unicode-collation VS unicode-transforms

https://github.com/jgm/unicode-collation uses IntMap quite a bit and has benchmarks.

Why don't you open an issue at https://github.com/jgm/unicode-collation -- it would be a better place to hash out the details than here.

There are several native Haskell libraries, covering individual features of text-icu: https://hackage.haskell.org/package/unicode-transforms for normalization https://github.com/jgm/unicode-collation for collation https://github.com/composewell/unicode-data for character database https://hackage.haskell.org/package/unicode-general-category for character database

Thanks! Here's a puzzle. Profiling shows that about a third of the time in my code is spent in normalize from unicode-transforms. (Normalization is a required step in the algorithm but can be omitted if you know that the input is already in NFD form.) And when I add a benchmark that omits normalization, I see run time cut by a third. But text-icu's run time in my benchmark doesn't seem to be affected much by whether I set the normalization option. I am not sure how to square that with the benchmarks here that seem to show unicode-transforms outperforming text-icu in normalization. text-icu's documentation says that "an incremental check is performed to see whether the input data is in FCD form. If the data is not in FCD form, incremental NFD normalization is performed." I'm not sure exactly what this means, but it may mean that text-icu avoids normalizing the whole string, but just normalizes enough to do the comparison, and sometimes avoids normalization altogether if it can quickly determine that the string is already normalized. I don't see a way to do this currently with unicode-transforms.