clj-jq

A library to execute jq scripts on JSON data. It is a thin wrapper around jackson-jq.

Available jq functions can be found here.

Alternatives

There is another jq library for Clojure: clj-jq. This library works by shelling-out to an embedded jq. The problem is that it has costs for every invocation. Also, it creates difficulties to use this library with the GraalVM native-image.

Use cases

The library intends to be used for stream processing.

Compiling a script to execute it multiple times

(require '[jq.core :as jq])

(let [data "[1,2,3]"
      query "map(.+1)"
      processor-fn (jq/processor query)]
  (processor-fn data))
=> "[2,3,4]"

Or inline:

((jq/processor "map(.+1)") "[1,2,3]")
=> "[2,3,4]"

One of script execution

(let [data "[1,2,3]"
      query "map(.+1)"]
  (jq/execute data query))
=> "[2,3,4]"

Performance

(use 'criterium.core)
(let [jq-script (time (jq.core/processor ".a[] |= sqrt"))] 
  (quick-bench (jq-script "{\"a\":[10,2,3,4,5],\"b\":\"hello\"}")))
=>
"Elapsed time: 0.098731 msecs"
Evaluation count : 203586 in 6 samples of 33931 calls.
Execution time mean : 3.729388 µs
Execution time std-deviation : 490.874949 ns
Execution time lower quantile : 2.960691 µs ( 2.5%)
Execution time upper quantile : 4.082989 µs (97.5%)
Overhead used : 1.977144 ns

Future work

• [ ] Expose interface to provide custom function

License

Copyright © 2021 Dainius Jocas.

Distributed under The Apache License, Version 2.0.