New JSON parser for Go: up to 9x faster than `encoding/json`

go-codec is nice, but in my testing I found it to be slower than Go's encoding/json.

Thanks will add it to the tests

This is very useful, thanks! Go's slow JSON parser is annoying.

My only criticism is that returning 4 values from a function is not very ergonomic, especially since most of the return values aren't needed in many cases.

It would have been better and more idiomatic to return a struct. Alternatively, let it take a pointer to a struct — this would let you avoid memory allocation in loops (though in theory Go should be able to optimize a struct return, too; anyone know?).

Anyone knows good JSON specs to run against?

It's definitely not compliant. I just read the code, there's no support for escapes in strings, except for skipping over escaped double quotes to find the string end. This applies to any string, so it also won't correctly match keys that contain escapes. (hence the small number of allocations)

Edited to add: this has its uses, if you know that's all you need. Long ago I wrote a similar xml parser for a project because we had control over the xml being produced, and the garbage overhead from element names was killing us with Xerces; I didn't bother implementing things like DTD support, because YAGNI.

There is lot of tasks when you need only to read data, 3-rd party API, log processing and lot more. For sure this lib not for everyone, but if you care about performance, and especially memory consumption, this could make sense.

Can you a bit clarify about your expectations?