Roadmap

go-ruby-json/json is grown test-first, each capability differential-tested against MRI rather than built in isolation. Ruby's JSON — the deterministic, interpreter-independent slice extracted from rbgo's internals — is complete.

Stage	What	Status
Parser	JSON.parse(s) parses JSON text into the Ruby value graph (Hash/Array/String/Integer/Float/true/false/nil), with symbolize_names to key hashes by Symbol, exactly as MRI's parser does.	Done
Generator	JSON.generate(v) emits compact JSON and JSON.pretty_generate(v) the indented form, matching reference Ruby's spacing and escaping byte-for-byte.	Done
Nesting & limits	Depth tracking that raises JSON::NestingError past the configured limit, mirroring MRI's recursion guard on both parse and generate.	Done
Error taxonomy	The JSON::ParserError / JSON::NestingError / JSON::GeneratorError hierarchy, raised on the same inputs and with the same messages as reference Ruby.	Done
Number & string fidelity	Integers, floats, and escapes (including \uXXXX surrogate pairs) parsed and emitted exactly as MRI, including the float formatting edge cases.	Done
Differential oracle & coverage	A wide corpus round-tripped here and by the system ruby/json, compared byte-for-byte; 100% coverage, gofmt + go vet clean, green across all six 64-bit Go arches and three OSes.	Done

Documented out-of-scope boundaries

These are deliberate, recorded so the module's surface is unambiguous:

• No interpreter. The library implements the deterministic algorithm; it never runs arbitrary Ruby. Anything that needs a live binding or evaluation is the consumer's job — that is why rbgo binds this module rather than the reverse.
• Reference is reference Ruby (MRI). Byte-for-byte conformance targets MRI's behaviour; differences across MRI releases are matched to the reference used by the differential oracle.
• Standalone & reusable. The module has no dependency on the Ruby runtime; the dependency runs the other way.

See Usage & API for the surface and Why pure Go for the deterministic/interpreter split.