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Comment by sgt | Hacker News Reader

On another note, I see Scala is doing really poorly in the JSON benchmark test: https://github.com/kostya/benchmarks#json

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Those aren't very fair to the dynamic languages and JIT compiled languages (this includes Scala).

* For the dynamic languages execution time includes the time it takes to lex, parse and interpret the source code.

* For language implementations with a JIT execution time includes the time the JIT takes to properly optimise hot code paths. Generally you start benchmarking after a warm up period in such cases.

The only fair comparisons are those between ahead of time compiled languages.

The benchmark suited used the STDLIB json parser which is slow as hell. How slow is it? In 2011 there was a proposal to deprecate it, which never happened [1].

Why? STDLIB parser loads the file line-by-line, then copies line by line into a new buffer that joins the strings together. Then the parser is called. The Scala community normally circumvents by using non-standard community developed solutions.

Furthermore JIT vs Compiled language benchmarks are pretty unfair to JIT'd languages. Especially for the JVM which doesn't start to compile sections until >10,000 calls.

[1] https://groups.google.com/forum/m/#!msg/scala-user/P7-8PEUUj...

Well that makes the result pretty much irrelevant as nobody actually uses that lib for any serious JSON parsing.

So which is the go to library for serious parsing in Scala? And how would you change the benchmark to make it fair ?

I'd use Jackson.

No one uses the built-in Scala JSON parser. Checkout jawn[0] or spray-json[1].

[0] https://github.com/non/jawn [1] https://github.com/spray/spray-json

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