I find the idea interesting and some of the arguments convincing, but I’m a bit worried that a forum place could end up feeling like a wasteland of (often half-baked) ideas because of the lack of people available to evaluate them, provide feedback and turn them into effective implementations. There is a general asymmetry/imbalance where it is much easier and less effort-demanding to say than to do, to propose than to implement, and encouraging the former without an effective strategy for the later may be ineffective, and even possibly a source of frustration.
In communities with an established RFC process like C#, Rust or Haskell, one of the very real criticisms is that “RFCs end up being ignored” – and those communities have many more people working full-time on the language evolution than OCaml. @whitequark, who did some excellent work on handling RFCs in the Rust community, may have feedback on that.
The worry is not merely hypothetical, we already have the issue at the level of github Pull Requests (PRs), with many more people willing to send new PRs than to review existing PRs. And PRs already have the property that, because they require implementation work, they tend to be modest in scope and effect. The difference in cost versus work demanded for open-ended proposals can be much wider. For example, everyone has idea on how wonderful flambda could be if only it optimized X better, and almost no one is available to invest work in actually improving flambda.
We could consider having such a Proposal forum as a time-limited experiment, just like we did for Github Pull Requests initially: have it for six months, see whether it has a clear positive impact, otherwise close it and invite people to keep using Mantis / PRs.
@mjambon: I’m not sure “GADTs vs. namespaces” is a fair comparison given that it is actually easier to propose a convincing GADT design than a convincing namespace design (there was one attempt at doing GADTs and it succeeded, so far there have been at least two attempts to design namespace systems (one by myself, one by Pierrick Couderc) that did not work out).