Hi Bob, you can find more details about the syntax change and discussion in
this slightly outdated PR: https://github.com/facebook/reason/pull/1299

Long story short, you can write let add((m, n)) = m + n.

Note that the ReasonML project actually includes several long-time members
of the OCaml community. I feel that the new syntax has very well received
in the JavaScript community and it will lead to wider OCaml adoption. It's
a win-win situation.

Regards,

Yawar

On Sun, Dec 10, 2017 at 1:12 PM, Robert Muller <robert.muller2@gmail.com>
wrote:

> The team developing ReasonML seems to be experimenting with concrete
> syntax in an effort to make it feel as familiar and natural as possible to
> JavaScript programmers. Seems like a good idea. But the present version
> seems to hardwire parentheses awkwardly for function definitions and calls.
> Parentheses are required for both function definitions and calls. So one
> writes
>
> let incr(n) = n + 1       and   incr(5)
>
> but not
>
> let incr n = n + 1        or    incr 5
>
> Fair enough, but for multi-argument functions the parser seems to unroll
> the parenthesized items (both parameters & arguments) to leave curried
> functions. E.g.,
>
> let add(m, n) = m + n  or equivalently let add = (m, n) => m + n
>
> then add(5, 3) is 8 as one would expect. But the (m, n) in let add(m, n) =
> ... isn't a pattern matching a pair, it's the JS-style sequence of input
> parameters and the definition unrolls to let add = (m) => (n) => ... . So
> add(5) : int -> int and all three of add(5, 3), add(5)(3) and { let add5 =
> add(5);  add5(3) } are 8. There's probably a way to write an add function
> of type int * int -> int, but I don't know how to write it.
>
> I'm wondering what the OCaml community makes of this. I find it awkward.
> Bob Muller
>
>
>