Roadmap

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

Stage	What	Status
Scanner & parser	A YAML 1.1 scanner and parser following Psych's event model — documents, mappings, sequences, scalars in plain / single / double / literal / folded styles, and the directive and document markers.	Done
Dump emitter	Dump(v) emits Psych-compatible YAML: block style by default with flow where Psych uses it, correct scalar quoting, and stable key ordering — matching reference Ruby's output byte-for-byte.	Done
Load & SafeLoad	Load(s) builds the full Ruby value graph; SafeLoad restricts to the safe scalar/collection subset, refusing arbitrary !ruby/object: instantiation exactly as Psych's safe loader does.	Done
Anchors, aliases & Ruby tags	Anchors &a and aliases *a for shared and cyclic structure, plus the !ruby/object:, !ruby/symbol, !ruby/range and related tags round-tripped the way Psych writes and reads them.	Done
Ruby scalar types	Symbol, Time, Range and arbitrary-precision bignum scalars emitted and parsed with Psych's tag and formatting conventions.	Done
Differential oracle & coverage	A wide value corpus dumped and loaded both here and by the system ruby/Psych, 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.