instance (FromJSON a) => FromJSON (Identity a) where
1360 parseJSONList = liftParseJSONList parseJSON parseJSONList
1790 parseJSONList = liftParseJSONList parseJSON parseJSONList
1361 {-# INLINE parseJSONList #-}
1791 {-# INLINE parseJSONList #-}
1363−instance (FromJSONKey a, FromJSON a) => FromJSONKey (Identity a) where
1793+instance (FromJSONKey a) => FromJSONKey (Identity a) where
1364 fromJSONKey = coerceFromJSONKeyFunction (fromJSONKey :: FromJSONKeyFunction a)
1794 fromJSONKey = coerceFromJSONKeyFunction (fromJSONKey :: FromJSONKeyFunction a)
1365 fromJSONKeyList = coerceFromJSONKeyFunction (fromJSONKeyList :: FromJSONKeyFunction [a])
1795 fromJSONKeyList = coerceFromJSONKeyFunction (fromJSONKeyList :: FromJSONKeyFunction [a])
@@ -1410,7 +1840,7 @@ instance (FromJSON1 f, FromJSON1 g) => FromJSON1 (Sum f g) where
1410 inr = "InR"
1840 inr = "InR"
1412 liftParseJSON _ _ _ = fail $
1842 liftParseJSON _ _ _ = fail $
1413− "expected an object with a single property " ++
1843+ "parsing Sum failed, expected an object with a single property " ++
1414 "where the property key should be either " ++
1844 "where the property key should be either " ++
1415 "\"InL\" or \"InR\""
1845 "\"InL\" or \"InR\""
1416 {-# INLINE liftParseJSON #-}
1846 {-# INLINE liftParseJSON #-}
@@ -1424,7 +1854,7 @@ instance (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Sum f g a) where
1424-------------------------------------------------------------------------------
1854-------------------------------------------------------------------------------
1426instance FromJSON1 Seq.Seq where
1856instance FromJSON1 Seq.Seq where
1427− liftParseJSON p _ = withArray "Seq a" $
1857+ liftParseJSON p _ = withArray "Seq" $
1428 fmap Seq.fromList .
1858 fmap Seq.fromList .
1429 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1859 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
1430 {-# INLINE liftParseJSON #-}
1860 {-# INLINE liftParseJSON #-}
@@ -1458,15 +1888,15 @@ instance FromJSON a => FromJSON (IntMap.IntMap a) where
1459instance (FromJSONKey k, Ord k) => FromJSON1 (M.Map k) where
1889instance (FromJSONKey k, Ord k) => FromJSON1 (M.Map k) where
1460 liftParseJSON p _ = case fromJSONKey of
1890 liftParseJSON p _ = case fromJSONKey of
1461− FromJSONKeyCoerce _-> withObject "Map k v" $
1891+ FromJSONKeyCoerce _ -> withObject "Map" $
1462 fmap (H.foldrWithKey (M.insert . unsafeCoerce) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1892 fmap (H.foldrWithKey (M.insert . unsafeCoerce) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1463− FromJSONKeyText f -> withObject "Map k v" $
1893+ FromJSONKeyText f -> withObject "Map" $
1464 fmap (H.foldrWithKey (M.insert . f) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1894 fmap (H.foldrWithKey (M.insert . f) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1465− FromJSONKeyTextParser f -> withObject "Map k v" $
1895+ FromJSONKeyTextParser f -> withObject "Map" $
1466 H.foldrWithKey (\k v m -> M.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure M.empty)
1896 H.foldrWithKey (\k v m -> M.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure M.empty)
1467− FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
1897+ FromJSONKeyValue f -> withArray "Map" $ \arr ->
1468− M.fromList <$> (Tr.sequence .
1898+ fmap M.fromList . Tr.sequence .
1469− zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr)
1899+ zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
1470 {-# INLINE liftParseJSON #-}
1900 {-# INLINE liftParseJSON #-}
1472instance (FromJSONKey k, Ord k, FromJSON v) => FromJSON (M.Map k v) where
1902instance (FromJSONKey k, Ord k, FromJSON v) => FromJSON (M.Map k v) where
@@ -1486,12 +1916,24 @@ instance (FromJSON v) => FromJSON (Tree.Tree v) where
1486 parseJSON = parseJSON1
1916 parseJSON = parseJSON1
1487 {-# INLINE parseJSON #-}
1917 {-# INLINE parseJSON #-}
1919+-------------------------------------------------------------------------------
1921+-------------------------------------------------------------------------------
1923+instance FromJSON UUID.UUID where
1924+ parseJSON = withText "UUID" $
1925+ maybe (fail "invalid UUID") pure . UUID.fromText
1927+instance FromJSONKey UUID.UUID where
1928+ fromJSONKey = FromJSONKeyTextParser $
1929+ maybe (fail "invalid UUID") pure . UUID.fromText
1489-------------------------------------------------------------------------------
1931-------------------------------------------------------------------------------
1490-- vector
1932-- vector
1491-------------------------------------------------------------------------------
1933-------------------------------------------------------------------------------
1493instance FromJSON1 Vector where
1935instance FromJSON1 Vector where
1494− liftParseJSON p _ = withArray "Vector a" $
1936+ liftParseJSON p _ = withArray "Vector" $
1495 V.mapM (uncurry $ parseIndexedJSON p) . V.indexed
1937 V.mapM (uncurry $ parseIndexedJSON p) . V.indexed
1496 {-# INLINE liftParseJSON #-}
1938 {-# INLINE liftParseJSON #-}
@@ -1505,14 +1947,14 @@ vectorParseJSON s = withArray s $ fmap V.convert . V.mapM (uncurry $ parseIndexe
1505{-# INLINE vectorParseJSON #-}
1947{-# INLINE vectorParseJSON #-}
1507instance (Storable a, FromJSON a) => FromJSON (VS.Vector a) where
1949instance (Storable a, FromJSON a) => FromJSON (VS.Vector a) where
1508− parseJSON = vectorParseJSON "Data.Vector.Storable.Vector a"
1950+ parseJSON = vectorParseJSON "Data.Vector.Storable.Vector"
1510instance (VP.Prim a, FromJSON a) => FromJSON (VP.Vector a) where
1952instance (VP.Prim a, FromJSON a) => FromJSON (VP.Vector a) where
1511− parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector a"
1953+ parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector"
1512 {-# INLINE parseJSON #-}
1954 {-# INLINE parseJSON #-}
1514instance (VG.Vector VU.Vector a, FromJSON a) => FromJSON (VU.Vector a) where
1956instance (VG.Vector VU.Vector a, FromJSON a) => FromJSON (VU.Vector a) where
1515− parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector a"
1957+ parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector"
1516 {-# INLINE parseJSON #-}
1958 {-# INLINE parseJSON #-}
1518-------------------------------------------------------------------------------
1960-------------------------------------------------------------------------------
@@ -1526,15 +1968,15 @@ instance (Eq a, Hashable a, FromJSON a) => FromJSON (HashSet.HashSet a) where
1527instance (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (H.HashMap k) where
1969instance (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (H.HashMap k) where
1528 liftParseJSON p _ = case fromJSONKey of
1970 liftParseJSON p _ = case fromJSONKey of
1529− FromJSONKeyCoerce _ -> withObject "HashMap ~Text v" $
1971+ FromJSONKeyCoerce _ -> withObject "HashMap ~Text" $
1530 uc . H.traverseWithKey (\k v -> p v <?> Key k)
1972 uc . H.traverseWithKey (\k v -> p v <?> Key k)
1531− FromJSONKeyText f -> withObject "HashMap k v" $
1973+ FromJSONKeyText f -> withObject "HashMap" $
1532 fmap (mapKey f) . H.traverseWithKey (\k v -> p v <?> Key k)
1974 fmap (mapKey f) . H.traverseWithKey (\k v -> p v <?> Key k)
1533− FromJSONKeyTextParser f -> withObject "HashMap k v" $
1975+ FromJSONKeyTextParser f -> withObject "HashMap" $
1534 H.foldrWithKey (\k v m -> H.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure H.empty)
1976 H.foldrWithKey (\k v m -> H.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure H.empty)
1535− FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
1977+ FromJSONKeyValue f -> withArray "Map" $ \arr ->
1536− H.fromList <$> (Tr.sequence .
1978+ fmap H.fromList . Tr.sequence .
1537− zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr)
1979+ zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
1539 uc :: Parser (H.HashMap Text v) -> Parser (H.HashMap k v)
1981 uc :: Parser (H.HashMap Text v) -> Parser (H.HashMap k v)
1540 uc = unsafeCoerce
1982 uc = unsafeCoerce
@@ -1555,11 +1997,33 @@ instance FromJSON DotNetTime where
1555 parseJSON = withText "DotNetTime" $ \t ->
1997 parseJSON = withText "DotNetTime" $ \t ->
1556 let (s,m) = T.splitAt (T.length t - 5) t
1998 let (s,m) = T.splitAt (T.length t - 5) t
1557 t' = T.concat [s,".",m]
1999 t' = T.concat [s,".",m]
1558− in case parseTime defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
2000+ in case parseTimeM True defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
1559 Just d -> pure (DotNetTime d)
2001 Just d -> pure (DotNetTime d)
1560 _ -> fail "could not parse .NET time"
2002 _ -> fail "could not parse .NET time"
1561 {-# INLINE parseJSON #-}
2003 {-# INLINE parseJSON #-}
2005+-------------------------------------------------------------------------------
2007+-------------------------------------------------------------------------------
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
2014+instance FromJSON a => FromJSON (PM.SmallArray a) where
2015+ parseJSON = fmap Exts.fromList . parseJSON
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
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
1563-------------------------------------------------------------------------------
2027-------------------------------------------------------------------------------
1565-------------------------------------------------------------------------------
2029-------------------------------------------------------------------------------
@@ -1585,6 +2049,17 @@ instance FromJSONKey LocalTime where
1585 fromJSONKey = FromJSONKeyTextParser (Time.run Time.localTime)
2049 fromJSONKey = FromJSONKeyTextParser (Time.run Time.localTime)
2052+-- | Supported string formats:
2054+-- @YYYY-MM-DD HH:MM Z@
2055+-- @YYYY-MM-DD HH:MM:SS Z@
2056+-- @YYYY-MM-DD HH:MM:SS.SSS Z@
2058+-- The first space may instead be a @T@, and the second space is
2059+-- optional. The @Z@ represents UTC. The @Z@ may be replaced with a
2060+-- time zone offset of the form @+0000@ or @-08:00@, where the first
2061+-- two digits are hours, the @:@ is optional and the second two digits
2062+-- (also optional) are minutes.
1588instance FromJSON ZonedTime where
2063instance FromJSON ZonedTime where
1589 parseJSON = withText "ZonedTime" (Time.run Time.zonedTime)
2064 parseJSON = withText "ZonedTime" (Time.run Time.zonedTime)
@@ -1599,14 +2074,57 @@ instance FromJSONKey UTCTime where
1599 fromJSONKey = FromJSONKeyTextParser (Time.run Time.utcTime)
2074 fromJSONKey = FromJSONKeyTextParser (Time.run Time.utcTime)
1602−-- | /WARNING:/ Only parse lengths of time from trusted input
2077+-- | This instance includes a bounds check to prevent maliciously
1603−-- since an attacker could easily fill up the memory of the target
2078+-- large inputs to fill up the memory of the target system. You can
1604−-- system by specifying a scientific number with a big exponent like
2079+-- newtype 'Scientific' and provide your own instance using
1605−-- @1e1000000000@.
2080+-- 'withScientific' if you want to allow larger inputs.
1606instance FromJSON NominalDiffTime where
2081instance FromJSON NominalDiffTime where
1607− parseJSON = withScientific "NominalDiffTime" $ pure . realToFrac
2082+ parseJSON = withBoundedScientific "NominalDiffTime" $ pure . realToFrac
1608 {-# INLINE parseJSON #-}
2083 {-# INLINE parseJSON #-}
2086+-- | This instance includes a bounds check to prevent maliciously
2087+-- large inputs to fill up the memory of the target system. You can
2088+-- newtype 'Scientific' and provide your own instance using
2089+-- 'withScientific' if you want to allow larger inputs.
2090+instance FromJSON DiffTime where
2091+ parseJSON = withBoundedScientific "DiffTime" $ pure . realToFrac
2092+ {-# INLINE parseJSON #-}
2094+instance FromJSON SystemTime where
2095+ parseJSON v = prependContext "SystemTime" $ do
2097+ let n' = floor (n * fromInteger (resolution n) :: Nano)
2098+ let (secs, nano) = n' `divMod` resolution n
2099+ return (MkSystemTime (fromInteger secs) (fromInteger nano))
2101+instance FromJSON CalendarDiffTime where
2102+ parseJSON = withObject "CalendarDiffTime" $ \obj -> CalendarDiffTime
2103+ <$> obj .: "months"
2106+instance FromJSON CalendarDiffDays where
2107+ parseJSON = withObject "CalendarDiffDays" $ \obj -> CalendarDiffDays
2108+ <$> obj .: "months"
2111+instance FromJSON DayOfWeek where
2112+ parseJSON = withText "DaysOfWeek" parseDayOfWeek
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"
2125+instance FromJSONKey DayOfWeek where
2126+ fromJSONKey = FromJSONKeyTextParser parseDayOfWeek
1610-------------------------------------------------------------------------------
2128-------------------------------------------------------------------------------
1611-- base Monoid/Semigroup
2129-- base Monoid/Semigroup
1612-------------------------------------------------------------------------------
2130-------------------------------------------------------------------------------
@@ -1725,11 +2243,21 @@ instance FromJSON a => FromJSON (Semigroup.Option a) where
1725-- tagged
2243-- tagged
1726-------------------------------------------------------------------------------
2244-------------------------------------------------------------------------------
2246+instance FromJSON1 Proxy where
2247+ {-# INLINE liftParseJSON #-}
2248+ liftParseJSON _ _ = fromNull "Proxy" Proxy
1728instance FromJSON (Proxy a) where
2250instance FromJSON (Proxy a) where
1729 {-# INLINE parseJSON #-}
2251 {-# INLINE parseJSON #-}
1730− parseJSON Null = pure Proxy
2252+ parseJSON = fromNull "Proxy" Proxy
1731− parseJSON v = typeMismatch "Proxy" v
2253+
2254+fromNull :: String -> a -> Value -> Parser a
2255+fromNull _ a Null = pure a
2256+fromNull c _ v = prependContext c (typeMismatch "Null" v)
2258+instance FromJSON2 Tagged where
2259+ liftParseJSON2 _ _ p _ = fmap Tagged . p
2260+ {-# INLINE liftParseJSON2 #-}
1734instance FromJSON1 (Tagged a) where
2262instance FromJSON1 (Tagged a) where
1735 liftParseJSON p _ = fmap Tagged . p
2263 liftParseJSON p _ = fmap Tagged . p
@@ -1752,10 +2280,7 @@ instance (FromJSON a, FromJSON b, FromJSON c) => FromJSONKey (a,b,c)
1752instance (FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSONKey (a,b,c,d)
2280instance (FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSONKey (a,b,c,d)
1754instance FromJSONKey Char where
2282instance FromJSONKey Char where
1755− fromJSONKey = FromJSONKeyTextParser $ \t ->
2283+ fromJSONKey = FromJSONKeyTextParser parseChar
1757− then return (T.index t 0)
1758− else typeMismatch "Expected Char but String didn't contain exactly one character" (String t)
1759 fromJSONKeyList = FromJSONKeyText T.unpack
2284 fromJSONKeyList = FromJSONKeyText T.unpack
1761instance (FromJSONKey a, FromJSON a) => FromJSONKey [a] where
2286instance (FromJSONKey a, FromJSON a) => FromJSONKey [a] where