fastjson VS go-codec

I’ve used fastjson when unmarshalling to Structs is inconvenient. https://github.com/valyala/fastjson

Interesting approach, even though reflection support is supposed to be landing soon, this would be really really useful when using TinyGo. (Fro example, writing web backend serverless functions with Fermyon’s Spin framework for WASM that needs to return JSON). Do you have any benchmarks on how it performs vs stdlib’s encoding/json and/or something like fastjson?

It relies heavily on bytes.IndexOf for which Go provides SIMD optimizations transparently. However, it has some correctness issues when parsing malformed json that might need to be addressed. Generally it is recommended to be used with trusted json documents for internal services and may require further testing before being used to parse arbitrary json documents.

Try fastjson library. It allows you to grab deeply nested json objects without marshalling the entire json.

Como herramientas te recomiendo: FastJson https://github.com/valyala/fastjson : Si necesitas leer jsons Testify https://github.com/stretchr/testify : Para mockear y testear

In Go if I need to extract just a few fields from a large JSON document it's hard to beat https://github.com/valyala/fastjson

Another option is to use what I like to call "Lazy" decoders, like https://github.com/valyala/fastjson which will work with TinyGo, but doesn't have the same type of API as the standard lib (or alternatives) in terms of Marshaling and Unmarshalling. Instead you "Parse" a JSON object, and use Getters to access the types you want.

go-codec depends on reflect