Comment by refulgentis

Don't wanna name names, because it's on me, it's a miracle it exists, and works.

I don't think there's a significant # of alternatives, so hopefully Flutter syntax highlighting library, as used in a package for making markdown columns, is enough to be helpful.

Problem was some weird combo of lots of regex and an absolutely huge amount of code. It's one of those problems it's hard for me to draw many conclusions from:

- Flutter may be using browser APIs for regex, so there's some sort of JS/WASM barrier copying cost

- The markdown column renderer is doing nothing at all to handle this situation lazily, i.e. if any portion of the column is displayed, syntax highlighting must be done on the complete markdown input

- Each different color text, so pretty much every word, gets its own object in the view hierarchy, tens if not hundreds of thousands this case. Can't remember if this is due to the syntax highlighting library or the markdown package

- Regex is used to parse to code and for all I know one of them has pathological performance like backtracking unintentionally.