[shadytrees]

On Ed Yang's repo <https://github.com/ezyang/compact>, which I believe features a version of the Data.Compact module that got merged into base, he gives the example of a spellchecker whose max pauses went from (0.0023,0.0582) to (0.0017,0.0462). In the example the faster version stores the set of dictionary words result you also get disk (de-)serialization, which allows you to amortize the initial cost string parsing.

Unfortunately, I doubt that nondeterministic garbage collection will ever mesh well with high-performance gaming and especially ever with real-time problems. For ordinary systems programming, however, I think it's frequently possible for high-resident-memory applications to build a walled garden for their e.g. in-memory caches or large binary assets.