Improve clean debug build speeds 25% by changing unicode-linebreak to xi-unicode

[kettle11]

Hi! I'm quite excited for this library.

I'm a big fan of super lean build times so I try to audit dependencies to find areas to improve. In this case it seems unicode-linebreak implements a rather chunky build.rs script that makes it your second slowest building dependency (after swash).

xi-unicode pre-bakes the unicode tables without a build.rs so it builds much faster.

Swapping is an easy one-line change:

Change this line:

cosmic-text/src/font/matches.rs

Line 246 in ac83f58

for (end_lb, _) in unicode_linebreak::linebreaks(span) {

to this:

for (end_lb, _) in xi_unicode::LineBreakIterator::new(span) {

Alongside the obvious cargo.toml changes.

Edit: I ran editor-test and it reported "All lines matched!". I haven't ran further tests.

[jackpot51]

Thanks, I will look into this, would you want to make a PR?

[kettle11]

Yup! Here's a PR: https://github.com/pop-os/cosmic-text/pull/6/commits

[jackpot51]

Merged!