Does anyone have a pointer to the mailing list post/write-up about OCaml catching a Unicode algorithm bug?

I think it was caught in one of @dbuenzli 's projects? Something about the OCaml typechecker pointing out a redundant or perhaps non-exhaustive case?

I’m looking for it as a ‘wow’ proof of OCaml/type safety benefit :slight_smile:


I believe you are referring to this UAX #14 for 13.0.0: LB27 first's line is obsolete from Daniel Bünzli via Unicode on 2020-03-03 (Unicode Mail List Archive) ?



Technically it’s not a bug, it pointed out a rule that was no longer needed in the Unicode line breaking algorithm.

Here’s my message to the unicode mailling list.


Thanks both! Saving for future reference :slight_smile:

Reading that message a year later I deeply regret saying “my compiler” on that list rather than “the OCaml compiler”. It does tell that there are not that much (enough ?) other compilers in my life…

But I insist this is not about a bug. A motto out of this would be “Luc Maranget (et al.) and the OCaml compiler keep your specifications clean”.

The proposed update for Unicode 14.0.0 has the fix.


It’s quite amazing how the rule looks almost exactly like the OCaml pattern. Domain modelling, indeed.