This is a fast Haskell implementation of the Myers text diff algorithm[^1]. It is heavily inspired by the Python version in this post, and should have the same O(min(len(a), len(b))) space complexity. (By contrast, the Diff package advertises O(ab) space complexity.) The implementation uses unboxed mutable vectors for performance.
This repo also can also build a couple other versions for benchmarking comparison, gated behind flags.
-funi_myers will build the version from the uni-util package.