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go-ruby-ipaddr documentation

Ruby's IPAddr in pure Go — parsing, masking, predicates & operators, MRI byte-exact, no cgo.

go-ruby-ipaddr/ipaddr is a faithful, pure-Go (zero cgo) reimplementation of Ruby's IPAddr, matching reference Ruby (MRI). The module path is github.com/go-ruby-ipaddr/ipaddr.

It is the backend bound into go-embedded-ruby by rbgo as a native module — just like go-ruby-regexp and go-ruby-erb. The dependency runs the other way: this library has no dependency on the Ruby runtime.

Status: complete

Complete — MRI byte-exact. Faithful port of Ruby's IPAddr: parsing (prefixlen / netmask / bracketed IPv6 / %zone / embedded IPv4), formatting (to_s / to_string / cidr / inspect), masking, membership (include? / to_range), the bitwise / arithmetic operators, comparison, the predicates and conversions, all in math/big.Int. Validated by a differential oracle against the system ruby -ripaddr — at 100% coverage, gofmt + go vet clean, CI green across the six 64-bit Go targets and three OSes.

Quick taste

net, _ := ipaddr.New("192.168.1.5/24")
net.ToS()   // "192.168.1.0"   (masked, like MRI)
net.Cidr()  // "192.168.1.0/24"

in, _ := net.Include("192.168.1.99") // true

lo, hi, _ := net.ToRange()           // 192.168.1.0 .. 192.168.1.255

Repositories

Repo What it is
ipaddr the library — Ruby's IPAddr in pure Go
docs this documentation site (MkDocs Material, versioned with mike)
go-ruby-ipaddr.github.io the organization landing page (Hugo)
brand logo and brand assets

Principles

  • Pure Go, CGO_ENABLED=0 — trivial cross-compilation, a single static binary, no C toolchain.
  • MRI byte-exact. Output matches reference Ruby, validated by a differential oracle against the ruby binary.
  • Standalone & reusable. A standalone module bound by rbgo; no dependency on the Ruby runtime — the dependency runs the other way.
  • 100% test coverage is the target, enforced as a CI gate, across 6 arches and 3 OSes.

Where to go next

  • Why pure Go — why this slice of Ruby is deterministic enough to live as a standalone, interpreter-independent Go library.
  • Usage & API — the public surface and worked examples.
  • Roadmap — what is done and what is downstream by design.

Source lives at github.com/go-ruby-ipaddr/ipaddr.