@@ -1,28 +1,29 @@
1−{-# LANGUAGE CPP #-}
2−{-# LANGUAGE DataKinds #-}
3−{-# LANGUAGE DefaultSignatures #-}
4−{-# LANGUAGE FlexibleContexts #-}
5−{-# LANGUAGE FlexibleInstances #-}
6−{-# LANGUAGE GADTs #-}
1+{-# LANGUAGE CPP #-}
2+{-# LANGUAGE DataKinds #-}
3+{-# LANGUAGE DefaultSignatures #-}
4+{-# LANGUAGE FlexibleContexts #-}
5+{-# LANGUAGE FlexibleInstances #-}
6+{-# LANGUAGE GADTs #-}
77{-# LANGUAGE MultiParamTypeClasses #-}
8−{-# LANGUAGE NoImplicitPrelude #-}
9−{-# LANGUAGE OverloadedStrings #-}
10−{-# LANGUAGE PolyKinds #-}
11−{-# LANGUAGE RecordWildCards #-}
12−{-# LANGUAGE ScopedTypeVariables #-}
13−{-# LANGUAGE TypeOperators #-}
14−{-# LANGUAGE TupleSections #-}
15−{-# LANGUAGE UndecidableInstances #-}
16−{-# LANGUAGE ViewPatterns #-}
17−
18−#include "incoherent-compat.h"
8+{-# LANGUAGE NamedFieldPuns #-}
9+{-# LANGUAGE OverloadedStrings #-}
10+{-# LANGUAGE RecordWildCards #-}
11+{-# LANGUAGE ScopedTypeVariables #-}
12+{-# LANGUAGE TypeOperators #-}
13+{-# LANGUAGE TypeSynonymInstances #-}
14+{-# LANGUAGE UndecidableInstances #-}
15+{-# LANGUAGE ViewPatterns #-}
16+
17+#if __GLASGOW_HASKELL__ >= 706
18+{-# LANGUAGE PolyKinds #-}
19+#endif
20+
1921#include "overlapping-compat.h"
2022
2123-- TODO: Drop this when we remove support for Data.Attoparsec.Number
2224{-# OPTIONS_GHC -fno-warn-deprecations #-}
2325
24−module Data.Aeson.Types.FromJSON
25− (
26+module Data.Aeson.Types.FromJSON (
2627 -- * Core JSON classes
2728 FromJSON(..)
2829 -- * Liftings to unary and binary type constructors
@@ -32,7 +33,6 @@ module Data.Aeson.Types.FromJSON
3233 , parseJSON2
3334 -- * Generic JSON classes
3435 , GFromJSON(..)
35− , FromArgs(..)
3636 , genericParseJSON
3737 , genericLiftParseJSON
3838 -- * Classes and types for map keys
@@ -42,121 +42,104 @@ module Data.Aeson.Types.FromJSON
4242 , coerceFromJSONKeyFunction
4343 , mapFromJSONKeyFunction
4444
45− , GFromJSONKey()
46− , genericFromJSONKey
47−
4845 -- * List functions
4946 , listParser
5047
51− -- * Inspecting @'Value's@
48+ -- * Inspecting @'Value's@
5249 , withObject
5350 , withText
5451 , withArray
52+ , withNumber
5553 , withScientific
5654 , withBool
57− , withEmbeddedJSON
5855
5956 -- * Functions
6057 , fromJSON
6158 , ifromJSON
62− , typeMismatch
63− , unexpected
64− , parseField
65− , parseFieldMaybe
66− , parseFieldMaybe'
67− , explicitParseField
68− , explicitParseFieldMaybe
69− , explicitParseFieldMaybe'
70− , parseIndexedJSON
71− -- ** Operators
7259 , (.:)
7360 , (.:?)
7461 , (.:!)
7562 , (.!=)
63+ , typeMismatch
7664
7765 -- * Internal
7866 , parseOptionalFieldWith
7967 ) where
8068
81−import Prelude.Compat
69+import Prelude ()
70+import Prelude.Compat hiding (foldr)
8271
83−import Control.Applicative ((<|>), Const(..), liftA2)
84−import Control.Monad (zipWithM)
8572import Data.Aeson.Internal.Functions (mapKey)
86−import Data.Aeson.Parser.Internal (eitherDecodeWith, jsonEOF)
8773import Data.Aeson.Types.Generic
8874import Data.Aeson.Types.Internal
89−import Data.Bits (unsafeShiftR)
90−import Data.Fixed (Fixed, HasResolution (resolution), Nano)
91−import Data.Functor.Compose (Compose(..))
92−import Data.Functor.Identity (Identity(..))
93−import Data.Functor.Product (Product(..))
94−import Data.Functor.Sum (Sum(..))
95−import Data.Hashable (Hashable(..))
96−import Data.Int (Int16, Int32, Int64, Int8)
97−import Data.List.NonEmpty (NonEmpty(..))
98−import Data.Maybe (fromMaybe)
99−import Data.Semigroup ((<>))
100−import Data.Proxy (Proxy(..))
101−import Data.Ratio ((%), Ratio)
102−import Data.Scientific (Scientific, base10Exponent)
103−import Data.Tagged (Tagged(..))
104−import Data.Text (Text, pack, unpack)
105−import Data.Time (Day, DiffTime, LocalTime, NominalDiffTime, TimeOfDay, UTCTime, ZonedTime)
106−import Data.Time.Calendar.Compat (CalendarDiffDays (..), DayOfWeek (..))
107−import Data.Time.LocalTime.Compat (CalendarDiffTime (..))
108−import Data.Time.Clock.System.Compat (SystemTime (..))
109−import Data.Time.Format.Compat (parseTimeM, defaultTimeLocale)
110−import Data.Traversable as Tr (sequence)
111−import Data.Vector (Vector)
112−import Data.Version (Version, parseVersion)
113−import Data.Void (Void)
114−import Data.Word (Word16, Word32, Word64, Word8)
115−import Foreign.Storable (Storable)
116−import Foreign.C.Types (CTime (..))
75+
76+import qualified Data.Aeson.Parser.Time as Time
77+import qualified Data.Attoparsec.ByteString.Char8 as A (endOfInput, parseOnly,
78+ scientific)
79+
80+import Control.Applicative (Const (..), (<|>))
81+import Control.Monad ((<=<))
82+import Data.Attoparsec.Number (Number (..))
83+import Data.Bits (unsafeShiftR)
84+import Data.Fixed (Fixed, HasResolution)
85+import Data.Functor.Compose (Compose (..))
86+import Data.Functor.Identity (Identity (..))
87+import Data.Hashable (Hashable (..))
88+import Data.Int (Int16, Int32, Int64, Int8)
89+import Data.List.NonEmpty (NonEmpty (..))
90+import Data.Maybe (fromMaybe)
91+import Data.Monoid (Dual (..), First (..), Last (..), (<>))
92+import Data.Proxy (Proxy (..))
93+import Data.Ratio (Ratio, (%))
94+import Data.Scientific (Scientific)
95+import Data.Tagged (Tagged (..))
96+import Data.Text (Text, pack, unpack)
97+import Data.Time (Day, LocalTime, NominalDiffTime, TimeOfDay,
98+ UTCTime, ZonedTime)
99+import Data.Time.Format (parseTime)
100+import Data.Time.Locale.Compat (defaultTimeLocale)
101+import Data.Traversable as Tr (sequence)
102+import Data.Vector (Vector)
103+import Data.Version (Version, parseVersion)
104+import Data.Word (Word16, Word32, Word64, Word8)
105+import Foreign.Storable (Storable)
117106import GHC.Generics
118−import Numeric.Natural (Natural)
107+import Numeric.Natural (Natural)
119108import Text.ParserCombinators.ReadP (readP_to_S)
120−import Unsafe.Coerce (unsafeCoerce)
121−import qualified Data.Aeson.Parser.Time as Time
122−import qualified Data.Attoparsec.ByteString.Char8 as A (endOfInput, parseOnly, scientific)
123−import qualified Data.ByteString.Lazy as L
124−import qualified Data.DList as DList
125−import qualified Data.HashMap.Strict as H
126−import qualified Data.HashSet as HashSet
127−import qualified Data.IntMap as IntMap
128−import qualified Data.IntSet as IntSet
129−import qualified Data.Map as M
130−import qualified Data.Monoid as Monoid
131−import qualified Data.Scientific as Scientific
132−import qualified Data.Semigroup as Semigroup
133−import qualified Data.Sequence as Seq
134−import qualified Data.Set as Set
135−import qualified Data.Text as T
136−import qualified Data.Text.Encoding as T
137−import qualified Data.Text.Lazy as LT
138−import qualified Data.Tree as Tree
139−import qualified Data.UUID.Types as UUID
140−import qualified Data.Vector as V
141−import qualified Data.Vector.Generic as VG
109+
110+import qualified Data.DList as DList
111+import qualified Data.HashMap.Strict as H
112+import qualified Data.HashSet as HashSet
113+import qualified Data.IntMap as IntMap
114+import qualified Data.IntSet as IntSet
115+import qualified Data.Map as M
116+import qualified Data.Scientific as Scientific
117+import qualified Data.Sequence as Seq
118+import qualified Data.Set as Set
119+import qualified Data.Text as T
120+import qualified Data.Text.Encoding as T
121+import qualified Data.Text.Lazy as LT
122+import qualified Data.Tree as Tree
123+import qualified Data.Vector as V
124+import qualified Data.Vector.Generic as VG
142125import qualified Data.Vector.Primitive as VP
143−import qualified Data.Vector.Storable as VS
144−import qualified Data.Vector.Unboxed as VU
126+import qualified Data.Vector.Storable as VS
127+import qualified Data.Vector.Unboxed as VU
145128
146−import qualified GHC.Exts as Exts
147−import qualified Data.Primitive.Array as PM
148−import qualified Data.Primitive.SmallArray as PM
149−import qualified Data.Primitive.Types as PM
129+import Unsafe.Coerce (unsafeCoerce)
150130
151−#if MIN_VERSION_primitive(0,6,4)
152−#if !MIN_VERSION_primitive(0,7,0)
153−import qualified Data.Primitive.UnliftedArray as PM
131+#ifndef HAS_COERCIBLE
132+#define HAS_COERCIBLE (__GLASGOW_HASKELL__ >= 707)
154133#endif
155−import qualified Data.Primitive.PrimArray as PM
156−#endif
157−
158134
135+#if HAS_COERCIBLE
159136import Data.Coerce (Coercible, coerce)
137+coerce' :: Coercible a b => a -> b
138+coerce' = coerce
139+#else
140+coerce' :: a -> b
141+coerce' = unsafeCoerce
142+#endif
160143
161144parseIndexedJSON :: (Value -> Parser a) -> Int -> Value -> Parser a
162145parseIndexedJSON p idx value = p value <?> Index idx
@@ -165,7 +148,7 @@ parseIndexedJSON p idx value = p value <?> Index idx
165148parseIndexedJSONPair :: (Value -> Parser a) -> (Value -> Parser b) -> Int -> Value -> Parser (a, b)
166149parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
167150 where
168− p = withArray "(k, v)" $ \ab ->
151+ p = withArray "(k,v)" $ \ab ->
169152 let n = V.length ab
170153 in if n == 2
171154 then (,) <$> parseJSONElemAtIndex keyParser 0 ab
@@ -177,57 +160,33 @@ parseIndexedJSONPair keyParser valParser idx value = p value <?> Index idx
177160parseJSONElemAtIndex :: (Value -> Parser a) -> Int -> V.Vector Value -> Parser a
178161parseJSONElemAtIndex p idx ary = p (V.unsafeIndex ary idx) <?> Index idx
179162
163+scientificToNumber :: Scientific -> Number
164+scientificToNumber s
165+ | e < 0 = D $ Scientific.toRealFloat s
166+ | otherwise = I $ c * 10 ^ e
167+ where
168+ e = Scientific.base10Exponent s
169+ c = Scientific.coefficient s
170+{-# INLINE scientificToNumber #-}
171+
180172parseRealFloat :: RealFloat a => String -> Value -> Parser a
181−parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
182−parseRealFloat _ Null = pure (0/0)
183−parseRealFloat name v = prependContext name (unexpected v)
173+parseRealFloat _ (Number s) = pure $ Scientific.toRealFloat s
174+parseRealFloat _ Null = pure (0/0)
175+parseRealFloat expected v = typeMismatch expected v
184176{-# INLINE parseRealFloat #-}
185177
186−parseIntegralFromScientific :: forall a. Integral a => Scientific -> Parser a
187−parseIntegralFromScientific s =
188− case Scientific.floatingOrInteger s :: Either Double a of
189− Right x -> pure x
190− Left _ -> fail $ "unexpected floating number " ++ show s
191−{-# INLINE parseIntegralFromScientific #-}
192−
193178parseIntegral :: Integral a => String -> Value -> Parser a
194−parseIntegral name =
195− prependContext name . withBoundedScientific' parseIntegralFromScientific
179+parseIntegral expected = withScientific expected $ pure . truncate
196180{-# INLINE parseIntegral #-}
197181
198−parseBoundedIntegralFromScientific :: (Bounded a, Integral a) => Scientific -> Parser a
199−parseBoundedIntegralFromScientific s = maybe
200− (fail $ "value is either floating or will cause over or underflow " ++ show s)
201− pure
202− (Scientific.toBoundedInteger s)
203−{-# INLINE parseBoundedIntegralFromScientific #-}
204−
205−parseBoundedIntegral :: (Bounded a, Integral a) => String -> Value -> Parser a
206−parseBoundedIntegral name =
207− prependContext name . withScientific' parseBoundedIntegralFromScientific
208−{-# INLINE parseBoundedIntegral #-}
209−
210182parseScientificText :: Text -> Parser Scientific
211183parseScientificText
212184 = either fail pure
213185 . A.parseOnly (A.scientific <* A.endOfInput)
214186 . T.encodeUtf8
215187
216−parseIntegralText :: Integral a => String -> Text -> Parser a
217−parseIntegralText name t =
218− prependContext name $
219− parseScientificText t
220− >>= rejectLargeExponent
221− >>= parseIntegralFromScientific
222− where
223− rejectLargeExponent :: Scientific -> Parser Scientific
224− rejectLargeExponent s = withBoundedScientific' pure (Number s)
225−{-# INLINE parseIntegralText #-}
226−
227−parseBoundedIntegralText :: (Bounded a, Integral a) => String -> Text -> Parser a
228−parseBoundedIntegralText name t =
229− prependContext name $
230− parseScientificText t >>= parseBoundedIntegralFromScientific
188+parseIntegralText :: Integral a => Text -> Parser a
189+parseIntegralText t = truncate <$> parseScientificText t
231190
232191parseOptionalFieldWith :: (Value -> Parser (Maybe a))
233192 -> Object -> Text -> Parser (Maybe a)
@@ -246,21 +205,16 @@ class GFromJSON arity f where
246205 -- | This method (applied to 'defaultOptions') is used as the
247206 -- default generic implementation of 'parseJSON' (if the @arity@ is 'Zero')
248207 -- or 'liftParseJSON' (if the @arity@ is 'One').
249− gParseJSON :: Options -> FromArgs arity a -> Value -> Parser (f a)
250−
251−-- | A 'FromArgs' value either stores nothing (for 'FromJSON') or it stores the
252−-- two function arguments that decode occurrences of the type parameter (for
253−-- 'FromJSON1').
254−data FromArgs arity a where
255− NoFromArgs :: FromArgs Zero a
256− From1Args :: (Value -> Parser a) -> (Value -> Parser [a]) -> FromArgs One a
208+ gParseJSON :: Options -> Proxy arity
209+ -> (Value -> Parser a) -> (Value -> Parser [a])
210+ -> Value -> Parser (f a)
257211
258212-- | A configurable generic JSON decoder. This function applied to
259213-- 'defaultOptions' is used as the default for 'parseJSON' when the
260214-- type is an instance of 'Generic'.
261215genericParseJSON :: (Generic a, GFromJSON Zero (Rep a))
262216 => Options -> Value -> Parser a
263−genericParseJSON opts = fmap to . gParseJSON opts NoFromArgs
217+genericParseJSON opts = fmap to . gParseJSON opts proxyZero undefined undefined
264218
265219-- | A configurable generic JSON decoder. This function applied to
266220-- 'defaultOptions' is used as the default for 'liftParseJSON' when the
@@ -268,7 +222,7 @@ genericParseJSON opts = fmap to . gParseJSON opts NoFromArgs
268222genericLiftParseJSON :: (Generic1 f, GFromJSON One (Rep1 f))
269223 => Options -> (Value -> Parser a) -> (Value -> Parser [a])
270224 -> Value -> Parser (f a)
271−genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
225+genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts proxyOne pj pjl
272226
273227-------------------------------------------------------------------------------
274228-- Class
@@ -287,21 +241,14 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
287241--
288242-- The basic ways to signal a failed conversion are as follows:
289243--
290−-- * 'fail' yields a custom error message: it is the recommended way of
291−-- reporting a failure;
292−--
293−-- * 'Control.Applicative.empty' (or 'Control.Monad.mzero') is uninformative:
294−-- use it when the error is meant to be caught by some @('<|>')@;
244+-- * 'empty' and 'mzero' work, but are terse and uninformative
295245--
296−-- * 'typeMismatch' can be used to report a failure when the encountered value
297−-- is not of the expected JSON type; 'unexpected' is an appropriate alternative
298−-- when more than one type may be expected, or to keep the expected type
299−-- implicit.
246+-- * 'fail' yields a custom error message
300247--
301−-- 'prependFailure' (or 'modifyFailure') add more information to a parser's
302−-- error messages.
248+-- * 'typeMismatch' produces an informative message for cases when the
249+-- value encountered is not of the expected type
303250--
304−-- An example type and instance using 'typeMismatch' and 'prependFailure':
251+-- An example type and instance:
305252--
306253-- @
307254-- \-- Allow ourselves to write 'Text' literals.
@@ -309,30 +256,15 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
309256--
310257-- data Coord = Coord { x :: Double, y :: Double }
311258--
312−-- instance 'FromJSON' Coord where
313−-- 'parseJSON' ('Object' v) = Coord
314−-- '<$>' v '.:' \"x\"
315−-- '<*>' v '.:' \"y\"
259+-- instance FromJSON Coord where
260+-- parseJSON ('Object' v) = Coord '<$>'
261+-- v '.:' \"x\" '<*>'
262+-- v '.:' \"y\"
316263--
317−-- \-- We do not expect a non-'Object' value here.
318−-- \-- We could use 'Control.Applicative.empty' to fail, but 'typeMismatch'
319−-- \-- gives a much more informative error message.
320−-- 'parseJSON' invalid =
321−-- 'prependFailure' "parsing Coord failed, "
322−-- ('typeMismatch' \"Object\" invalid)
323−-- @
324−--
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:
330−--
331−-- @
332−-- instance 'FromJSON' Coord where
333−-- 'parseJSON' = 'withObject' \"Coord\" $ \\v -> Coord
334−-- '<$>' v '.:' \"x\"
335−-- '<*>' v '.:' \"y\"
264+-- \-- We do not expect a non-'Object' value here.
265+-- \-- We could use 'mzero' to fail, but 'typeMismatch'
266+-- \-- gives a much more informative error message.
267+-- parseJSON invalid = 'typeMismatch' \"Coord\" invalid
336268-- @
337269--
338270-- Instead of manually writing your 'FromJSON' instance, there are two options
@@ -340,7 +272,7 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
340272--
341273-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
342274-- instance at compile time. The generated instance is optimized for your type
343−-- so it will probably be more efficient than the following option.
275+-- so will probably be more efficient than the following two options:
344276--
345277-- * The compiler can provide a default generic implementation for
346278-- 'parseJSON'.
@@ -358,21 +290,18 @@ genericLiftParseJSON opts pj pjl = fmap to1 . gParseJSON opts (From1Args pj pjl)
358290--
359291-- data Coord = Coord { x :: Double, y :: Double } deriving 'Generic'
360292--
361−-- instance 'FromJSON' Coord
293+-- instance FromJSON Coord
362294-- @
363295--
364−-- The default implementation will be equivalent to
365−-- @parseJSON = 'genericParseJSON' 'defaultOptions'@; if you need different
366−-- options, you can customize the generic decoding by defining:
296+-- If @DefaultSignatures@ doesn't give exactly the results you want,
297+-- you can customize the generic decoding with only a tiny amount of
298+-- effort, using 'genericParseJSON' with your preferred 'Options':
367299--
368300-- @
369−-- customOptions = 'defaultOptions'
370−-- { 'fieldLabelModifier' = 'map' 'Data.Char.toUpper'
371−-- }
372−--
373−-- instance 'FromJSON' Coord where
374−-- 'parseJSON' = 'genericParseJSON' customOptions
301+-- instance FromJSON Coord where
302+-- parseJSON = 'genericParseJSON' 'defaultOptions'
375303-- @
304+
376305class FromJSON a where
377306 parseJSON :: Value -> Parser a
378307
@@ -380,89 +309,61 @@ class FromJSON a where
380309 parseJSON = genericParseJSON defaultOptions
381310
382311 parseJSONList :: Value -> Parser [a]
383− parseJSONList = withArray "[]" $ \a ->
384− zipWithM (parseIndexedJSON parseJSON) [0..]
312+ parseJSONList (Array a)
313+ = sequence
314+ . zipWith (parseIndexedJSON parseJSON) [0..]
385315 . V.toList
386316 $ a
387317
318+ parseJSONList v = typeMismatch "[a]" v
319+
388320-------------------------------------------------------------------------------
389321-- Classes and types for map keys
390322-------------------------------------------------------------------------------
391323
392−-- | Read the docs for 'ToJSONKey' first. This class is a conversion
393−-- in the opposite direction. If you have a newtype wrapper around 'Text',
394−-- the recommended way to define instances is with generalized newtype deriving:
395−--
396−-- > newtype SomeId = SomeId { getSomeId :: Text }
397−-- > deriving (Eq,Ord,Hashable,FromJSONKey)
398−--
399−-- If you have a sum of nullary constructors, you may use the generic
400−-- implementation:
401−--
402−-- @
403−-- data Color = Red | Green | Blue
404−-- deriving Generic
405−--
406−-- instance 'FromJSONKey' Color where
407−-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
408−-- @
409324class FromJSONKey a where
410− -- | Strategy for parsing the key of a map-like container.
411325 fromJSONKey :: FromJSONKeyFunction a
412326 default fromJSONKey :: FromJSON a => FromJSONKeyFunction a
413327 fromJSONKey = FromJSONKeyValue parseJSON
414328
415− -- | This is similar in spirit to the 'readList' method of 'Read'.
416− -- It makes it possible to give 'String' keys special treatment
417− -- without using @OverlappingInstances@. End users should always
418− -- be able to use the default implementation of this method.
419329 fromJSONKeyList :: FromJSONKeyFunction [a]
420330 default fromJSONKeyList :: FromJSON a => FromJSONKeyFunction [a]
421331 fromJSONKeyList = FromJSONKeyValue parseJSON
422332
423−-- | With GHC 7.8+ we carry around @'Coercible' 'Text' a@ dictionary,
424−-- to give us an assurance that the program will not segfault.
425−-- Unfortunately we cannot enforce that the 'Eq' instances or the
426−-- 'Hashable' instances for 'Text' and @a@ agree.
333+-- | With GHC 7.8 + we carry around 'Coercible Text a' dictionary,
334+-- to have even some amount of safety net.
335+-- Unfortunately we cannot enforce that 'Hashable' instance agree on the type level
427336--
428−-- At the moment this type is intentionally not exported. 'FromJSONKeyFunction'
429−-- can be inspected, but cannot be constructed.
337+-- ATM this type is intentionally not exported. FromJSONKeyFunction can be inspected,
338+-- but cannot be constructed.
430339data CoerceText a where
340+#if HAS_COERCIBLE
431341 CoerceText :: Coercible Text a => CoerceText a
342+#else
343+ CoerceText :: CoerceText a
344+#endif
432345
433−-- | This type is related to 'ToJSONKeyFunction'. If 'FromJSONKeyValue' is used in the
434−-- 'FromJSONKey' instance, then 'ToJSONKeyValue' should be used in the 'ToJSONKey'
435−-- instance. The other three data constructors for this type all correspond to
436−-- 'ToJSONKeyText'. Strictly speaking, 'FromJSONKeyTextParser' is more powerful than
437−-- 'FromJSONKeyText', which is in turn more powerful than 'FromJSONKeyCoerce'.
438−-- For performance reasons, these exist as three options instead of one.
439346data FromJSONKeyFunction a
440347 = FromJSONKeyCoerce !(CoerceText a)
441− -- ^ uses 'coerce' ('unsafeCoerce' in older GHCs)
442348 | FromJSONKeyText !(Text -> a)
443− -- ^ conversion from 'Text' that always succeeds
444349 | FromJSONKeyTextParser !(Text -> Parser a)
445− -- ^ conversion from 'Text' that may fail
446350 | FromJSONKeyValue !(Value -> Parser a)
447− -- ^ conversion for non-textual keys
448351
449−-- | Only law abiding up to interpretation
450352instance Functor FromJSONKeyFunction where
451− fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce)
353+ fmap h (FromJSONKeyCoerce CoerceText) = FromJSONKeyText (h . coerce')
452354 fmap h (FromJSONKeyText f) = FromJSONKeyText (h . f)
453355 fmap h (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap h . f)
454356 fmap h (FromJSONKeyValue f) = FromJSONKeyValue (fmap h . f)
455357
456358-- | Construct 'FromJSONKeyFunction' for types coercible from 'Text'. This
457359-- conversion is still unsafe, as 'Hashable' and 'Eq' instances of @a@ should be
458−-- compatible with 'Text' i.e. hash values should be equal for wrapped values as well.
459−-- This property will always be maintained if the 'Hashable' and 'Eq' instances
460−-- are derived with generalized newtype deriving.
461360-- compatible with 'Text' i.e. hash values be equal for wrapped values as well.
462361--
463362-- On pre GHC 7.8 this is unconstrainted function.
464363fromJSONKeyCoerce ::
364+#if HAS_COERCIBLE
465365 Coercible Text a =>
366+#endif
466367 FromJSONKeyFunction a
467368fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
468369
@@ -470,91 +371,60 @@ fromJSONKeyCoerce = FromJSONKeyCoerce CoerceText
470371--
471372-- See note on 'fromJSONKeyCoerce'.
472373coerceFromJSONKeyFunction ::
374+#if HAS_COERCIBLE
473375 Coercible a b =>
376+#endif
474377 FromJSONKeyFunction a -> FromJSONKeyFunction b
378+#if HAS_COERCIBLE
475379coerceFromJSONKeyFunction = coerce
380+#else
381+coerceFromJSONKeyFunction (FromJSONKeyCoerce CoerceText) = FromJSONKeyCoerce CoerceText
382+coerceFromJSONKeyFunction (FromJSONKeyText f) = FromJSONKeyText (coerce' . f)
383+coerceFromJSONKeyFunction (FromJSONKeyTextParser f) = FromJSONKeyTextParser (fmap coerce' . f)
384+coerceFromJSONKeyFunction (FromJSONKeyValue f) = FromJSONKeyValue (fmap coerce' . f)
385+#endif
476386
477387{-# RULES
478388 "FromJSONKeyCoerce: fmap id" forall (x :: FromJSONKeyFunction a).
479389 fmap id x = x
480390 #-}
391+#if HAS_COERCIBLE
481392{-# RULES
482393 "FromJSONKeyCoerce: fmap coerce" forall x .
483394 fmap coerce x = coerceFromJSONKeyFunction x
484395 #-}
396+#endif
485397
486398-- | Same as 'fmap'. Provided for the consistency with 'ToJSONKeyFunction'.
487399mapFromJSONKeyFunction :: (a -> b) -> FromJSONKeyFunction a -> FromJSONKeyFunction b
488400mapFromJSONKeyFunction = fmap
489401
490−-- | 'fromJSONKey' for 'Generic' types.
491−-- These types must be sums of nullary constructors, whose names will be used
492−-- as keys for JSON objects.
493−--
494−-- See also 'genericToJSONKey'.
495−--
496−-- === __Example__
497−--
498−-- @
499−-- data Color = Red | Green | Blue
500−-- deriving 'Generic'
501−--
502−-- instance 'FromJSONKey' Color where
503−-- 'fromJSONKey' = 'genericFromJSONKey' 'defaultJSONKeyOptions'
504−-- @
505−genericFromJSONKey :: forall a. (Generic a, GFromJSONKey (Rep a))
506− => JSONKeyOptions
507− -> FromJSONKeyFunction a
508−genericFromJSONKey opts = FromJSONKeyTextParser $ \t ->
509− case parseSumFromString (keyModifier opts) t of
510− Nothing -> fail $
511− "invalid key " ++ show t ++ ", expected one of " ++ show cnames
512− Just k -> pure (to k)
513− where
514− cnames = unTagged2 (constructorTags (keyModifier opts) :: Tagged2 (Rep a) [String])
515−
516−class (ConstructorNames f, SumFromString f) => GFromJSONKey f where
517−instance (ConstructorNames f, SumFromString f) => GFromJSONKey f where
518−
519402-------------------------------------------------------------------------------
520403-- Functions needed for documentation
521404-------------------------------------------------------------------------------
522405
523406-- | Fail parsing due to a type mismatch, with a descriptive message.
524407--
525−-- The following wrappers should generally be prefered:
526−-- 'withObject', 'withArray', 'withText', 'withBool'.
527−--
528−-- ==== Error message example
408+-- Example usage:
529409--
530−-- > typeMismatch "Object" (String "oops")
531−-- > -- Error: "expected Object, but encountered String"
532−typeMismatch :: String -- ^ The name of the JSON type being parsed
533− -- (@\"Object\"@, @\"Array\"@, @\"String\"@, @\"Number\"@,
534− -- @\"Boolean\"@, or @\"Null\"@).
410+-- @
411+-- instance FromJSON Coord where
412+-- parseJSON ('Object' v) = {- type matches, life is good -}
413+-- parseJSON wat = 'typeMismatch' \"Coord\" wat
414+-- @
415+typeMismatch :: String -- ^ The name of the type you are trying to parse.
535416 -> Value -- ^ The actual value encountered.
536417 -> Parser a
537418typeMismatch expected actual =
538− fail $ "expected " ++ expected ++ ", but encountered " ++ typeOf actual
539−
540−-- | Fail parsing due to a type mismatch, when the expected types are implicit.
541−--
542−-- ==== Error message example
543−--
544−-- > unexpected (String "oops")
545−-- > -- Error: "unexpected String"
546−unexpected :: Value -> Parser a
547−unexpected actual = fail $ "unexpected " ++ typeOf actual
548−
549−-- | JSON type of a value, name of the head constructor.
550−typeOf :: Value -> String
551−typeOf v = case v of
552− Object _ -> "Object"
553− Array _ -> "Array"
554− String _ -> "String"
555− Number _ -> "Number"
556− Bool _ -> "Boolean"
557− Null -> "Null"
419+ fail $ "expected " ++ expected ++ ", encountered " ++ name
420+ where
421+ name = case actual of
422+ Object _ -> "Object"
423+ Array _ -> "Array"
424+ String _ -> "String"
425+ Number _ -> "Number"
426+ Bool _ -> "Boolean"
427+ Null -> "Null"
558428
559429-------------------------------------------------------------------------------
560430-- Lifings of FromJSON and ToJSON to unary and binary type constructors
@@ -567,7 +437,7 @@ typeOf v = case v of
567437--
568438-- * "Data.Aeson.TH" provides Template Haskell functions which will derive an
569439-- instance at compile time. The generated instance is optimized for your type
570−-- so it will probably be more efficient than the following option.
440+-- so will probably be more efficient than the following two options:
571441--
572442-- * The compiler can provide a default generic implementation for
573443-- 'liftParseJSON'.
@@ -585,20 +455,16 @@ typeOf v = case v of
585455--
586456-- data Pair a b = Pair { pairFst :: a, pairSnd :: b } deriving 'Generic1'
587457--
588−-- instance 'FromJSON' a => 'FromJSON1' (Pair a)
458+-- instance FromJSON a => FromJSON1 (Pair a)
589459-- @
590460--
591−-- If the default implementation doesn't give exactly the results you want,
461+-- If @DefaultSignatures@ doesn't give exactly the results you want,
592462-- you can customize the generic decoding with only a tiny amount of
593463-- effort, using 'genericLiftParseJSON' with your preferred 'Options':
594464--
595465-- @
596−-- customOptions = 'defaultOptions'
597−-- { 'fieldLabelModifier' = 'map' 'Data.Char.toUpper'
598−-- }
599−--
600−-- instance 'FromJSON' a => 'FromJSON1' (Pair a) where
601−-- 'liftParseJSON' = 'genericLiftParseJSON' customOptions
466+-- instance FromJSON a => FromJSON1 (Pair a) where
467+-- liftParseJSON = 'genericLiftParseJSON' 'defaultOptions'
602468-- @
603469class FromJSON1 f where
604470 liftParseJSON :: (Value -> Parser a) -> (Value -> Parser [a]) -> Value -> Parser (f a)
@@ -635,8 +501,9 @@ class FromJSON2 f where
635501 -> (Value -> Parser b)
636502 -> (Value -> Parser [b])
637503 -> Value -> Parser [f a b]
638− liftParseJSONList2 fa ga fb gb = withArray "[]" $ \vals ->
639− fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
504+ liftParseJSONList2 fa ga fb gb v = case v of
505+ Array vals -> fmap V.toList (V.mapM (liftParseJSON2 fa ga fb gb) vals)
506+ _ -> typeMismatch "[a]" v
640507
641508-- | Lift the standard 'parseJSON' function through the type constructor.
642509parseJSON2 :: (FromJSON2 f, FromJSON a, FromJSON b) => Value -> Parser (f a b)
@@ -647,10 +514,9 @@ parseJSON2 = liftParseJSON2 parseJSON parseJSONList parseJSON parseJSONList
647514-- List functions
648515-------------------------------------------------------------------------------
649516
650−-- | Helper function to use with 'liftParseJSON'. See 'Data.Aeson.ToJSON.listEncoding'.
651517listParser :: (Value -> Parser a) -> Value -> Parser [a]
652518listParser f (Array xs) = fmap V.toList (V.mapM f xs)
653−listParser _ v = typeMismatch "Array" v
519+listParser _ v = typeMismatch "[a]" v
654520{-# INLINE listParser #-}
655521
656522-------------------------------------------------------------------------------
@@ -668,139 +534,48 @@ instance (FromJSON a) => FromJSON [a] where
668534-- Functions
669535-------------------------------------------------------------------------------
670536
671−-- | Add context to a failure message, indicating the name of the structure
672−-- being parsed.
673−--
674−-- > prependContext "MyType" (fail "[error message]")
675−-- > -- Error: "parsing MyType failed, [error message]"
676−prependContext :: String -> Parser a -> Parser a
677−prependContext name = prependFailure ("parsing " ++ name ++ " failed, ")
678−
679−-- | @'withObject' name f value@ applies @f@ to the 'Object' when @value@
680−-- is an 'Data.Aeson.Object' and fails otherwise.
681−--
682−-- ==== Error message example
683−--
684−-- > withObject "MyType" f (String "oops")
685−-- > -- Error: "parsing MyType failed, expected Object, but encountered String"
537+-- | @withObject expected f value@ applies @f@ to the 'Object' when @value@ is an @Object@
538+-- and fails using @'typeMismatch' expected@ otherwise.
686539withObject :: String -> (Object -> Parser a) -> Value -> Parser a
687−withObject _ f (Object obj) = f obj
688−withObject name _ v = prependContext name (typeMismatch "Object" v)
540+withObject _ f (Object obj) = f obj
541+withObject expected _ v = typeMismatch expected v
689542{-# INLINE withObject #-}
690543
691−-- | @'withText' name f value@ applies @f@ to the 'Text' when @value@ is a
692−-- 'Data.Aeson.String' and fails otherwise.
693−--
694−-- ==== Error message example
695−--
696−-- > withText "MyType" f Null
697−-- > -- Error: "parsing MyType failed, expected String, but encountered Null"
544+-- | @withText expected f value@ applies @f@ to the 'Text' when @value@ is a @String@
545+-- and fails using @'typeMismatch' expected@ otherwise.
698546withText :: String -> (Text -> Parser a) -> Value -> Parser a
699−withText _ f (String txt) = f txt
700−withText name _ v = prependContext name (typeMismatch "String" v)
547+withText _ f (String txt) = f txt
548+withText expected _ v = typeMismatch expected v
701549{-# INLINE withText #-}
702550
703−-- | @'withArray' expected f value@ applies @f@ to the 'Array' when @value@ is
704−-- an 'Data.Aeson.Array' and fails otherwise.
705−--
706−-- ==== Error message example
707−--
708−-- > withArray "MyType" f (String "oops")
709−-- > -- Error: "parsing MyType failed, expected Array, but encountered String"
551+-- | @withArray expected f value@ applies @f@ to the 'Array' when @value@ is an @Array@
552+-- and fails using @'typeMismatch' expected@ otherwise.
710553withArray :: String -> (Array -> Parser a) -> Value -> Parser a
711−withArray _ f (Array arr) = f arr
712−withArray name _ v = prependContext name (typeMismatch "Array" v)
554+withArray _ f (Array arr) = f arr
555+withArray expected _ v = typeMismatch expected v
713556{-# INLINE withArray #-}
714557
715−-- | @'withScientific' name f value@ applies @f@ to the 'Scientific' number
716−-- when @value@ is a 'Data.Aeson.Number' and fails using 'typeMismatch'
717−-- otherwise.
718−--
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.
723−--
724−-- ==== Error message example
725−--
726−-- > withScientific "MyType" f (String "oops")
727−-- > -- Error: "parsing MyType failed, expected Number, but encountered String"
558+-- | @withNumber expected f value@ applies @f@ to the 'Number' when @value@ is a 'Number'.
559+-- and fails using @'typeMismatch' expected@ otherwise.
560+withNumber :: String -> (Number -> Parser a) -> Value -> Parser a
561+withNumber expected f = withScientific expected (f . scientificToNumber)
562+{-# INLINE withNumber #-}
563+{-# DEPRECATED withNumber "Use withScientific instead" #-}
564+
565+-- | @withScientific expected f value@ applies @f@ to the 'Scientific' number when @value@ is a 'Number'.
566+-- and fails using @'typeMismatch' expected@ otherwise.
728567withScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
729−withScientific _ f (Number scientific) = f scientific
730−withScientific name _ v = prependContext name (typeMismatch "Number" v)
568+withScientific _ f (Number scientific) = f scientific
569+withScientific expected _ v = typeMismatch expected v
731570{-# INLINE withScientific #-}
732571
733−-- | A variant of 'withScientific' which doesn't use 'prependContext', so that
734−-- such context can be added separately in a way that also applies when the
735−-- continuation @f :: Scientific -> Parser a@ fails.
736−--
737−-- /Warning/: If you are converting from a scientific to an unbounded
738−-- type such as 'Integer' you may want to add a restriction on the
739−-- size of the exponent (see 'withBoundedScientific') to prevent
740−-- malicious input from filling up the memory of the target system.
741−--
742−-- ==== Error message examples
743−--
744−-- > withScientific' f (String "oops")
745−-- > -- Error: "unexpected String"
746−-- >
747−-- > prependContext "MyType" (withScientific' f (String "oops"))
748−-- > -- Error: "parsing MyType failed, unexpected String"
749−withScientific' :: (Scientific -> Parser a) -> Value -> Parser a
750−withScientific' f v = case v of
751− Number n -> f n
752− _ -> typeMismatch "Number" v
753−{-# INLINE withScientific' #-}
754−
755−-- | @'withBoundedScientific' name f value@ applies @f@ to the 'Scientific' number
756−-- when @value@ is a 'Number' with exponent less than or equal to 1024.
757−withBoundedScientific :: String -> (Scientific -> Parser a) -> Value -> Parser a
758−withBoundedScientific name f v = withBoundedScientific_ (prependContext name) f v
759−{-# INLINE withBoundedScientific #-}
760−
761−-- | A variant of 'withBoundedScientific' which doesn't use 'prependContext',
762−-- so that such context can be added separately in a way that also applies
763−-- when the continuation @f :: Scientific -> Parser a@ fails.
764−withBoundedScientific' :: (Scientific -> Parser a) -> Value -> Parser a
765−withBoundedScientific' f v = withBoundedScientific_ id f v
766−{-# INLINE withBoundedScientific' #-}
767−
768−-- | A variant of 'withBoundedScientific_' parameterized by a function to apply
769−-- to the 'Parser' in case of failure.
770−withBoundedScientific_ :: (Parser a -> Parser a) -> (Scientific -> Parser a) -> Value -> Parser a
771−withBoundedScientific_ whenFail f (Number scientific) =
772− if exp10 > 1024
773− then whenFail (fail msg)
774− else f scientific
775− where
776− exp10 = base10Exponent scientific
777− msg = "found a number with exponent " ++ show exp10 ++ ", but it must not be greater than 1024"
778−withBoundedScientific_ whenFail _ v =
779− whenFail (typeMismatch "Number" v)
780−{-# INLINE withBoundedScientific_ #-}
781−
782−-- | @'withBool' expected f value@ applies @f@ to the 'Bool' when @value@ is a
783−-- 'Boolean' and fails otherwise.
784−--
785−-- ==== Error message example
786−--
787−-- > withBool "MyType" f (String "oops")
788−-- > -- Error: "parsing MyType failed, expected Boolean, but encountered String"
572+-- | @withBool expected f value@ applies @f@ to the 'Bool' when @value@ is a @Bool@
573+-- and fails using @'typeMismatch' expected@ otherwise.
789574withBool :: String -> (Bool -> Parser a) -> Value -> Parser a
790−withBool _ f (Bool arr) = f arr
791−withBool name _ v = prependContext name (typeMismatch "Boolean" v)
575+withBool _ f (Bool arr) = f arr
576+withBool expected _ v = typeMismatch expected v
792577{-# INLINE withBool #-}
793578
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)
798− where
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 #-}
803−
804579-- | Convert a value from JSON, failing if the types do not match.
805580fromJSON :: (FromJSON a) => Value -> Result a
806581fromJSON = parse parseJSON
@@ -819,68 +594,32 @@ ifromJSON = iparse parseJSON
819594-- in an object for it to be valid. If the key and value are
820595-- optional, use '.:?' instead.
821596(.:) :: (FromJSON a) => Object -> Text -> Parser a
822−(.:) = explicitParseField parseJSON
597+obj .: key = case H.lookup key obj of
598+ Nothing -> fail $ "key " ++ show key ++ " not present"
599+ Just v -> parseJSON v <?> Key key
823600{-# INLINE (.:) #-}
824601
825−-- | Retrieve the value associated with the given key of an 'Object'. The
826−-- result is 'Nothing' if the key is not present or if its value is 'Null',
827−-- or 'empty' if the value cannot be converted to the desired type.
602+-- | Retrieve the value associated with the given key of an 'Object'.
603+-- The result is 'Nothing' if the key is not present, or 'empty' if
604+-- the value cannot be converted to the desired type.
828605--
829606-- This accessor is most useful if the key and value can be absent
830607-- from an object without affecting its validity. If the key and
831608-- value are mandatory, use '.:' instead.
832609(.:?) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
833−(.:?) = explicitParseFieldMaybe parseJSON
610+obj .:? key = case H.lookup key obj of
611+ Nothing -> pure Nothing
612+ Just v -> parseJSON v <?> Key key
834613{-# INLINE (.:?) #-}
835614
836−-- | Retrieve the value associated with the given key of an 'Object'.
837−-- The result is 'Nothing' if the key is not present or 'empty' if the
838−-- value cannot be converted to the desired type.
839−--
840−-- This differs from '.:?' by attempting to parse 'Null' the same as any
841−-- other JSON value, instead of interpreting it as 'Nothing'.
615+-- | Like '.:?', but the resulting parser will fail,
616+-- if the key is present but is 'Null'.
842617(.:!) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
843−(.:!) = explicitParseFieldMaybe' parseJSON
618+obj .:! key = case H.lookup key obj of
619+ Nothing -> pure Nothing
620+ Just v -> Just <$> parseJSON v <?> Key key
844621{-# INLINE (.:!) #-}
845622
846−-- | Function variant of '.:'.
847−parseField :: (FromJSON a) => Object -> Text -> Parser a
848−parseField = (.:)
849−{-# INLINE parseField #-}
850−
851−-- | Function variant of '.:?'.
852−parseFieldMaybe :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
853−parseFieldMaybe = (.:?)
854−{-# INLINE parseFieldMaybe #-}
855−
856−-- | Function variant of '.:!'.
857−parseFieldMaybe' :: (FromJSON a) => Object -> Text -> Parser (Maybe a)
858−parseFieldMaybe' = (.:!)
859−{-# INLINE parseFieldMaybe' #-}
860−
861−-- | Variant of '.:' with explicit parser function.
862−--
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 #-}
869−
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 #-}
876−
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 <$> p v <?> Key key
882−{-# INLINE explicitParseFieldMaybe' #-}
883−
884623-- | Helper for use in combination with '.:?' to provide default
885624-- values for optional JSON object fields.
886625--
@@ -903,554 +642,317 @@ pmval .!= val = fromMaybe val <$> pmval
903642-- Generic parseJSON
904643-------------------------------------------------------------------------------
905644
906−instance GFromJSON arity V1 where
907− -- Whereof we cannot format, thereof we cannot parse:
908− gParseJSON _ _ _ = fail "Attempted to parse empty type"
909−
910−
911645instance OVERLAPPABLE_ (GFromJSON arity a) => GFromJSON arity (M1 i c a) where
912646 -- Meta-information, which is not handled elsewhere, is just added to the
913647 -- parsed value:
914− gParseJSON opts fargs = fmap M1 . gParseJSON opts fargs
915−
916−-- Information for error messages
917−
918−type TypeName = String
919−type ConName = String
920−
921−-- | Add the name of the type being parsed to a parser's error messages.
922−contextType :: TypeName -> Parser a -> Parser a
923−contextType = prependContext
924−
925−-- | Add the tagKey that will be looked up while building an ADT
926−-- | Produce the error equivalent to
927−-- | Left "Error in $: parsing T failed, expected an object with keys "tag" and
928−-- | "contents", where "tag" i-- |s associated to one of ["Foo", "Bar"],
929−-- | The parser returned error was: could not find key "tag"
930−contextTag :: Text -> [String] -> Parser a -> Parser a
931−contextTag tagKey cnames = prependFailure
932− ("expected Object with key \"" ++ unpack tagKey ++ "\"" ++
933− " containing one of " ++ show cnames ++ ", ")
934−
935−-- | Add the name of the constructor being parsed to a parser's error messages.
936−contextCons :: ConName -> TypeName -> Parser a -> Parser a
937−contextCons cname tname = prependContext (showCons cname tname)
938−
939−-- | Render a constructor as @\"MyType(MyConstructor)\"@.
940−showCons :: ConName -> TypeName -> String
941−showCons cname tname = tname ++ "(" ++ cname ++ ")"
942−
943−--------------------------------------------------------------------------------
944−
945−-- Parsing single fields
648+ gParseJSON opts pa pj pjl = fmap M1 . gParseJSON opts pa pj pjl
946649
947650instance (FromJSON a) => GFromJSON arity (K1 i a) where
948651 -- Constant values are decoded using their FromJSON instance:
949− gParseJSON _opts _ = fmap K1 . parseJSON
652+ gParseJSON _opts _ _ _ = fmap K1 . parseJSON
950653
951654instance GFromJSON One Par1 where
952655 -- Direct occurrences of the last type parameter are decoded with the
953656 -- function passed in as an argument:
954− gParseJSON _opts (From1Args pj _) = fmap Par1 . pj
657+ gParseJSON _opts _ pj _ = fmap Par1 . pj
955658
956659instance (FromJSON1 f) => GFromJSON One (Rec1 f) where
957660 -- Recursive occurrences of the last type parameter are decoded using their
958661 -- FromJSON1 instance:
959− gParseJSON _opts (From1Args pj pjl) = fmap Rec1 . liftParseJSON pj pjl
662+ gParseJSON _opts _ pj pjl = fmap Rec1 . liftParseJSON pj pjl
663+
664+instance GFromJSON arity U1 where
665+ -- Empty constructors are expected to be encoded as an empty array:
666+ gParseJSON _opts _ _ _ v
667+ | isEmptyArray v = pure U1
668+ | otherwise = typeMismatch "unit constructor (U1)" v
669+
670+instance (ConsFromJSON arity a) => GFromJSON arity (C1 c a) where
671+ -- Constructors need to be decoded differently depending on whether they're
672+ -- a record or not. This distinction is made by consParseJSON:
673+ gParseJSON opts pa pj pjl = fmap M1 . consParseJSON opts pa pj pjl
674+
675+instance ( FromProduct arity a, FromProduct arity b
676+ , ProductSize a, ProductSize b
677+ ) => GFromJSON arity (a :*: b) where
678+ -- Products are expected to be encoded to an array. Here we check whether we
679+ -- got an array of the same size as the product, then parse each of the
680+ -- product's elements using parseProduct:
681+ gParseJSON opts pa pj pjl = withArray "product (:*:)" $ \arr ->
682+ let lenArray = V.length arr
683+ lenProduct = (unTagged2 :: Tagged2 (a :*: b) Int -> Int)
684+ productSize in
685+ if lenArray == lenProduct
686+ then parseProduct opts pa arr 0 lenProduct pj pjl
687+ else fail $ "When expecting a product of " ++ show lenProduct ++
688+ " values, encountered an Array of " ++ show lenArray ++
689+ " elements instead"
690+
691+instance ( AllNullary (a :+: b) allNullary
692+ , ParseSum arity (a :+: b) allNullary
693+ ) => GFromJSON arity (a :+: b) where
694+ -- If all constructors of a sum datatype are nullary and the
695+ -- 'allNullaryToStringTag' option is set they are expected to be
696+ -- encoded as strings. This distinction is made by 'parseSum':
697+ gParseJSON opts pa pj pjl =
698+ (unTagged :: Tagged allNullary (Parser ((a :+: b) d)) ->
699+ (Parser ((a :+: b) d)))
700+ . parseSum opts pa pj pjl
960701
961702instance (FromJSON1 f, GFromJSON One g) => GFromJSON One (f :.: g) where
962703 -- If an occurrence of the last type parameter is nested inside two
963704 -- composed types, it is decoded by using the outermost type's FromJSON1
964705 -- instance to generically decode the innermost type:
965− gParseJSON opts fargs =
966− let gpj = gParseJSON opts fargs in
967− fmap Comp1 . liftParseJSON gpj (listParser gpj)
968−
969−--------------------------------------------------------------------------------
970−
971−instance (GFromJSON' arity a, Datatype d) => GFromJSON arity (D1 d a) where
972− -- Meta-information, which is not handled elsewhere, is just added to the
973− -- parsed value:
974− gParseJSON opts fargs = fmap M1 . gParseJSON' (tname :* opts :* fargs)
975− where
976− tname = moduleName proxy ++ "." ++ datatypeName proxy
977− proxy = undefined :: M1 _i d _f _p
978−
979−-- | 'GFromJSON', after unwrapping the 'D1' constructor, now carrying the data
980−-- type's name.
981−class GFromJSON' arity f where
982− gParseJSON' :: TypeName :* Options :* FromArgs arity a
983− -> Value
984− -> Parser (f a)
985−
986−-- | Single constructor.
987−instance ( ConsFromJSON arity a
988− , AllNullary (C1 c a) allNullary
989− , ParseSum arity (C1 c a) allNullary
990− , Constructor c
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))
997− . parseSum p
998− | otherwise = fmap M1 . consParseJSON (cname :* p)
999− where
1000− cname = conName (undefined :: M1 _i c _f _p)
1001−
1002−-- | Multiple constructors.
1003−instance ( AllNullary (a :+: b) allNullary
1004− , ParseSum arity (a :+: b) allNullary
1005− ) => GFromJSON' arity (a :+: b) where
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':
1009− gParseJSON' p =
1010− (unTagged :: Tagged allNullary (Parser ((a :+: b) _d)) ->
1011− Parser ((a :+: b) _d))
1012− . parseSum p
706+ gParseJSON opts pa pj pjl =
707+ let gpj = gParseJSON opts pa pj pjl in
708+ fmap Comp1 . liftParseJSON gpj (listParser gpj)
1013709
1014710--------------------------------------------------------------------------------
1015711
1016712class ParseSum arity f allNullary where
1017− parseSum :: TypeName :* Options :* FromArgs arity a
1018− -> Value
1019− -> Tagged allNullary (Parser (f a))
1020−
1021−instance ( ConstructorNames f
1022− , SumFromString f
1023− , FromPair arity f
1024− , FromTaggedObject arity f
1025− , FromUntaggedValue arity f
1026− ) => ParseSum arity f True where
1027− parseSum p@(tname :* opts :* _)
1028− | allNullaryToStringTag opts = Tagged . parseAllNullarySum tname opts
1029− | otherwise = Tagged . parseNonAllNullarySum p
1030−
1031−instance ( ConstructorNames f
1032− , FromPair arity f
1033− , FromTaggedObject arity f
1034− , FromUntaggedValue arity f
1035− ) => ParseSum arity f False where
1036− parseSum p = Tagged . parseNonAllNullarySum p
713+ parseSum :: Options -> Proxy arity
714+ -> (Value -> Parser a) -> (Value -> Parser [a])
715+ -> Value -> Tagged allNullary (Parser (f a))
716+
717+instance ( SumFromString (a :+: b)
718+ , FromPair arity (a :+: b)
719+ , FromTaggedObject arity (a :+: b)
720+ ) => ParseSum arity (a :+: b) True where
721+ parseSum opts pa pj pjl
722+ | allNullaryToStringTag opts = Tagged . parseAllNullarySum opts
723+ | otherwise = Tagged . parseNonAllNullarySum opts pa pj pjl
724+
725+instance ( FromPair arity (a :+: b)
726+ , FromTaggedObject arity (a :+: b)
727+ ) => ParseSum arity (a :+: b) False where
728+ parseSum opts pa pj pjl = Tagged . parseNonAllNullarySum opts pa pj pjl
1037729
1038730--------------------------------------------------------------------------------
1039731
1040−parseAllNullarySum :: (SumFromString f, ConstructorNames f)
1041− => TypeName -> Options -> Value -> Parser (f a)
1042−parseAllNullarySum tname opts =
1043− withText tname $ \tag ->
1044− maybe (badTag tag) return $
1045− parseSumFromString modifier tag
1046− where
1047− badTag tag = failWithCTags tname modifier $ \cnames ->
1048− "expected one of the tags " ++ show cnames ++
1049− ", but found tag " ++ show tag
1050− modifier = constructorTagModifier opts
1051−
1052−-- | Fail with an informative error message about a mismatched tag.
1053−-- The error message is parameterized by the list of expected tags,
1054−-- to be inferred from the result type of the parser.
1055−failWithCTags
1056− :: forall f a t. ConstructorNames f
1057− => TypeName -> (String -> t) -> ([t] -> String) -> Parser (f a)
1058−failWithCTags tname modifier f =
1059− contextType tname . fail $ f cnames
1060− where
1061− cnames = unTagged2 (constructorTags modifier :: Tagged2 f [t])
732+parseAllNullarySum :: SumFromString f => Options -> Value -> Parser (f a)
733+parseAllNullarySum opts = withText "Text" $ \key ->
734+ maybe (notFound key) return $
735+ parseSumFromString opts key
1062736
1063737class SumFromString f where
1064− parseSumFromString :: (String -> String) -> Text -> Maybe (f a)
738+ parseSumFromString :: Options -> Text -> Maybe (f a)
1065739
1066740instance (SumFromString a, SumFromString b) => SumFromString (a :+: b) where
1067741 parseSumFromString opts key = (L1 <$> parseSumFromString opts key) <|>
1068742 (R1 <$> parseSumFromString opts key)
1069743
1070744instance (Constructor c) => SumFromString (C1 c U1) where
1071− parseSumFromString modifier key
1072− | key == name = Just $ M1 U1
1073− | otherwise = Nothing
1074− where
1075− name = pack $ modifier $ conName (undefined :: M1 _i c _f _p)
1076−
1077−-- For genericFromJSONKey
1078−instance SumFromString a => SumFromString (D1 d a) where
1079− parseSumFromString modifier key = M1 <$> parseSumFromString modifier key
1080−
1081−-- | List of all constructor tags.
1082−constructorTags :: ConstructorNames a => (String -> t) -> Tagged2 a [t]
1083−constructorTags modifier =
1084− fmap DList.toList (constructorNames' modifier)
1085−
1086−-- | List of all constructor names of an ADT, after a given conversion
1087−-- function. (Better inlining.)
1088−class ConstructorNames a where
1089− constructorNames' :: (String -> t) -> Tagged2 a (DList.DList t)
1090−
1091−instance (ConstructorNames a, ConstructorNames b) => ConstructorNames (a :+: b) where
1092− constructorNames' = liftA2 append constructorNames' constructorNames'
1093− where
1094− append
1095− :: Tagged2 a (DList.DList t)
1096− -> Tagged2 b (DList.DList t)
1097− -> Tagged2 (a :+: b) (DList.DList t)
1098− append (Tagged2 xs) (Tagged2 ys) = Tagged2 (DList.append xs ys)
1099−
1100−instance Constructor c => ConstructorNames (C1 c a) where
1101− constructorNames' f = Tagged2 (pure (f cname))
1102− where
1103− cname = conName (undefined :: M1 _i c _f _p)
1104−
1105−-- For genericFromJSONKey
1106−instance ConstructorNames a => ConstructorNames (D1 d a) where
1107− constructorNames' = retag . constructorNames'
1108− where
1109− retag :: Tagged2 a u -> Tagged2 (D1 d a) u
1110− retag (Tagged2 x) = Tagged2 x
745+ parseSumFromString opts key | key == name = Just $ M1 U1
746+ | otherwise = Nothing
747+ where
748+ name = pack $ constructorTagModifier opts $
749+ conName (undefined :: t c U1 p)
1111750
1112751--------------------------------------------------------------------------------
1113−parseNonAllNullarySum :: forall f c arity.
1114− ( FromPair arity f
1115− , FromTaggedObject arity f
1116− , FromUntaggedValue arity f
1117− , ConstructorNames f
1118− ) => TypeName :* Options :* FromArgs arity c
1119− -> Value -> Parser (f c)
1120−parseNonAllNullarySum p@(tname :* opts :* _) =
752+
753+parseNonAllNullarySum :: ( FromPair arity (a :+: b)
754+ , FromTaggedObject arity (a :+: b)
755+ ) => Options -> Proxy arity
756+ -> (Value -> Parser c) -> (Value -> Parser [c])
757+ -> Value -> Parser ((a :+: b) c)
758+parseNonAllNullarySum opts pa pj pjl =
1121759 case sumEncoding opts of
1122760 TaggedObject{..} ->
1123− withObject tname $ \obj -> do
1124− tag <- contextType tname . contextTag tagKey cnames_ $ obj .: tagKey
1125− fromMaybe (badTag tag <?> Key tagKey) $
1126− parseFromTaggedObject (tag :* contentsFieldName :* p) obj
1127− where
1128− tagKey = pack tagFieldName
1129− badTag tag = failWith_ $ \cnames ->
1130− "expected tag field to be one of " ++ show cnames ++
1131− ", but found tag " ++ show tag
1132− cnames_ = unTagged2 (constructorTags (constructorTagModifier opts) :: Tagged2 f [String])
761+ withObject "Object" $ \obj -> do
762+ tag <- obj .: pack tagFieldName
763+ fromMaybe (notFound tag) $
764+ parseFromTaggedObject opts pa contentsFieldName obj pj pjl tag
1133765
1134766 ObjectWithSingleField ->
1135− withObject tname $ \obj -> case H.toList obj of
1136− [(tag, v)] -> maybe (badTag tag) (<?> Key tag) $
1137− parsePair (tag :* p) v
1138− _ -> contextType tname . fail $
1139− "expected an Object with a single pair, but found " ++
1140− show (H.size obj) ++ " pairs"
1141− where
1142− badTag tag = failWith_ $ \cnames ->
1143− "expected an Object with a single pair where the tag is one of " ++
1144− show cnames ++ ", but found tag " ++ show tag
767+ withObject "Object" $ \obj ->
768+ case H.toList obj of
769+ [pair@(tag, _)] -> fromMaybe (notFound tag) $
770+ parsePair opts pa pj pjl pair
771+ _ -> fail "Object doesn't have a single field"
1145772
1146773 TwoElemArray ->
1147− withArray tname $ \arr -> case V.length arr of
1148− 2 | String tag <- V.unsafeIndex arr 0 ->
1149− maybe (badTag tag <?> Index 0) (<?> Index 1) $
1150− parsePair (tag :* p) (V.unsafeIndex arr 1)
1151− | otherwise ->
1152− contextType tname $
1153− fail "tag element is not a String" <?> Index 0
1154− len -> contextType tname . fail $
1155− "expected a 2-element Array, but encountered an Array of length " ++
1156− show len
1157− where
1158− badTag tag = failWith_ $ \cnames ->
1159− "expected tag of the 2-element Array to be one of " ++
1160− show cnames ++ ", but found tag " ++ show tag
1161−
1162− UntaggedValue -> parseUntaggedValue p
1163− where
1164− failWith_ = failWithCTags tname (constructorTagModifier opts)
774+ withArray "Array" $ \arr ->
775+ if V.length arr == 2
776+ then case V.unsafeIndex arr 0 of
777+ String tag -> fromMaybe (notFound tag) $
778+ parsePair opts pa pj pjl (tag, V.unsafeIndex arr 1)
779+ _ -> fail "First element is not a String"
780+ else fail "Array doesn't have 2 elements"
1165781
1166782--------------------------------------------------------------------------------
1167783
1168784class FromTaggedObject arity f where
1169− -- The first two components of the parameter tuple are: the constructor tag
1170− -- to match against, and the contents field name.
1171− parseFromTaggedObject
1172− :: Text :* String :* TypeName :* Options :* FromArgs arity a
1173− -> Object
1174− -> Maybe (Parser (f a))
785+ parseFromTaggedObject :: Options -> Proxy arity
786+ -> String -> Object
787+ -> (Value -> Parser a) -> (Value -> Parser [a])
788+ -> Text -> Maybe (Parser (f a))
1175789
1176790instance ( FromTaggedObject arity a, FromTaggedObject arity b) =>
1177791 FromTaggedObject arity (a :+: b) where
1178− parseFromTaggedObject p obj =
1179− (fmap L1 <$> parseFromTaggedObject p obj) <|>
1180− (fmap R1 <$> parseFromTaggedObject p obj)
792+ parseFromTaggedObject opts pa contentsFieldName obj pj pjl tag =
793+ (fmap L1 <$> parseFromTaggedObject opts pa contentsFieldName obj pj pjl tag) <|>
794+ (fmap R1 <$> parseFromTaggedObject opts pa contentsFieldName obj pj pjl tag)
1181795
1182−instance ( IsRecord f isRecord
1183− , FromTaggedObject' arity f isRecord
796+instance ( FromTaggedObject' arity f
1184797 , Constructor c
1185798 ) => FromTaggedObject arity (C1 c f) where
1186− parseFromTaggedObject (tag :* contentsFieldName :* p@(_ :* opts :* _))
1187− | tag == tag'
1188− = Just . fmap M1 .
1189− (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
1190− parseFromTaggedObject' (contentsFieldName :* cname :* p)
1191− | otherwise = const Nothing
1192− where
1193− tag' = pack $ constructorTagModifier opts cname
1194− cname = conName (undefined :: M1 _i c _f _p)
799+ parseFromTaggedObject opts pa contentsFieldName obj pj pjl tag
800+ | tag == name = Just $ M1 <$> parseFromTaggedObject'
801+ opts pa contentsFieldName pj pjl obj
802+ | otherwise = Nothing
803+ where
804+ name = pack $ constructorTagModifier opts $
805+ conName (undefined :: t c f p)
1195806
1196807--------------------------------------------------------------------------------
1197808
1198−class FromTaggedObject' arity f isRecord where
1199− -- The first component of the parameter tuple is the contents field name.
1200− parseFromTaggedObject'
1201− :: String :* ConName :* TypeName :* Options :* FromArgs arity a
1202− -> Object -> Tagged isRecord (Parser (f a))
1203−
1204−instance (RecordFromJSON arity f, FieldNames f) => FromTaggedObject' arity f True where
1205− -- Records are unpacked in the tagged object
1206− parseFromTaggedObject' (_ :* p) = Tagged . recordParseJSON (True :* p)
1207−
1208−instance (ConsFromJSON arity f) => FromTaggedObject' arity f False where
1209− -- Nonnullary nonrecords are encoded in the contents field
1210− parseFromTaggedObject' p obj = Tagged $ do
1211− contents <- contextCons cname tname (obj .: key)
1212− consParseJSON p' contents <?> Key key
1213− where
1214− key = pack contentsFieldName
1215− contentsFieldName :* p'@(cname :* tname :* _) = p
809+class FromTaggedObject' arity f where
810+ parseFromTaggedObject' :: Options -> Proxy arity -> String
811+ -> (Value -> Parser a) -> (Value -> Parser [a])
812+ -> Object -> Parser (f a)
813+
814+class FromTaggedObject'' arity f isRecord where
815+ parseFromTaggedObject'' :: Options -> Proxy arity -> String
816+ -> (Value -> Parser a) -> (Value -> Parser [a])
817+ -> Object -> Tagged isRecord (Parser (f a))
818+
819+instance ( IsRecord f isRecord
820+ , FromTaggedObject'' arity f isRecord
821+ ) => FromTaggedObject' arity f where
822+ parseFromTaggedObject' opts pa contentsFieldName pj pjl =
823+ (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a)) .
824+ parseFromTaggedObject'' opts pa contentsFieldName pj pjl
825+
826+instance (FromRecord arity f) => FromTaggedObject'' arity f True where
827+ parseFromTaggedObject'' opts pa _ pj pjl =
828+ Tagged . parseRecord opts pa Nothing pj pjl
1216829
1217−instance OVERLAPPING_ FromTaggedObject' arity U1 False where
1218− -- Nullary constructors don't need a contents field
1219− parseFromTaggedObject' _ _ = Tagged (pure U1)
830+instance (GFromJSON arity f) => FromTaggedObject'' arity f False where
831+ parseFromTaggedObject'' opts pa contentsFieldName pj pjl = Tagged .
832+ (gParseJSON opts pa pj pjl <=< (.: pack contentsFieldName))
833+
834+instance OVERLAPPING_ FromTaggedObject'' arity U1 False where
835+ parseFromTaggedObject'' _ _ _ _ _ _ = Tagged (pure U1)
1220836
1221837--------------------------------------------------------------------------------
1222838
1223−-- | Constructors need to be decoded differently depending on whether they're
1224−-- a record or not. This distinction is made by 'ConsParseJSON'.
1225839class ConsFromJSON arity f where
1226− consParseJSON
1227− :: ConName :* TypeName :* Options :* FromArgs arity a
1228− -> Value -> Parser (f a)
840+ consParseJSON :: Options -> Proxy arity
841+ -> (Value -> Parser a) -> (Value -> Parser [a])
842+ -> Value -> Parser (f a)
1229843
1230844class ConsFromJSON' arity f isRecord where
1231− consParseJSON'
1232− :: ConName :* TypeName :* Options :* FromArgs arity a
1233− -> Value -> Tagged isRecord (Parser (f a))
845+ consParseJSON' :: Options -> Proxy arity
846+ -> (Maybe Text) -- ^ A dummy label
847+ -- (Nothing to use proper label)
848+ -> (Value -> Parser a) -> (Value -> Parser [a])
849+ -> Value -> Tagged isRecord (Parser (f a))
1234850
1235851instance ( IsRecord f isRecord
1236852 , ConsFromJSON' arity f isRecord
1237853 ) => ConsFromJSON arity f where
1238− consParseJSON p =
1239− (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a))
1240− . consParseJSON' p
1241−
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))
1248−
1249−instance RecordFromJSON arity f => ConsFromJSON' arity f True where
1250− consParseJSON' p@(cname :* tname :* _) =
1251− Tagged . withObject (showCons cname tname) (recordParseJSON (False :* p))
1252−
1253−instance OVERLAPPING_
1254− ConsFromJSON' arity U1 False where
1255− -- Empty constructors are expected to be encoded as an empty array:
1256− consParseJSON' (cname :* tname :* _) v =
1257− Tagged . contextCons cname tname $ case v of
1258− Array a | V.null a -> pure U1
1259− | otherwise -> fail_ a
1260− _ -> typeMismatch "Array" v
1261− where
1262− fail_ a = fail $
1263− "expected an empty Array, but encountered an Array of length " ++
1264− show (V.length a)
854+ consParseJSON opts pa pj pjl v = let
855+ (v2,lab) = case (unwrapUnaryRecords opts,isUnary (undefined :: f a)) of
856+ -- use a dummy object with a dummy label
857+ (True,True) -> ((object [(pack "dummy",v)]),Just $ pack "dummy")
858+ _ ->(v,Nothing)
859+ in (unTagged :: Tagged isRecord (Parser (f a)) -> Parser (f a))
860+ $ consParseJSON' opts pa lab pj pjl v2
1265861
1266−instance OVERLAPPING_
1267− GFromJSON arity f => ConsFromJSON' arity (S1 s f) False where
1268− consParseJSON' (_ :* _ :* opts :* fargs) =
1269− Tagged . fmap M1 . gParseJSON opts fargs
1270862
1271−instance (ProductFromJSON arity f, ProductSize f
1272− ) => ConsFromJSON' arity f False where
1273− consParseJSON' p = Tagged . productParseJSON0 p
1274−
1275−--------------------------------------------------------------------------------
863+instance (FromRecord arity f) => ConsFromJSON' arity f True where
864+ consParseJSON' opts pa mlab pj pjl = Tagged . (withObject "record (:*:)"
865+ $ parseRecord opts pa mlab pj pjl)
1276866
1277−class FieldNames f where
1278− fieldNames :: f a -> [Text] -> [Text]
867+instance (GFromJSON arity f) => ConsFromJSON' arity f False where
868+ consParseJSON' opts pa _ pj pjl = Tagged . gParseJSON opts pa pj pjl
1279869
1280−instance (FieldNames a, FieldNames b) => FieldNames (a :*: b) where
1281− fieldNames _ =
1282− fieldNames (undefined :: a x) .
1283− fieldNames (undefined :: b y)
1284−
1285−instance (Selector s) => FieldNames (S1 s f) where
1286− fieldNames _ = (pack (selName (undefined :: M1 _i s _f _p)) :)
1287−
1288−class RecordFromJSON arity f where
1289− recordParseJSON
1290− :: Bool :* ConName :* TypeName :* Options :* FromArgs arity a
1291− -> Object -> Parser (f a)
870+--------------------------------------------------------------------------------
1292871
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
872+class FromRecord arity f where
873+ parseRecord :: Options -> Proxy arity
874+ -> (Maybe Text) -- ^ A dummy label
875+ -- (Nothing to use proper label)
876+ -> (Value -> Parser a) -> (Value -> Parser [a])
877+ -> Object -> Parser (f a)
878+
879+instance ( FromRecord arity a
880+ , FromRecord arity b
881+ ) => FromRecord arity (a :*: b) where
882+ parseRecord opts pa _ pj pjl obj =
883+ (:*:) <$> parseRecord opts pa Nothing pj pjl obj
884+ <*> parseRecord opts pa Nothing pj pjl obj
885+
886+instance ( Selector s
887+ , GFromJSON arity a
888+ ) => FromRecord arity (S1 s a) where
889+ parseRecord opts pa lab pj pjl =
890+ (<?> Key label) . gParseJSON opts pa pj pjl <=< (.: label)
1298891 where
1299− knownFields :: H.HashMap Text ()
1300− knownFields = H.fromList $ map (,()) $
1301− fieldNames (undefined :: f a)
1302− [pack (tagFieldName (sumEncoding opts)) | fromTaggedSum]
1303− checkUnknown =
1304− if not (rejectUnknownFields opts)
1305− then \_ -> return ()
1306− else \obj -> case H.keys (H.difference obj knownFields) of
1307− [] -> return ()
1308− unknownFields -> contextCons cname tname $
1309− fail ("unknown fields: " ++ show unknownFields)
1310−
1311−class RecordFromJSON' arity f where
1312− recordParseJSON'
1313− :: ConName :* TypeName :* Options :* FromArgs arity a
1314− -> Object -> Parser (f a)
1315−
1316−instance ( RecordFromJSON' arity a
1317− , RecordFromJSON' arity b
1318− ) => RecordFromJSON' arity (a :*: b) where
1319− recordParseJSON' p obj =
1320− (:*:) <$> recordParseJSON' p obj
1321− <*> recordParseJSON' p obj
1322−
1323−instance OVERLAPPABLE_ (Selector s, GFromJSON arity a) =>
1324− RecordFromJSON' arity (S1 s a) where
1325− recordParseJSON' (cname :* tname :* opts :* fargs) obj = do
1326− fv <- contextCons cname tname (obj .: label)
1327− M1 <$> gParseJSON opts fargs fv <?> Key label
1328− where
1329− label = pack $ fieldLabelModifier opts sname
1330− sname = selName (undefined :: M1 _i s _f _p)
1331−
1332−instance INCOHERENT_ (Selector s, FromJSON a) =>
1333− RecordFromJSON' arity (S1 s (K1 i (Maybe a))) where
1334− recordParseJSON' (_ :* _ :* opts :* _) obj = M1 . K1 <$> obj .:? pack label
1335− where
1336− label = fieldLabelModifier opts sname
1337− sname = selName (undefined :: M1 _i s _f _p)
1338−
1339−-- Parse an Option like a Maybe.
1340−instance INCOHERENT_ (Selector s, FromJSON a) =>
1341− RecordFromJSON' arity (S1 s (K1 i (Semigroup.Option a))) where
1342− recordParseJSON' p obj = wrap <$> recordParseJSON' p obj
1343− where
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))
892+ label = fromMaybe defLabel lab
893+ defLabel = pack . fieldLabelModifier opts $
894+ selName (undefined :: t s a p)
895+
896+instance OVERLAPPING_ (Selector s, FromJSON a) =>
897+ FromRecord arity (S1 s (K1 i (Maybe a))) where
898+ parseRecord _ _ (Just lab) _ _ obj = (M1 . K1) <$> obj .:? lab
899+ parseRecord opts _ Nothing _ _ obj = (M1 . K1) <$> obj .:? pack label
900+ where
901+ label = fieldLabelModifier opts $
902+ selName (undefined :: t s (K1 i (Maybe a)) p)
1346903
1347904--------------------------------------------------------------------------------
1348905
1349−productParseJSON0
1350− :: forall f arity a. (ProductFromJSON arity f, ProductSize f)
1351− => ConName :* TypeName :* Options :* FromArgs arity a
1352− -> Value -> Parser (f a)
1353− -- Products are expected to be encoded to an array. Here we check whether we
1354− -- got an array of the same size as the product, then parse each of the
1355− -- product's elements using productParseJSON:
1356−productParseJSON0 p@(cname :* tname :* _ :* _) =
1357− withArray (showCons cname tname) $ \arr ->
1358− let lenArray = V.length arr
1359− lenProduct = (unTagged2 :: Tagged2 f Int -> Int)
1360− productSize in
1361− if lenArray == lenProduct
1362− then productParseJSON p arr 0 lenProduct
1363− else contextCons cname tname $
1364− fail $ "expected an Array of length " ++ show lenProduct ++
1365− ", but encountered an Array of length " ++ show lenArray
1366−
1367−--
1368−
1369−class ProductFromJSON arity f where
1370− productParseJSON :: ConName :* TypeName :* Options :* FromArgs arity a
906+class FromProduct arity f where
907+ parseProduct :: Options -> Proxy arity
1371908 -> Array -> Int -> Int
909+ -> (Value -> Parser a) -> (Value -> Parser [a])
1372910 -> Parser (f a)
1373911
1374−instance ( ProductFromJSON arity a
1375− , ProductFromJSON arity b
1376− ) => ProductFromJSON arity (a :*: b) where
1377− productParseJSON p arr ix len =
1378− (:*:) <$> productParseJSON p arr ix lenL
1379− <*> productParseJSON p arr ixR lenR
912+instance ( FromProduct arity a
913+ , FromProduct arity b
914+ ) => FromProduct arity (a :*: b) where
915+ parseProduct opts pa arr ix len pj pjl =
916+ (:*:) <$> parseProduct opts pa arr ix lenL pj pjl
917+ <*> parseProduct opts pa arr ixR lenR pj pjl
1380918 where
1381919 lenL = len `unsafeShiftR` 1
1382920 ixR = ix + lenL
1383921 lenR = len - lenL
1384922
1385−instance (GFromJSON arity a) => ProductFromJSON arity (S1 s a) where
1386− productParseJSON (_ :* _ :* opts :* fargs) arr ix _ =
1387− M1 <$> gParseJSON opts fargs (V.unsafeIndex arr ix) <?> Index ix
923+instance (GFromJSON arity a) => FromProduct arity (S1 s a) where
924+ parseProduct opts pa arr ix _ pj pjl =
925+ gParseJSON opts pa pj pjl $ V.unsafeIndex arr ix
1388926
1389927--------------------------------------------------------------------------------
1390928
1391929class FromPair arity f where
1392− -- The first component of the parameter tuple is the tag to match.
1393− parsePair :: Text :* TypeName :* Options :* FromArgs arity a
1394− -> Value
1395− -> Maybe (Parser (f a))
930+ parsePair :: Options -> Proxy arity
931+ -> (Value -> Parser a) -> (Value -> Parser [a])
932+ -> Pair -> Maybe (Parser (f a))
1396933
1397934instance ( FromPair arity a
1398935 , FromPair arity b
1399936 ) => FromPair arity (a :+: b) where
1400− parsePair p pair =
1401− (fmap L1 <$> parsePair p pair) <|>
1402− (fmap R1 <$> parsePair p pair)
937+ parsePair opts pa pj pjl pair = (fmap L1 <$> parsePair opts pa pj pjl pair) <|>
938+ (fmap R1 <$> parsePair opts pa pj pjl pair)
1403939
1404940instance ( Constructor c
941+ , GFromJSON arity a
1405942 , ConsFromJSON arity a
1406943 ) => FromPair arity (C1 c a) where
1407− parsePair (tag :* p@(_ :* opts :* _)) v
1408− | tag == tag' = Just $ M1 <$> consParseJSON (cname :* p) v
944+ parsePair opts pa pj pjl (tag, value)
945+ | tag == tag' = Just $ gParseJSON opts pa pj pjl value
1409946 | otherwise = Nothing
1410− where
1411− tag' = pack $ constructorTagModifier opts cname
1412− cname = conName (undefined :: M1 _i c _a _p)
947+ where
948+ tag' = pack $ constructorTagModifier opts $
949+ conName (undefined :: t c a p)
1413950
1414951--------------------------------------------------------------------------------
1415952
1416−class FromUntaggedValue arity f where
1417− parseUntaggedValue :: TypeName :* Options :* FromArgs arity a
1418− -> Value
1419− -> Parser (f a)
1420−
1421−instance
1422− ( FromUntaggedValue arity a
1423− , FromUntaggedValue arity b
1424− ) => FromUntaggedValue arity (a :+: b)
1425− where
1426− parseUntaggedValue p value =
1427− L1 <$> parseUntaggedValue p value <|>
1428− R1 <$> parseUntaggedValue p value
1429−
1430−instance OVERLAPPABLE_
1431− ( ConsFromJSON arity a
1432− , Constructor c
1433− ) => FromUntaggedValue arity (C1 c a)
1434− where
1435− parseUntaggedValue p = fmap M1 . consParseJSON (cname :* p)
1436− where
1437− cname = conName (undefined :: M1 _i c _f _p)
1438−
1439−instance OVERLAPPING_
1440− ( Constructor c )
1441− => FromUntaggedValue arity (C1 c U1)
1442− where
1443− parseUntaggedValue (tname :* opts :* _) v =
1444− contextCons cname tname $ case v of
1445− String tag
1446− | tag == tag' -> pure $ M1 U1
1447− | otherwise -> fail_ tag
1448− _ -> typeMismatch "String" v
1449− where
1450− tag' = pack $ constructorTagModifier opts cname
1451− cname = conName (undefined :: M1 _i c _f _p)
1452− fail_ tag = fail $
1453− "expected tag " ++ show tag' ++ ", but found tag " ++ show tag
953+notFound :: Text -> Parser a
954+notFound key = fail $ "The key \"" ++ unpack key ++ "\" was not found"
955+{-# INLINE notFound #-}
1454956
1455957-------------------------------------------------------------------------------
1456958-- Instances
@@ -1489,10 +991,6 @@ instance FromJSON2 Either where
1489991 liftParseJSON2 pA _ pB _ (Object (H.toList -> [(key, value)]))
1490992 | key == left = Left <$> pA value <?> Key left
1491993 | key == right = Right <$> pB value <?> Key right
1492− where
1493− left, right :: Text
1494− left = "Left"
1495− right = "Right"
1496994
1497995 liftParseJSON2 _ _ _ _ _ = fail $
1498996 "expected an object with a single property " ++
@@ -1508,20 +1006,20 @@ instance (FromJSON a, FromJSON b) => FromJSON (Either a b) where
15081006 parseJSON = parseJSON2
15091007 {-# INLINE parseJSON #-}
15101008
1511−instance FromJSON Void where
1512− parseJSON _ = fail "Cannot parse Void"
1513− {-# INLINE parseJSON #-}
1009+left, right :: Text
1010+left = "Left"
1011+right = "Right"
1012+
15141013
15151014instance FromJSON Bool where
1516− parseJSON (Bool b) = pure b
1517− parseJSON v = typeMismatch "Bool" v
1015+ parseJSON = withBool "Bool" pure
15181016 {-# INLINE parseJSON #-}
15191017
15201018instance FromJSONKey Bool where
15211019 fromJSONKey = FromJSONKeyTextParser $ \t -> case t of
15221020 "true" -> pure True
15231021 "false" -> pure False
1524− _ -> fail $ "cannot parse key " ++ show t ++ " into Bool"
1022+ _ -> fail $ "Cannot parse key into Bool: " ++ T.unpack t
15251023
15261024instance FromJSON Ordering where
15271025 parseJSON = withText "Ordering" $ \s ->
@@ -1529,30 +1027,25 @@ instance FromJSON Ordering where
15291027 "LT" -> return LT
15301028 "EQ" -> return EQ
15311029 "GT" -> return GT
1532− _ -> fail $ "parsing Ordering failed, unexpected " ++ show s ++
1533− " (expected \"LT\", \"EQ\", or \"GT\")"
1030+ _ -> fail "Parsing Ordering value failed: expected \"LT\", \"EQ\", or \"GT\""
15341031
15351032instance FromJSON () where
15361033 parseJSON = withArray "()" $ \v ->
15371034 if V.null v
15381035 then pure ()
1539− else prependContext "()" $ fail "expected an empty array"
1036+ else fail "Expected an empty array"
15401037 {-# INLINE parseJSON #-}
15411038
15421039instance FromJSON Char where
1543− parseJSON = withText "Char" parseChar
1040+ parseJSON = withText "Char" $ \t ->
1041+ if T.compareLength t 1 == EQ
1042+ then pure $ T.head t
1043+ else fail "Expected a string of length 1"
15441044 {-# INLINE parseJSON #-}
15451045
1546− parseJSONList (String s) = pure (T.unpack s)
1547− parseJSONList v = typeMismatch "String" v
1046+ parseJSONList = withText "String" $ pure . T.unpack
15481047 {-# INLINE parseJSONList #-}
15491048
1550−parseChar :: Text -> Parser Char
1551−parseChar t =
1552− if T.compareLength t 1 == EQ
1553− then pure $ T.head t
1554− else prependContext "Char" $ fail "expected a string of length 1"
1555−
15561049instance FromJSON Double where
15571050 parseJSON = parseRealFloat "Double"
15581051 {-# INLINE parseJSON #-}
@@ -1564,6 +1057,12 @@ instance FromJSONKey Double where
15641057 "-Infinity" -> pure (negate 1/0)
15651058 _ -> Scientific.toRealFloat <$> parseScientificText t
15661059
1060+instance FromJSON Number where
1061+ parseJSON (Number s) = pure $ scientificToNumber s
1062+ parseJSON Null = pure (D (0/0))
1063+ parseJSON v = typeMismatch "Number" v
1064+ {-# INLINE parseJSON #-}
1065+
15671066instance FromJSON Float where
15681067 parseJSON = parseRealFloat "Float"
15691068 {-# INLINE parseJSON #-}
@@ -1576,133 +1075,112 @@ instance FromJSONKey Float where
15761075 _ -> Scientific.toRealFloat <$> parseScientificText t
15771076
15781077instance (FromJSON a, Integral a) => FromJSON (Ratio a) where
1579− parseJSON (Number x)
1580− | exp10 <= 1024
1581− , exp10 >= -1024 = return $! realToFrac x
1582− | otherwise = prependContext "Ratio" $ fail msg
1583− where
1584− exp10 = base10Exponent x
1585− msg = "found a number with exponent " ++ show exp10
1586− ++ ", but it must not be greater than 1024 or less than -1024"
1587− parseJSON o = objParser o
1588− where
1589− objParser = withObject "Rational" $ \obj -> do
1590− numerator <- obj .: "numerator"
1591− denominator <- obj .: "denominator"
1592− if denominator == 0
1593− then fail "Ratio denominator was 0"
1594− else pure $ numerator % denominator
1078+ parseJSON = withObject "Rational" $ \obj ->
1079+ (%) <$> obj .: "numerator"
1080+ <*> obj .: "denominator"
15951081 {-# INLINE parseJSON #-}
15961082
1597−-- | This instance includes a bounds check to prevent maliciously
1598−-- large inputs to fill up the memory of the target system. You can
1599−-- newtype 'Scientific' and provide your own instance using
1600−-- 'withScientific' if you want to allow larger inputs.
1083+-- | /WARNING:/ Only parse fixed-precision numbers from trusted input
1084+-- since an attacker could easily fill up the memory of the target
1085+-- system by specifying a scientific number with a big exponent like
1086+-- @1e1000000000@.
16011087instance HasResolution a => FromJSON (Fixed a) where
1602− parseJSON = prependContext "Fixed" . withBoundedScientific' (pure . realToFrac)
1088+ parseJSON = withScientific "Fixed" $ pure . realToFrac
16031089 {-# INLINE parseJSON #-}
16041090
16051091instance FromJSON Int where
1606− parseJSON = parseBoundedIntegral "Int"
1092+ parseJSON = parseIntegral "Int"
16071093 {-# INLINE parseJSON #-}
16081094
16091095instance FromJSONKey Int where
1610− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int"
1096+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16111097
1612−-- | This instance includes a bounds check to prevent maliciously
1613−-- large inputs to fill up the memory of the target system. You can
1614−-- newtype 'Scientific' and provide your own instance using
1615−-- 'withScientific' if you want to allow larger inputs.
1098+-- | /WARNING:/ Only parse Integers from trusted input since an
1099+-- attacker could easily fill up the memory of the target system by
1100+-- specifying a scientific number with a big exponent like
1101+-- @1e1000000000@.
16161102instance FromJSON Integer where
1617− parseJSON = parseIntegral "Integer"
1103+ parseJSON = withScientific "Integral" $ pure . truncate
16181104 {-# INLINE parseJSON #-}
16191105
16201106instance FromJSONKey Integer where
1621− fromJSONKey = FromJSONKeyTextParser $ parseIntegralText "Integer"
1107+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16221108
16231109instance FromJSON Natural where
1624− parseJSON value = do
1625− integer <- parseIntegral "Natural" value
1626− parseNatural integer
1110+ parseJSON = withScientific "Natural" $ \s ->
1111+ if Scientific.coefficient s < 0
1112+ then fail $ "Expected a Natural number but got the negative number: " <> show s
1113+ else pure $ truncate s
16271114
16281115instance FromJSONKey Natural where
1629− fromJSONKey = FromJSONKeyTextParser $ \text -> do
1630− integer <- parseIntegralText "Natural" text
1631− parseNatural integer
1632−
1633−parseNatural :: Integer -> Parser Natural
1634−parseNatural integer =
1635− if integer < 0 then
1636− fail $ "parsing Natural failed, unexpected negative number " <> show integer
1637− else
1638− pure $ fromIntegral integer
1116+ fromJSONKey = FromJSONKeyTextParser $ \t -> parseScientificText t >>= \s ->
1117+ if Scientific.coefficient s < 0
1118+ then fail $ "Expected a Natural number but got the negative number: " <> show s
1119+ else pure $ truncate s
16391120
16401121instance FromJSON Int8 where
1641− parseJSON = parseBoundedIntegral "Int8"
1122+ parseJSON = parseIntegral "Int8"
16421123 {-# INLINE parseJSON #-}
16431124
16441125instance FromJSONKey Int8 where
1645− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int8"
1126+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16461127
16471128instance FromJSON Int16 where
1648− parseJSON = parseBoundedIntegral "Int16"
1129+ parseJSON = parseIntegral "Int16"
16491130 {-# INLINE parseJSON #-}
16501131
16511132instance FromJSONKey Int16 where
1652− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int16"
1133+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16531134
16541135instance FromJSON Int32 where
1655− parseJSON = parseBoundedIntegral "Int32"
1136+ parseJSON = parseIntegral "Int32"
16561137 {-# INLINE parseJSON #-}
16571138
16581139instance FromJSONKey Int32 where
1659− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int32"
1140+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16601141
16611142instance FromJSON Int64 where
1662− parseJSON = parseBoundedIntegral "Int64"
1143+ parseJSON = parseIntegral "Int64"
16631144 {-# INLINE parseJSON #-}
16641145
16651146instance FromJSONKey Int64 where
1666− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Int64"
1147+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16671148
16681149instance FromJSON Word where
1669− parseJSON = parseBoundedIntegral "Word"
1150+ parseJSON = parseIntegral "Word"
16701151 {-# INLINE parseJSON #-}
16711152
16721153instance FromJSONKey Word where
1673− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word"
1154+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16741155
16751156instance FromJSON Word8 where
1676− parseJSON = parseBoundedIntegral "Word8"
1157+ parseJSON = parseIntegral "Word8"
16771158 {-# INLINE parseJSON #-}
16781159
16791160instance FromJSONKey Word8 where
1680− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word8"
1161+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16811162
16821163instance FromJSON Word16 where
1683− parseJSON = parseBoundedIntegral "Word16"
1164+ parseJSON = parseIntegral "Word16"
16841165 {-# INLINE parseJSON #-}
16851166
16861167instance FromJSONKey Word16 where
1687− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word16"
1168+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16881169
16891170instance FromJSON Word32 where
1690− parseJSON = parseBoundedIntegral "Word32"
1171+ parseJSON = parseIntegral "Word32"
16911172 {-# INLINE parseJSON #-}
16921173
16931174instance FromJSONKey Word32 where
1694− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word32"
1175+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
16951176
16961177instance FromJSON Word64 where
1697− parseJSON = parseBoundedIntegral "Word64"
1178+ parseJSON = parseIntegral "Word64"
16981179 {-# INLINE parseJSON #-}
16991180
17001181instance FromJSONKey Word64 where
1701− fromJSONKey = FromJSONKeyTextParser $ parseBoundedIntegralText "Word64"
1182+ fromJSONKey = FromJSONKeyTextParser parseIntegralText
17021183
1703−instance FromJSON CTime where
1704− parseJSON = fmap CTime . parseJSON
1705− {-# INLINE parseJSON #-}
17061184
17071185instance FromJSON Text where
17081186 parseJSON = withText "Text" pure
@@ -1732,17 +1210,17 @@ parseVersionText = go . readP_to_S parseVersion . unpack
17321210 where
17331211 go [(v,[])] = return v
17341212 go (_ : xs) = go xs
1735− go _ = fail "parsing Version failed"
1213+ go _ = fail $ "could not parse Version"
17361214
17371215-------------------------------------------------------------------------------
17381216-- semigroups NonEmpty
17391217-------------------------------------------------------------------------------
17401218
17411219instance FromJSON1 NonEmpty where
1742− liftParseJSON p _ = withArray "NonEmpty" $
1220+ liftParseJSON p _ = withArray "NonEmpty a" $
17431221 (>>= ne) . Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
17441222 where
1745− ne [] = fail "parsing NonEmpty failed, unexpected empty list"
1223+ ne [] = fail "Expected a NonEmpty but got an empty list"
17461224 ne (x:xs) = pure (x :| xs)
17471225 {-# INLINE liftParseJSON #-}
17481226
@@ -1763,7 +1241,7 @@ instance FromJSON Scientific where
17631241-------------------------------------------------------------------------------
17641242
17651243instance FromJSON1 DList.DList where
1766− liftParseJSON p _ = withArray "DList" $
1244+ liftParseJSON p _ = withArray "DList a" $
17671245 fmap DList.fromList .
17681246 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
17691247 {-# INLINE liftParseJSON #-}
@@ -1790,7 +1268,7 @@ instance (FromJSON a) => FromJSON (Identity a) where
17901268 parseJSONList = liftParseJSONList parseJSON parseJSONList
17911269 {-# INLINE parseJSONList #-}
17921270
1793−instance (FromJSONKey a) => FromJSONKey (Identity a) where
1271+instance (FromJSONKey a, FromJSON a) => FromJSONKey (Identity a) where
17941272 fromJSONKey = coerceFromJSONKeyFunction (fromJSONKey :: FromJSONKeyFunction a)
17951273 fromJSONKeyList = coerceFromJSONKeyFunction (fromJSONKeyList :: FromJSONKeyFunction [a])
17961274
@@ -1815,46 +1293,12 @@ instance (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Compose f g a) wher
18151293 parseJSONList = liftParseJSONList parseJSON parseJSONList
18161294 {-# INLINE parseJSONList #-}
18171295
1818−
1819−instance (FromJSON1 f, FromJSON1 g) => FromJSON1 (Product f g) where
1820− liftParseJSON p pl a = uncurry Pair <$> liftParseJSON2 px pxl py pyl a
1821− where
1822− px = liftParseJSON p pl
1823− pxl = liftParseJSONList p pl
1824− py = liftParseJSON p pl
1825− pyl = liftParseJSONList p pl
1826− {-# INLINE liftParseJSON #-}
1827−
1828−instance (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Product f g a) where
1829− parseJSON = parseJSON1
1830− {-# INLINE parseJSON #-}
1831−
1832−
1833−instance (FromJSON1 f, FromJSON1 g) => FromJSON1 (Sum f g) where
1834− liftParseJSON p pl (Object (H.toList -> [(key, value)]))
1835− | key == inl = InL <$> liftParseJSON p pl value <?> Key inl
1836− | key == inr = InR <$> liftParseJSON p pl value <?> Key inl
1837− where
1838− inl, inr :: Text
1839− inl = "InL"
1840− inr = "InR"
1841−
1842− liftParseJSON _ _ _ = fail $
1843− "parsing Sum failed, expected an object with a single property " ++
1844− "where the property key should be either " ++
1845− "\"InL\" or \"InR\""
1846− {-# INLINE liftParseJSON #-}
1847−
1848−instance (FromJSON1 f, FromJSON1 g, FromJSON a) => FromJSON (Sum f g a) where
1849− parseJSON = parseJSON1
1850− {-# INLINE parseJSON #-}
1851−
18521296-------------------------------------------------------------------------------
18531297-- containers
18541298-------------------------------------------------------------------------------
18551299
18561300instance FromJSON1 Seq.Seq where
1857− liftParseJSON p _ = withArray "Seq" $
1301+ liftParseJSON p _ = withArray "Seq a" $
18581302 fmap Seq.fromList .
18591303 Tr.sequence . zipWith (parseIndexedJSON p) [0..] . V.toList
18601304 {-# INLINE liftParseJSON #-}
@@ -1888,15 +1332,15 @@ instance FromJSON a => FromJSON (IntMap.IntMap a) where
18881332
18891333instance (FromJSONKey k, Ord k) => FromJSON1 (M.Map k) where
18901334 liftParseJSON p _ = case fromJSONKey of
1891− FromJSONKeyCoerce _ -> withObject "Map" $
1335+ FromJSONKeyCoerce _-> withObject "Map k v" $
18921336 fmap (H.foldrWithKey (M.insert . unsafeCoerce) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1893− FromJSONKeyText f -> withObject "Map" $
1337+ FromJSONKeyText f -> withObject "Map k v" $
18941338 fmap (H.foldrWithKey (M.insert . f) M.empty) . H.traverseWithKey (\k v -> p v <?> Key k)
1895− FromJSONKeyTextParser f -> withObject "Map" $
1339+ FromJSONKeyTextParser f -> withObject "Map k v" $
18961340 H.foldrWithKey (\k v m -> M.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure M.empty)
1897− FromJSONKeyValue f -> withArray "Map" $ \arr ->
1898− fmap M.fromList . Tr.sequence .
1899− zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
1341+ FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
1342+ M.fromList <$> (Tr.sequence .
1343+ zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr)
19001344 {-# INLINE liftParseJSON #-}
19011345
19021346instance (FromJSONKey k, Ord k, FromJSON v) => FromJSON (M.Map k v) where
@@ -1916,24 +1360,12 @@ instance (FromJSON v) => FromJSON (Tree.Tree v) where
19161360 parseJSON = parseJSON1
19171361 {-# INLINE parseJSON #-}
19181362
1919−-------------------------------------------------------------------------------
1920−-- uuid
1921−-------------------------------------------------------------------------------
1922−
1923−instance FromJSON UUID.UUID where
1924− parseJSON = withText "UUID" $
1925− maybe (fail "invalid UUID") pure . UUID.fromText
1926−
1927−instance FromJSONKey UUID.UUID where
1928− fromJSONKey = FromJSONKeyTextParser $
1929− maybe (fail "invalid UUID") pure . UUID.fromText
1930−
19311363-------------------------------------------------------------------------------
19321364-- vector
19331365-------------------------------------------------------------------------------
19341366
19351367instance FromJSON1 Vector where
1936− liftParseJSON p _ = withArray "Vector" $
1368+ liftParseJSON p _ = withArray "Vector a" $
19371369 V.mapM (uncurry $ parseIndexedJSON p) . V.indexed
19381370 {-# INLINE liftParseJSON #-}
19391371
@@ -1947,14 +1379,14 @@ vectorParseJSON s = withArray s $ fmap V.convert . V.mapM (uncurry $ parseIndexe
19471379{-# INLINE vectorParseJSON #-}
19481380
19491381instance (Storable a, FromJSON a) => FromJSON (VS.Vector a) where
1950− parseJSON = vectorParseJSON "Data.Vector.Storable.Vector"
1382+ parseJSON = vectorParseJSON "Data.Vector.Storable.Vector a"
19511383
19521384instance (VP.Prim a, FromJSON a) => FromJSON (VP.Vector a) where
1953− parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector"
1385+ parseJSON = vectorParseJSON "Data.Vector.Primitive.Vector a"
19541386 {-# INLINE parseJSON #-}
19551387
19561388instance (VG.Vector VU.Vector a, FromJSON a) => FromJSON (VU.Vector a) where
1957− parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector"
1389+ parseJSON = vectorParseJSON "Data.Vector.Unboxed.Vector a"
19581390 {-# INLINE parseJSON #-}
19591391
19601392-------------------------------------------------------------------------------
@@ -1968,15 +1400,15 @@ instance (Eq a, Hashable a, FromJSON a) => FromJSON (HashSet.HashSet a) where
19681400
19691401instance (FromJSONKey k, Eq k, Hashable k) => FromJSON1 (H.HashMap k) where
19701402 liftParseJSON p _ = case fromJSONKey of
1971− FromJSONKeyCoerce _ -> withObject "HashMap ~Text" $
1403+ FromJSONKeyCoerce _ -> withObject "HashMap ~Text v" $
19721404 uc . H.traverseWithKey (\k v -> p v <?> Key k)
1973− FromJSONKeyText f -> withObject "HashMap" $
1405+ FromJSONKeyText f -> withObject "HashMap k v" $
19741406 fmap (mapKey f) . H.traverseWithKey (\k v -> p v <?> Key k)
1975− FromJSONKeyTextParser f -> withObject "HashMap" $
1407+ FromJSONKeyTextParser f -> withObject "HashMap k v" $
19761408 H.foldrWithKey (\k v m -> H.insert <$> f k <?> Key k <*> p v <?> Key k <*> m) (pure H.empty)
1977− FromJSONKeyValue f -> withArray "Map" $ \arr ->
1978− fmap H.fromList . Tr.sequence .
1979− zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr
1409+ FromJSONKeyValue f -> withArray "Map k v" $ \arr ->
1410+ H.fromList <$> (Tr.sequence .
1411+ zipWith (parseIndexedJSONPair f p) [0..] . V.toList $ arr)
19801412 where
19811413 uc :: Parser (H.HashMap Text v) -> Parser (H.HashMap k v)
19821414 uc = unsafeCoerce
@@ -1997,33 +1429,11 @@ instance FromJSON DotNetTime where
19971429 parseJSON = withText "DotNetTime" $ \t ->
19981430 let (s,m) = T.splitAt (T.length t - 5) t
19991431 t' = T.concat [s,".",m]
2000− in case parseTimeM True defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
1432+ in case parseTime defaultTimeLocale "/Date(%s%Q)/" (unpack t') of
20011433 Just d -> pure (DotNetTime d)
20021434 _ -> fail "could not parse .NET time"
20031435 {-# INLINE parseJSON #-}
20041436
2005−-------------------------------------------------------------------------------
2006−-- primitive
2007−-------------------------------------------------------------------------------
2008−
2009−instance FromJSON a => FromJSON (PM.Array a) where
2010− -- note: we could do better than this if vector exposed the data
2011− -- constructor in Data.Vector.
2012− parseJSON = fmap Exts.fromList . parseJSON
2013−
2014−instance FromJSON a => FromJSON (PM.SmallArray a) where
2015− parseJSON = fmap Exts.fromList . parseJSON
2016−
2017−#if MIN_VERSION_primitive(0,6,4)
2018−instance (PM.Prim a,FromJSON a) => FromJSON (PM.PrimArray a) where
2019− parseJSON = fmap Exts.fromList . parseJSON
2020−
2021−#if !MIN_VERSION_primitive(0,7,0)
2022−instance (PM.PrimUnlifted a,FromJSON a) => FromJSON (PM.UnliftedArray a) where
2023− parseJSON = fmap Exts.fromList . parseJSON
2024−#endif
2025−#endif
2026−
20271437-------------------------------------------------------------------------------
20281438-- time
20291439-------------------------------------------------------------------------------
@@ -2049,17 +1459,6 @@ instance FromJSONKey LocalTime where
20491459 fromJSONKey = FromJSONKeyTextParser (Time.run Time.localTime)
20501460
20511461
2052−-- | Supported string formats:
2053−--
2054−-- @YYYY-MM-DD HH:MM Z@
2055−-- @YYYY-MM-DD HH:MM:SS Z@
2056−-- @YYYY-MM-DD HH:MM:SS.SSS Z@
2057−--
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.
20631462instance FromJSON ZonedTime where
20641463 parseJSON = withText "ZonedTime" (Time.run Time.zonedTime)
20651464
@@ -2074,168 +1473,41 @@ instance FromJSONKey UTCTime where
20741473 fromJSONKey = FromJSONKeyTextParser (Time.run Time.utcTime)
20751474
20761475
2077−-- | This instance includes a bounds check to prevent maliciously
2078−-- large inputs to fill up the memory of the target system. You can
2079−-- newtype 'Scientific' and provide your own instance using
2080−-- 'withScientific' if you want to allow larger inputs.
1476+-- | /WARNING:/ Only parse lengths of time from trusted input
1477+-- since an attacker could easily fill up the memory of the target
1478+-- system by specifying a scientific number with a big exponent like
1479+-- @1e1000000000@.
20811480instance FromJSON NominalDiffTime where
2082− parseJSON = withBoundedScientific "NominalDiffTime" $ pure . realToFrac
1481+ parseJSON = withScientific "NominalDiffTime" $ pure . realToFrac
20831482 {-# INLINE parseJSON #-}
20841483
2085−
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 #-}
2093−
2094−instance FromJSON SystemTime where
2095− parseJSON v = prependContext "SystemTime" $ do
2096− n <- parseJSON v
2097− let n' = floor (n * fromInteger (resolution n) :: Nano)
2098− let (secs, nano) = n' `divMod` resolution n
2099− return (MkSystemTime (fromInteger secs) (fromInteger nano))
2100−
2101−instance FromJSON CalendarDiffTime where
2102− parseJSON = withObject "CalendarDiffTime" $ \obj -> CalendarDiffTime
2103− <$> obj .: "months"
2104− <*> obj .: "time"
2105−
2106−instance FromJSON CalendarDiffDays where
2107− parseJSON = withObject "CalendarDiffDays" $ \obj -> CalendarDiffDays
2108− <$> obj .: "months"
2109− <*> obj .: "days"
2110−
2111−instance FromJSON DayOfWeek where
2112− parseJSON = withText "DaysOfWeek" parseDayOfWeek
2113−
2114−parseDayOfWeek :: T.Text -> Parser DayOfWeek
2115−parseDayOfWeek t = case T.toLower t of
2116− "monday" -> return Monday
2117− "tuesday" -> return Tuesday
2118− "wednesday" -> return Wednesday
2119− "thursday" -> return Thursday
2120− "friday" -> return Friday
2121− "saturday" -> return Saturday
2122− "sunday" -> return Sunday
2123− _ -> fail "Invalid week day"
2124−
2125−instance FromJSONKey DayOfWeek where
2126− fromJSONKey = FromJSONKeyTextParser parseDayOfWeek
2127−
21281484-------------------------------------------------------------------------------
21291485-- base Monoid/Semigroup
21301486-------------------------------------------------------------------------------
21311487
2132−instance FromJSON1 Monoid.Dual where
2133− liftParseJSON p _ = fmap Monoid.Dual . p
2134− {-# INLINE liftParseJSON #-}
2135−
2136−instance FromJSON a => FromJSON (Monoid.Dual a) where
2137− parseJSON = parseJSON1
2138− {-# INLINE parseJSON #-}
2139−
2140−
2141−instance FromJSON1 Monoid.First where
2142− liftParseJSON p p' = fmap Monoid.First . liftParseJSON p p'
1488+instance FromJSON1 Dual where
1489+ liftParseJSON p _ = fmap Dual . p
21431490 {-# INLINE liftParseJSON #-}
21441491
2145−instance FromJSON a => FromJSON (Monoid.First a) where
1492+instance FromJSON a => FromJSON (Dual a) where
21461493 parseJSON = parseJSON1
21471494 {-# INLINE parseJSON #-}
21481495
21491496
2150−instance FromJSON1 Monoid.Last where
2151− liftParseJSON p p' = fmap Monoid.Last . liftParseJSON p p'
1497+instance FromJSON1 First where
1498+ liftParseJSON p p' = fmap First . liftParseJSON p p'
21521499 {-# INLINE liftParseJSON #-}
21531500
2154−instance FromJSON a => FromJSON (Monoid.Last a) where
1501+instance FromJSON a => FromJSON (First a) where
21551502 parseJSON = parseJSON1
21561503 {-# INLINE parseJSON #-}
21571504
21581505
2159−instance FromJSON1 Semigroup.Min where
2160− liftParseJSON p _ a = Semigroup.Min <$> p a
1506+instance FromJSON1 Last where
1507+ liftParseJSON p p' = fmap Last . liftParseJSON p p'
21611508 {-# INLINE liftParseJSON #-}
21621509
2163− liftParseJSONList _ p a = fmap Semigroup.Min <$> p a
2164− {-# INLINE liftParseJSONList #-}
2165−
2166−instance (FromJSON a) => FromJSON (Semigroup.Min a) where
2167− parseJSON = parseJSON1
2168− {-# INLINE parseJSON #-}
2169−
2170− parseJSONList = liftParseJSONList parseJSON parseJSONList
2171− {-# INLINE parseJSONList #-}
2172−
2173−
2174−instance FromJSON1 Semigroup.Max where
2175− liftParseJSON p _ a = Semigroup.Max <$> p a
2176− {-# INLINE liftParseJSON #-}
2177−
2178− liftParseJSONList _ p a = fmap Semigroup.Max <$> p a
2179− {-# INLINE liftParseJSONList #-}
2180−
2181−instance (FromJSON a) => FromJSON (Semigroup.Max a) where
2182− parseJSON = parseJSON1
2183− {-# INLINE parseJSON #-}
2184−
2185− parseJSONList = liftParseJSONList parseJSON parseJSONList
2186− {-# INLINE parseJSONList #-}
2187−
2188−
2189−instance FromJSON1 Semigroup.First where
2190− liftParseJSON p _ a = Semigroup.First <$> p a
2191− {-# INLINE liftParseJSON #-}
2192−
2193− liftParseJSONList _ p a = fmap Semigroup.First <$> p a
2194− {-# INLINE liftParseJSONList #-}
2195−
2196−instance (FromJSON a) => FromJSON (Semigroup.First a) where
2197− parseJSON = parseJSON1
2198− {-# INLINE parseJSON #-}
2199−
2200− parseJSONList = liftParseJSONList parseJSON parseJSONList
2201− {-# INLINE parseJSONList #-}
2202−
2203−
2204−instance FromJSON1 Semigroup.Last where
2205− liftParseJSON p _ a = Semigroup.Last <$> p a
2206− {-# INLINE liftParseJSON #-}
2207−
2208− liftParseJSONList _ p a = fmap Semigroup.Last <$> p a
2209− {-# INLINE liftParseJSONList #-}
2210−
2211−instance (FromJSON a) => FromJSON (Semigroup.Last a) where
2212− parseJSON = parseJSON1
2213− {-# INLINE parseJSON #-}
2214−
2215− parseJSONList = liftParseJSONList parseJSON parseJSONList
2216− {-# INLINE parseJSONList #-}
2217−
2218−
2219−instance FromJSON1 Semigroup.WrappedMonoid where
2220− liftParseJSON p _ a = Semigroup.WrapMonoid <$> p a
2221− {-# INLINE liftParseJSON #-}
2222−
2223− liftParseJSONList _ p a = fmap Semigroup.WrapMonoid <$> p a
2224− {-# INLINE liftParseJSONList #-}
2225−
2226−instance (FromJSON a) => FromJSON (Semigroup.WrappedMonoid a) where
2227− parseJSON = parseJSON1
2228− {-# INLINE parseJSON #-}
2229−
2230− parseJSONList = liftParseJSONList parseJSON parseJSONList
2231− {-# INLINE parseJSONList #-}
2232−
2233−
2234−instance FromJSON1 Semigroup.Option where
2235− liftParseJSON p p' = fmap Semigroup.Option . liftParseJSON p p'
2236− {-# INLINE liftParseJSON #-}
2237−
2238−instance FromJSON a => FromJSON (Semigroup.Option a) where
1510+instance FromJSON a => FromJSON (Last a) where
22391511 parseJSON = parseJSON1
22401512 {-# INLINE parseJSON #-}
22411513
@@ -2243,21 +1515,11 @@ instance FromJSON a => FromJSON (Semigroup.Option a) where
22431515-- tagged
22441516-------------------------------------------------------------------------------
22451517
2246−instance FromJSON1 Proxy where
2247− {-# INLINE liftParseJSON #-}
2248− liftParseJSON _ _ = fromNull "Proxy" Proxy
2249−
22501518instance FromJSON (Proxy a) where
22511519 {-# INLINE parseJSON #-}
2252− parseJSON = fromNull "Proxy" Proxy
1520+ parseJSON Null = pure Proxy
1521+ parseJSON v = typeMismatch "Proxy" v
22531522
2254−fromNull :: String -> a -> Value -> Parser a
2255−fromNull _ a Null = pure a
2256−fromNull c _ v = prependContext c (typeMismatch "Null" v)
2257−
2258−instance FromJSON2 Tagged where
2259− liftParseJSON2 _ _ p _ = fmap Tagged . p
2260− {-# INLINE liftParseJSON2 #-}
22611523
22621524instance FromJSON1 (Tagged a) where
22631525 liftParseJSON p _ = fmap Tagged . p
@@ -2280,7 +1542,10 @@ instance (FromJSON a, FromJSON b, FromJSON c) => FromJSONKey (a,b,c)
22801542instance (FromJSON a, FromJSON b, FromJSON c, FromJSON d) => FromJSONKey (a,b,c,d)
22811543
22821544instance FromJSONKey Char where
2283− fromJSONKey = FromJSONKeyTextParser parseChar
1545+ fromJSONKey = FromJSONKeyTextParser $ \t ->
1546+ if T.length t == 1
1547+ then return (T.index t 0)
1548+ else typeMismatch "Expected Char but String didn't contain exactly one character" (String t)
22841549 fromJSONKeyList = FromJSONKeyText T.unpack
22851550
22861551instance (FromJSONKey a, FromJSON a) => FromJSONKey [a] where
@@ -2290,7 +1555,7 @@ instance (FromJSONKey a, FromJSON a) => FromJSONKey [a] where
22901555-- Tuple instances, see tuple-instances-from.hs
22911556-------------------------------------------------------------------------------
22921557
2293−instance FromJSON2 (,) where
1558+instance FromJSON2 ((,) ) where
22941559 liftParseJSON2 pA _ pB _ = withArray "(a, b)" $ \t ->
22951560 let n = V.length t
22961561 in if n == 2