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