hw-json 1.3.1.1 → 1.3.2.0

raw patch · 13 files changed

+207/−106 lines, 13 filesdep +doctestdep +doctest-discoverdep +unordered-containersdep −semigroupsdep ~basedep ~generic-lensdep ~hw-balancedparensPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

Dependencies added: doctest, doctest-discover, unordered-containers

Dependencies removed: semigroups

Dependency ranges changed: base, generic-lens, hw-balancedparens

API changes (from Hackage documentation)

Files

• README.md +24/−48
• app/App/Commands.hs +2/−1
• app/App/Commands/Count.hs +1/−2
• app/App/Commands/CountAeson.hs +52/−0
• app/App/Commands/CreateIndex.hs +0/−1
• app/App/Commands/Demo.hs +0/−1
• app/App/Commands/Types.hs +7/−1
• app/Main.hs +0/−1
• doctest/DoctestDriver.hs +12/−0
• hw-json.cabal +60/−46
• src/HaskellWorks/Data/Json/Internal/Slurp.hs +18/−0
• src/HaskellWorks/Data/Json/LightJson.hs +28/−5
• test/HaskellWorks/Data/Json/Simple/CursorSpec.hs +3/−0

@@ -1,4 +1,5 @@ # hw-json+ [![master](https://circleci.com/gh/haskell-works/hw-json/tree/master.svg?style=svg)](https://circleci.com/gh/haskell-works/hw-json/tree/master)  `hw-json` is a succinct JSON parsing library.@@ -34,12 +35,11 @@ ```haskell -- CMD                                                     -- Mem (MB) ---------------------------------------------------------- -- ---------import Control.DeepSeq                                     --       94-import Data.Aeson                                          --      100-import qualified Data.ByteString.Lazy as BSL               --      104-bs <- BSL.readFile "../corpus/bench/hospitalisation.json"  --      105-let !x = deepseq bs bs                                     --      146-let !y = decode json78m :: Maybe Value                     --      669+import Control.DeepSeq                                     --      345+import Data.Aeson                                          --      371+import qualified Data.ByteString.Lazy as LBS               --      376+!bs <- LBS.readFile "corpus/bench/hospitalisation.json"    --      380+let !y = decode bs :: Maybe Value                          --      928 ```  ### Parsing large Json files in Haskell with hw-json@@ -47,20 +47,12 @@ ```haskell -- CMD                                                                -- Mem (MB) --------------------------------------------------------------------- -- ---------import Foreign                                                        --       93-import Control.Monad                                                  --       95-import Data.Word                                                      --       96-import HaskellWorks.Data.BalancedParens.Simple                        --       97-import HaskellWorks.Data.Bits.BitShown                                --       98-import HaskellWorks.Data.FromForeignRegion                            --       99-import HaskellWorks.Data.Json.Backend.Standard.Cursor                 --      106-import System.IO.MMap                                                 --      109-import qualified Data.ByteString                              as BS   --      110-import qualified Data.Vector.Storable                         as DVS  --      111-import qualified HaskellWorks.Data.ByteString                 as BS   --      112-import qualified HaskellWorks.Data.Json.Backend.Standard.Fast as FAST --      114-bs <- BS.mmap "../corpus/bench/hospitalisation.json"                  --      115-let !cursor = FAST.makeCursor bs                                      --      203+import qualified HaskellWorks.Data.ByteString                as BS    --      351+import qualified HaskellWorks.Data.Json.Standard.Cursor.Fast as JCF   --      353++!jsonBs <- BS.mmap "corpus/bench/hospitalisation.json"                --      355+let !ibip = JCF.simdToIbBp jsonBs                                     --      358+let !c    = JCF.fromBsIbBp jsonBs ibip                                --      495 ```  ## Examples@@ -69,32 +61,18 @@  ```haskell import Control.Monad-import Data.String-import Data.Word-import HaskellWorks.Data.BalancedParens.Simple-import HaskellWorks.Data.Bits.BitShow-import HaskellWorks.Data.Bits.BitShown-import HaskellWorks.Data.FromForeignRegion-import HaskellWorks.Data.Json.Backend.Standard.Cursor-import HaskellWorks.Data.Json.Internal.Token.Types-import HaskellWorks.Data.RankSelect.Base.Rank0-import HaskellWorks.Data.RankSelect.Base.Rank1-import HaskellWorks.Data.RankSelect.Base.Select1-import HaskellWorks.Data.RankSelect.CsPoppy-import System.IO.MMap -import qualified Data.ByteString                                as BS-import qualified Data.Vector.Storable                           as DVS-import qualified HaskellWorks.Data.Json.Backend.Standard.Cursor as C-import qualified HaskellWorks.Data.Json.Backend.Standard.Fast   as FAST-import qualified HaskellWorks.Data.TreeCursor                   as TC+import qualified Data.ByteString                             as BS+import qualified HaskellWorks.Data.Json.Standard.Cursor.Fast as JCF+import qualified HaskellWorks.Data.TreeCursor                as TC  let fc = TC.firstChild let ns = TC.nextSibling let pn = TC.parent let ss = TC.subtreeSize-let cursor = FAST.makeCursor "[null, {\"field\": 1}]"-cursor+let jsonBs  = "[null, {\"field\": 1}]" :: BS.ByteString+let ibip    = JCF.simdToIbBp jsonBs+let cursor  = JCF.fromBsIbBp jsonBs ibip fc cursor (fc >=> ns) cursor ```@@ -105,20 +83,18 @@ import Control.Monad import Data.Function import Data.List-import HaskellWorks.Data.Json.Backend.Standard.Load.Cursor-import HaskellWorks.Data.Json.Backend.Standard.Load.Partial-import HaskellWorks.Data.Json.Backend.Standard.Load.Raw import HaskellWorks.Data.Json.PartialValue+import HaskellWorks.Data.Json.Standard.Cursor.Load.Cursor+import HaskellWorks.Data.Json.Standard.Load.Partial import HaskellWorks.Data.MQuery import HaskellWorks.Data.MQuery.Micro-import HaskellWorks.Data.MQuery.Row  import qualified Data.DList as DL -!cursor <- loadPartial "../corpus/bench/78mb.json"-!cursor <- loadCursorWithIndex "../corpus/bench/78mb.json"-!cursor <- loadCursor "../corpus/bench/78mb.json"-!cursor <- loadCursorWithCsPoppyIndex "../corpus/bench/78mb.json"+!cursor <- loadPartial "corpus/bench/78mb.json"+!cursor <- loadCursorWithIndex "corpus/bench/78mb.json"+!cursor <- loadCursor "corpus/bench/78mb.json"+!cursor <- loadCursorWithCsPoppyIndex "corpus/bench/78mb.json" let !json = jsonPartialJsonValueAt cursor let q = MQuery (DL.singleton json) 

@@ -1,9 +1,9 @@ module App.Commands where  import App.Commands.Count+import App.Commands.CountAeson import App.Commands.CreateIndex import App.Commands.Demo-import Data.Semigroup           ((<>)) import Options.Applicative  commands :: Parser (IO ())@@ -14,4 +14,5 @@   <>  commandGroup "Commands:"   <>  cmdCreateIndex   <>  cmdCount+  <>  cmdCountAeson   <>  cmdDemo

@@ -11,7 +11,6 @@ import Control.Lens import Control.Monad import Data.Generics.Product.Any-import Data.Semigroup                                 ((<>)) import Data.Word import HaskellWorks.Data.FromForeignRegion import HaskellWorks.Data.Json.LightJson@@ -88,7 +87,7 @@         <>  metavar "FILE"         )   <*> optional optsFileIndex-  <*> option auto+  <*> strOption         (   long "expression"         <>  help "JSON expression"         <>  metavar "EXPRESSION"

@@ -0,0 +1,52 @@+{-# LANGUAGE DataKinds           #-}+{-# LANGUAGE OverloadedStrings   #-}+{-# LANGUAGE ScopedTypeVariables #-}+{-# LANGUAGE TypeApplications    #-}++module App.Commands.CountAeson+  ( cmdCountAeson+  ) where++import Control.Lens+import Data.Generics.Product.Any+import Options.Applicative       hiding (columns)++import qualified App.Commands.Types   as Z+import qualified Data.Aeson           as J+import qualified Data.ByteString.Lazy as LBS+import qualified Data.HashMap.Strict  as SHM+import qualified System.IO            as IO++runCountAeson :: Z.CountAesonOptions -> IO ()+runCountAeson opts = do+  let inputFile   = opts ^. the @"inputFile"+  let expression  = opts ^. the @"expression"++  lbs <- LBS.readFile inputFile++  let lbsLines = LBS.split 10 lbs++  let count :: Int = sum $ flip fmap lbsLines $ \lbsLine -> case J.decode lbsLine of+        Just (J.Object v) -> if SHM.member expression v then 1 else 0+        _                 -> 0++  IO.putStrLn $ "Count: " <> show count++  return ()++optsCountAeson :: Parser Z.CountAesonOptions+optsCountAeson = Z.CountAesonOptions+  <$> strOption+        (   long "input"+        <>  short 'i'+        <>  help "Input JSON file"+        <>  metavar "FILE"+        )+  <*> strOption+        (   long "expression"+        <>  help "JSON expression"+        <>  metavar "EXPRESSION"+        )++cmdCountAeson :: Mod CommandFields (IO ())+cmdCountAeson = command "count-aeson"  $ flip info idm $ runCountAeson <$> optsCountAeson

@@ -11,7 +11,6 @@ import Control.Monad import Data.Generics.Product.Any import Data.Maybe-import Data.Semigroup            ((<>)) import Data.Word import Foreign import Options.Applicative       hiding (columns)

@@ -11,7 +11,6 @@ import Control.Lens import Control.Monad import Data.Generics.Product.Any-import Data.Semigroup                                     ((<>)) import Data.Word import Foreign.ForeignPtr import HaskellWorks.Data.Json.LightJson

@@ -2,7 +2,8 @@ {-# LANGUAGE DuplicateRecordFields #-}  module App.Commands.Types-  ( CountOptions(..)+  ( CountAesonOptions(..)+  , CountOptions(..)   , CreateIndexOptions(..)   , DemoOptions(..)   , FileIndexes(..)@@ -27,6 +28,11 @@ data CountOptions = CountOptions   { inputFile  :: FilePath   , indexes    :: Maybe FileIndexes+  , expression :: Text+  } deriving (Eq, Show, Generic)++data CountAesonOptions = CountAesonOptions+  { inputFile  :: FilePath   , expression :: Text   } deriving (Eq, Show, Generic) 

@@ -2,7 +2,6 @@  import App.Commands import Control.Monad-import Data.Semigroup      ((<>)) import Options.Applicative  main :: IO ()

@@ -0,0 +1,12 @@+{-# LANGUAGE CPP #-}++#if MIN_VERSION_GLASGOW_HASKELL(8,4,4,0)+{-# OPTIONS_GHC -F -pgmF doctest-discover #-}+#else+module Main where++import qualified System.IO as IO++main :: IO ()+main = IO.putStrLn "WARNING: doctest will not run on GHC versions earlier than 8.4.4"+#endif

@@ -1,7 +1,7 @@ cabal-version:  2.2  name:                   hw-json-version:                1.3.1.1+version:                1.3.2.0 synopsis:               Memory efficient JSON parser description:            Memory efficient JSON parser. Please see README.md category:               Data@@ -9,10 +9,10 @@ bug-reports:            https://github.com/haskell-works/hw-json/issues author:                 John Ky maintainer:             newhoggy@gmail.com-copyright:              2016-2019 John Ky+copyright:              2016-2020 John Ky license:                BSD-3-Clause license-file:           LICENSE-tested-with:            GHC == 8.8.1, GHC == 8.6.5, GHC == 8.4.4, GHC == 8.2.2+tested-with:            GHC == 8.10.1, GHC == 8.8.3, GHC == 8.6.5, GHC == 8.4.4 build-type:             Simple extra-source-files:     README.md                         corpus/5000B.json@@ -37,42 +37,43 @@   manual:       False   default:      False -common base                     { build-depends: base                     >= 4          && < 5      }--common aeson                    { build-depends: aeson                    >= 1.4.3.0    && < 1.5    }-common ansi-wl-pprint           { build-depends: ansi-wl-pprint           >= 0.6.8.2    && < 0.7    }-common array                    { build-depends: array                    >= 0.5        && < 0.6    }-common attoparsec               { build-depends: attoparsec               >= 0.13       && < 0.14   }-common bits-extra               { build-depends: bits-extra               >= 0.0.1.3    && < 0.1    }-common bytestring               { build-depends: bytestring               >= 0.10.6     && < 0.11   }-common criterion                { build-depends: criterion                >= 1.4        && < 1.6    }-common directory                { build-depends: directory                >= 1.3        && < 1.4    }-common dlist                    { build-depends: dlist                    >= 0.8        && < 0.9    }-common generic-lens             { build-depends: generic-lens             >= 1.2.0.1    && < 1.3    }-common hedgehog                 { build-depends: hedgehog                 >= 0.6        && < 1.1    }-common hspec                    { build-depends: hspec                    >= 2.4        && < 3      }-common hw-balancedparens        { build-depends: hw-balancedparens        >= 0.3.0.0    && < 0.4    }-common hw-bits                  { build-depends: hw-bits                  >= 0.7.0.5    && < 0.8    }-common hw-hspec-hedgehog        { build-depends: hw-hspec-hedgehog        >= 0.1.0.4    && < 0.2    }-common hw-json-simd             { build-depends: hw-json-simd             >= 0.1.0.2    && < 0.2    }-common hw-json-simple-cursor    { build-depends: hw-json-simple-cursor    >= 0.1.0.1    && < 0.2    }-common hw-json-standard-cursor  { build-depends: hw-json-standard-cursor  >= 0.2.0.1    && < 0.3    }-common hw-mquery                { build-depends: hw-mquery                >= 0.2.0.0    && < 0.3    }-common hw-parser                { build-depends: hw-parser                >= 0.1        && < 0.2    }-common hw-prim                  { build-depends: hw-prim                  >= 0.6.2.32   && < 0.7    }-common hw-rankselect            { build-depends: hw-rankselect            >= 0.13       && < 0.14   }-common hw-rankselect-base       { build-depends: hw-rankselect-base       >= 0.3.2.1    && < 0.4    }-common hw-simd                  { build-depends: hw-simd                  >= 0.1.1.2    && < 0.2    }-common lens                     { build-depends: lens                     >= 4          && < 5      }-common mmap                     { build-depends: mmap                     >= 0.5        && < 0.6    }-common optparse-applicative     { build-depends: optparse-applicative     >= 0.14       && < 0.16   }-common scientific               { build-depends: scientific               >= 0.3.6.2    && < 0.4    }-common text                     { build-depends: text                     >= 1.2        && < 1.3    }-common transformers             { build-depends: transformers             >= 0.4        && < 0.6    }-common vector                   { build-depends: vector                   >= 0.12       && < 0.13   }-common word8                    { build-depends: word8                    >= 0.1        && < 0.2    }+common base                       { build-depends: base                       >= 4.11       && < 5      } -common semigroups   { if impl(ghc <  8    ) { build-depends: semigroups     >= 0.16     && < 0.19 } }+common aeson                      { build-depends: aeson                      >= 1.4.3.0    && < 1.5    }+common ansi-wl-pprint             { build-depends: ansi-wl-pprint             >= 0.6.8.2    && < 0.7    }+common array                      { build-depends: array                      >= 0.5        && < 0.6    }+common attoparsec                 { build-depends: attoparsec                 >= 0.13       && < 0.14   }+common bits-extra                 { build-depends: bits-extra                 >= 0.0.1.3    && < 0.1    }+common bytestring                 { build-depends: bytestring                 >= 0.10.6     && < 0.11   }+common criterion                  { build-depends: criterion                  >= 1.4        && < 1.6    }+common directory                  { build-depends: directory                  >= 1.3        && < 1.4    }+common dlist                      { build-depends: dlist                      >= 0.8        && < 0.9    }+common doctest                    { build-depends: doctest                    >= 0.16.2     && < 0.17   }+common doctest-discover           { build-depends: doctest-discover           >= 0.2        && < 0.3    }+common generic-lens               { build-depends: generic-lens               >= 1.2.0.1    && < 1.3    }+common hedgehog                   { build-depends: hedgehog                   >= 0.6        && < 1.1    }+common hspec                      { build-depends: hspec                      >= 2.4        && < 3      }+common hw-balancedparens          { build-depends: hw-balancedparens          >= 0.3.0.0    && < 0.4    }+common hw-bits                    { build-depends: hw-bits                    >= 0.7.0.5    && < 0.8    }+common hw-hspec-hedgehog          { build-depends: hw-hspec-hedgehog          >= 0.1.0.4    && < 0.2    }+common hw-json-simd               { build-depends: hw-json-simd               >= 0.1.0.2    && < 0.2    }+common hw-json-simple-cursor      { build-depends: hw-json-simple-cursor      >= 0.1.0.1    && < 0.2    }+common hw-json-standard-cursor    { build-depends: hw-json-standard-cursor    >= 0.2.0.1    && < 0.3    }+common hw-mquery                  { build-depends: hw-mquery                  >= 0.2.0.0    && < 0.3    }+common hw-parser                  { build-depends: hw-parser                  >= 0.1        && < 0.2    }+common hw-prim                    { build-depends: hw-prim                    >= 0.6.2.32   && < 0.7    }+common hw-rankselect              { build-depends: hw-rankselect              >= 0.13       && < 0.14   }+common hw-rankselect-base         { build-depends: hw-rankselect-base         >= 0.3.2.1    && < 0.4    }+common hw-simd                    { build-depends: hw-simd                    >= 0.1.1.2    && < 0.2    }+common lens                       { build-depends: lens                       >= 4          && < 5      }+common mmap                       { build-depends: mmap                       >= 0.5        && < 0.6    }+common optparse-applicative       { build-depends: optparse-applicative       >= 0.14       && < 0.16   }+common scientific                 { build-depends: scientific                 >= 0.3.6.2    && < 0.4    }+common text                       { build-depends: text                       >= 1.2        && < 1.3    }+common transformers               { build-depends: transformers               >= 0.4        && < 0.6    }+common unordered-containers       { build-depends: unordered-containers       >= 0.2        && < 0.3    }+common vector                     { build-depends: vector                     >= 0.12       && < 0.13   }+common word8                      { build-depends: word8                      >= 0.1        && < 0.2    }  common config   default-language:     Haskell2010@@ -83,6 +84,9 @@     ghc-options:        -mbmi2 -msse4.2     cpp-options:        -DBMI2_ENABLED +common hw-json+  build-depends:        hw-json+ library   import:               base, config                       , aeson@@ -102,7 +106,6 @@                       , hw-rankselect-base                       , hw-simd                       , mmap-                      , semigroups                       , text                       , vector                       , word8@@ -132,10 +135,12 @@  executable hw-json   import:               base, config+                      , aeson                       , bytestring                       , dlist                       , generic-lens                       , hw-balancedparens+                      , hw-json                       , hw-json-simd                       , hw-json-simple-cursor                       , hw-json-standard-cursor@@ -146,16 +151,16 @@                       , lens                       , mmap                       , optparse-applicative-                      , semigroups                       , text+                      , unordered-containers                       , vector   main-is:              Main.hs   hs-source-dirs:       app   ghc-options:          -threaded -rtsopts -with-rtsopts=-N-  build-depends:        hw-json   other-modules:        App.Commands                         App.Commands.CreateIndex                         App.Commands.Count+                        App.Commands.CountAeson                         App.Commands.Demo                         App.Commands.Types @@ -169,6 +174,7 @@                       , hw-balancedparens                       , hw-bits                       , hw-hspec-hedgehog+                      , hw-json                       , hw-json-simple-cursor                       , hw-json-standard-cursor                       , hw-prim@@ -180,7 +186,6 @@                       , vector   type:                 exitcode-stdio-1.0   main-is:              Spec.hs-  build-depends:        hw-json   hs-source-dirs:       test   ghc-options:          -threaded -rtsopts -with-rtsopts=-N   build-tool-depends:   hspec-discover:hspec-discover@@ -191,18 +196,27 @@                         HaskellWorks.Data.Json.Token.TokenizeSpec                         HaskellWorks.Data.Json.TypeSpec                         HaskellWorks.Data.Json.ValueSpec-                        Paths_hw_json  benchmark bench   import:               base, config                       , bytestring                       , criterion                       , directory+                      , hw-json                       , hw-json-standard-cursor                       , mmap-                      , semigroups   type:                 exitcode-stdio-1.0   main-is:              Main.hs   hs-source-dirs:       bench-  build-depends:        hw-json-  other-modules:        Paths_hw_json++test-suite hw-json-doctest+  import:               base, config+                      , doctest+                      , doctest-discover+                      , hw-json+  default-language:     Haskell2010+  type:                 exitcode-stdio-1.0+  ghc-options:          -threaded+  main-is:              DoctestDriver.hs+  HS-Source-Dirs:       doctest+  build-tool-depends:   doctest-discover:doctest-discover

@@ -24,11 +24,29 @@   | InNumber   | InIdent +-- | Slurp a JSON string+--+-- Examples:+--+-- >>> :set -XOverloadedStrings+-- >>> slurpText "\"Hello\""+-- Right "Hello"+-- >>> slurpText "123"+-- Left "34: Failed reading: satisfy" slurpText :: BS.ByteString -> Either Text Text slurpText bs = case PBS.parseOnly AP.jstring bs of   Right t -> Right t   Left e  -> Left (T.pack e) +-- | Slurp a JSON number+--+-- Examples:+--+-- >>> :set -XOverloadedStrings+-- >>> slurpNumber "123, true"+-- "123"+-- >>> slurpNumber "\"Hello\""+-- "\"Hello\"" slurpNumber :: BS.ByteString -> BS.ByteString slurpNumber bs = let (!cs, _) = BS.unfoldrN (BS.length bs) genNumber (InJson, bs) in cs     where genNumber :: (JsonState, BS.ByteString) -> Maybe (Word8, (JsonState, BS.ByteString))

@@ -33,10 +33,12 @@ import Prelude                                        hiding (drop) import Text.PrettyPrint.ANSI.Leijen -import qualified Data.ByteString                  as BS-import qualified Data.List                        as L-import qualified Data.Text                        as T-import qualified HaskellWorks.Data.BalancedParens as BP+import qualified Data.ByteString                      as BS+import qualified Data.ByteString.Unsafe               as BSU+import qualified Data.List                            as L+import qualified Data.Text                            as T+import qualified HaskellWorks.Data.BalancedParens     as BP+import qualified HaskellWorks.Data.Json.Simple.Cursor as JSC  data LightJson c   = LightJsonString Text@@ -48,11 +50,14 @@   | LightJsonError Text   deriving Show -instance Eq (LightJson c) where+instance LightJsonAt c => Eq (LightJson c) where   (==) (LightJsonString a) (LightJsonString b) = a == b   (==) (LightJsonNumber a) (LightJsonNumber b) = a == b   (==) (LightJsonBool   a) (LightJsonBool   b) = a == b+  (==) (LightJsonObject a) (LightJsonObject b) = fmap (fmap lightJsonAt) a == fmap (fmap lightJsonAt) b+  (==) (LightJsonArray  a) (LightJsonArray  b) = fmap lightJsonAt a == fmap lightJsonAt b   (==)  LightJsonNull       LightJsonNull      = True+  (==) (LightJsonError  a) (LightJsonError  b) = a == b   (==)  _                   _                  = False  data LightJsonField c = LightJsonField Text (LightJson c)@@ -144,3 +149,21 @@           asField (a, b)    = case lightJsonAt a of                                 LightJsonString s -> [(s, b)]                                 _                 -> []++instance (BP.BalancedParens w, Rank0 w, Rank1 w, Select1 v, TestBit w) => LightJsonAt (JSC.JsonCursor BS.ByteString v w) where+  lightJsonAt k = if kra `mod` 2 == 1+    then let i = fromIntegral (kpa - 1) :: Int in+      if i < BS.length kt+        then case BSU.unsafeIndex kt i of+          91  -> LightJsonArray  []+          123 -> LightJsonObject []+          _   -> LightJsonError "Invalid collection character"+        else LightJsonError "Index out of bounds"+    else LightJsonError "Unaligned cursor"+    where kpa   = select1 kib kta + km+          kib   = JSC.interests k+          kra   = JSC.cursorRank k+          ksa   = kra + 1+          kta   = ksa `div` 2+          km    = ksa `mod` 2+          kt    = JSC.cursorText k

@@ -14,6 +14,7 @@   ) where  import Control.Monad+import HaskellWorks.Data.Json.LightJson import HaskellWorks.Hspec.Hedgehog import Hedgehog import Test.Hspec@@ -82,3 +83,5 @@         (V.snippet <$> (fc >=> fc >=> fc              ) k) === Just "11"         (V.snippet <$> (fc >=> fc >=> fc >=> ns       ) k) === Nothing         (V.snippet <$> (fc >=> fc >=> fc >=> fc       ) k) === Nothing+      it "can lightJsonAt" $ requireTest $ do+        lightJsonAt k === LightJsonArray []