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go-ruby-zlib documentation

Ruby's Zlib in pure Go — deflate, gzip, byte-exact CRC-32/Adler-32, no cgo.

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

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 — checksums byte-exact, compressors MRI-interoperable. Faithful port of Ruby's Zlib: Deflate / Inflate, gzip round-trip, the byte-exact CRC-32 / Adler-32 checksums and their combine forms, and a streaming Deflater / Inflater. Validated by a differential oracle against the system ruby — checksums byte-for-byte, deflate / gzip / streaming round-tripped through MRI in both directions — at 100% coverage, gofmt + go vet clean, CI green across the six 64-bit Go targets and three OSes.

Quick taste

comp, _ := zlib.Deflate([]byte("hello world"), zlib.BestCompression)
out, _ := zlib.Inflate(comp)
// out == "hello world"

// Byte-exact checksums (seed 0 for CRC, 1 for Adler — the MRI identities).
zlib.Crc32([]byte("hello world"), 0)   // 222957957
zlib.Adler32([]byte("hello world"), 1) // 436929629

Repositories

Repo What it is
zlib the library — Ruby's Zlib in pure Go
docs this documentation site (MkDocs Material, versioned with mike)
go-ruby-zlib.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-zlib/zlib.