hw-mquery

Monadic query DSL http://github.com/haskell-works/hw-mquery#readme

This package is not currently in any snapshots. If you're interested in using it, we recommend adding it to Stackage Nightly. Doing so will make builds more reliable, and allow stackage.org to host generated Haddocks.

BSD-3-Clause licensed by John Ky
Maintained by newhoggy@gmail.com

hw-mquery

master

import Control.Monad
import Data.Function
import Data.List
import HaskellWorks.Data.Json.Load
import HaskellWorks.Data.Json.PartialValue
import HaskellWorks.Data.Micro
import HaskellWorks.Data.MQuery
import HaskellWorks.Data.Row
import HaskellWorks.Diagnostics
import Text.PrettyPrint.ANSI.Leijen

import qualified Data.DList as DL
!json <- loadJsonPartial "../data/78mb.json"
!json <- loadJsonWithIndex "../data/78mb.json"
!json <- loadJsonWithPoppy512Index "../data/78mb.json"
!json <- loadJsonWithPoppy512SMinMaxIndex "../data/78mb.json"
let q = MQuery (DL.singleton json)
putPretty $ q >>= item & limit 10
putPretty $ q >>= item & page 10 1
putPretty $ q >>= item >>= hasKV "founded_year" (JsonPartialNumber 2005) & limit 10
putPretty $ q >>= item >>= entry
putPretty $ q >>= item >>= entry >>= named "name" & limit 10
putPretty $ q >>= item >>= entry >>= satisfying (\(k, _) -> k == "name") >>= value & limit 10
putPretty $ q >>= item >>= entry >>= satisfying ((== "name") . fst) >>= value & limit 10
putPretty $ q >>= (item >=> entry >=> key) & limit 10
putPretty $ q >>= item >>= entry >>= key & limit 100 & onList (uniq . sort)
putPretty $ (q >>= item >>= entry & limit 1) >>= field "name" & limit 10
putPretty $ do {j <- q; e <- item j; (k, v) <- entry e; return k}
putPretty $ do {j <- q; e <- item j; (k, v) <- entry e; guard (k == "name"); return v}

Decoding

Line separated base 64 encoded gzipped json

while read in; do echo “$in” | base64 –decode | gunzip; echo “”; done < file.lgz > firehose.json

Profiling with stack traces

mafia build -p
cabal repl --ghc-options='-fexternal-interpreter -prof'
import HaskellWorks.Data.Succinct.BalancedParens
import HaskellWorks.Data.Succinct.RankSelect.Binary.Poppy512
import HaskellWorks.Data.Positioning
import qualified Data.Vector.Storable as DVS
import HaskellWorks.Data.IndexedSeq
(jsonBS, jsonIb, jsonBp) <- loadJsonRawWithIndex "firehose.json"
let bp1 = SimpleBalancedParens jsonBp
let bp2 = SimpleBalancedParens (makePoppy512 jsonBp)
let bp3 = makePoppy512 jsonBp