That looks great, especially some of the unique optimisations. I gave it a nonscientific test run with a set of 1k different 2-4kb JSON encoded messages that we saw in our day to day traffic using the default Go benchmark library. Compared to easyjson (generated parser) goccy/go-json is unfortunately 20-25% slower and allocated four times the number of bytes.
Any chance that you will implement code generation like easyjson?
Any chance that you will implement code generation like easyjson?