This is a simplified flate compression algorithm based on Go's implementation: https://cs.opensource.google/go/go/+/refs/tags/go1.23.1:src/compress/flate/deflatefast.go which has the copyright notice:

// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

The code has been updated to support compiler:

$ moon version --all
moon 0.1.20241216 (b57ed1c 2024-12-16) ~/.moon/bin/moon
moonc v0.1.20241216+68e710374 ~/.moon/bin/moonc
moonrun 0.1.20241216 (b57ed1c 2024-12-16) ~/.moon/bin/moonrun

Use moonup to manage moon compiler versions: https://github.com/chawyehsu/moonup