Robert Bastian

The remaining work is semver breaking, so moving this to 2.0.

For the record we didn't use `_invariant` in #3294

> It's a bit sad that treating letter, colon, letter as having a word break opportunity after the colon is a case of giving computer syntax needs precedence over natural-language...

`ppucd` seems to be exactly the kind of code that *should not* be in ICU4X's data pipeline. It's an assortment of python scripts that are tightly coupled to ICU4C. Other...

Can you confirm whether collation data is CLDR-derived?

I found it after. I do think the changes here are independent of that though, we'll need a compiled data and a data provider path if we want maximum performance.

> The PR seems to be based on the claim that the current code "uses static_to_owned, which might be blocking optimisations". I'm fairly concerned about this statement because static_to_owned is...

- @sffc - dissolving top-level experimental folder is positive and doable. however I find it useful for all crates to be exactly one level down from the top level. We...

`components/experimental` and `components/meta`?

Do we have consensus on * `experimental/components` -> `components/experimental` * `experimental/{harfbuzz,ecma402}` -> `ffi/` * `experimental/{bies,ixdtf,zerotrie}` -> `utils/` * `provider/macros` -> `provider/core/macros`