The needle/haystack thing is the crucial part as you say in the blog. Since grapheme, word separation and sentence segmentation rely on rules that are updated o

The needle/haystack thing is the crucial part as you say in the blog. Since grapheme, word separation and sentence segmentation rely on rules that are updated on each unicode version it indeed would be out of place in the standard library. Ideally I'd want them (libicu) on the system level, e.g. standardised in POSIX in libc so that language developers shouldn't need to worry about them.