mizchi/zlib

Pure MoonBit zlib/deflate implementation.

Features

• zlib streams (compress stored / full inflate)
• raw deflate (stored compress / full inflate)
• gzip (stored compress / full inflate)

Quick Commands

just           # check + test
just fmt       # format code
just check     # type check
just test      # run tests
just bench     # run benchmarks
just bench-compare  # compare vs system zlib (hyperfine)
just test-update  # update snapshot tests
just info      # generate type definition files

Native target

mizchi/zlib itself is pure MoonBit on every target, including native.

If you want the system zlib backend explicitly, import mizchi/zlib/native:

import "mizchi/zlib/native" as @zlib_native

let compressed = @zlib_native.zlib_compress(data)
let decompressed = @zlib_native.zlib_decompress(compressed)

mizchi/zlib/native links -lz internally, so dependents do not need to add native linker flags themselves.

Benchmark (Rust flate2 / miniz_oxide baseline)

Measured on 2026-01-28 with hyperfine --warmup 3 and the bundled 256KiB fixtures. Commands are very short (<5ms), so shell overhead can skew results. wasm/wasm-gc uses moon run, so the runtime/launcher overhead is included.

Format	MoonBit native (mean)	Rust baseline (mean)	Relative	MoonBit wasm (mean)	MoonBit wasm-gc (mean)
zlib	3.8 ms	2.1 ms (flate2/miniz_oxide)	1.8x slower	31.8 ms	22.9 ms
deflate	3.7 ms	2.1 ms (flate2/miniz_oxide)	1.8x slower	30.0 ms	22.6 ms
gzip	4.2 ms	2.2 ms (flate2/miniz_oxide)	1.9x slower	30.7 ms	27.1 ms

Project Structure

zlib/
├── moon.mod
├── src/
│   ├── moon.pkg
│   ├── zlib.mbt
│   ├── inflate.mbt
│   ├── huffman.mbt
│   ├── adler32.mbt
│   └── zlib_test.mbt
└── justfile

License

Apache-2.0