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Roadmap

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

Stage What Status
Numeric tower A Num union of Integer (*big.Int), Rational (*big.Rat) and Float (float64), so each part of the Complex is preserved exactly as MRI keeps it on the numeric tower. Done
Exact-preserving arithmetic Add / Sub / Mul / Div / Pow / Neg keep Integer and Rational parts exact; integer powers stay exact, non-integer / Float exponents use the floating polar form. Done
Magnitude & phase Abs, the exact Abs2, Arg / Angle / Phase, Conjugate, Rectangular, PolarParts — Hypot and Atan2 matching MRI. Done
Constructors & parsing New / Rect, Polar, and Parse for the full Complex(string) grammar including polar @, the j unit and _ digit separators. Done
Conversions & rendering ToF / ToI / ToR / ToC, Numerator / Denominator, and MRI-exact Inspect / ToS. Done
Differential oracle & coverage A wide corpus dumped through this library and the system ruby / Complex, 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 numeric algorithm; it never runs arbitrary Ruby. Anything that needs a live binding or coercion against other Ruby numerics 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 Complex. The handful of intrinsically-floating results (Polar, polar Parse, non-integer Pow) can differ by a ULP because Go's pure-Go math is not the platform libm MRI links; those cases are verified under a tolerance.
  • 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.