Roadmap

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

Stage	What	Status
Ordered attribute table	The data structure underneath OpenStruct: an ordered, Symbol-keyed table built from New(pairs...), preserving insertion order exactly as MRI's to_h does.	Done
Accessors	Get / Set (the method_missing reader / name= writer targets), Index / SetIndex ([] / []=), and RespondToField (the table half of respond_to_missing?).	Done
Conversions & traversal	ToH (Symbol keys, insertion order), EachPair, Members, and Dig(keys...) routed through a Digger interface.	Done
delete_field & comparison	DeleteField returns the old value and raises NameError when absent; Equal / Eql implement == / eql?.	Done
MRI-exact inspect	Inspect / String render #<OpenStruct …> byte-for-byte through an Inspector interface with a built-in renderer for common shapes.	Done
Differential oracle & coverage	The inspect format, to_h insertion ordering, and delete_field semantics compared against the system ruby 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 dynamic dispatch. OpenStruct's defining feature — turning any method name into a read or write — is dynamic and needs a live Ruby binding. It lives in the host (rbgo), implemented in terms of this table (Get / Set / RespondToField), not here.
• 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.