Why constructors are not curried?

[nojb]

@Yu-zh

Both x and y are correct. So it seems to me the syntax is ambiguous whether the construction A (1, "a") is constructing a multi-arg constructor or a constructor of tuple.

Yes, the syntax is the same in both cases.

@Yu-zh

So why not use the curried form uniformly? Then we can use A 1 "a" and B (1, "a") to solve the previous problem.

In perfect hindsight, this would have been a better syntax choice indeed, but alas, now it is too late to change: it would break every single OCaml program in existence.

@Yu-zh

So I was also wondering about the “revised syntax” is really about? Are they going to be merged into future version of OCaml?

The revised syntax was an alterantive syntax for OCaml that began as part of the (now deprecated) Camlp4/Camlp5 projects. While it solved a number of issues with the classical syntax, it never got enough traction to be adopted, and eventually interest on it faded away.

For more on this topic you may enjoy going through the following two issues and the discussions linked therein:

• https://github.com/ocaml/ocaml/pull/9005
• Allow to manipulate the argument of an n-ary constructor as a tuple by alainfrisch · Pull Request #284 · ocaml/ocaml · GitHub

Cheers,
Nicolas