- Passing option values to optional parameters
let multiply = (~x=1, ~y=1, ()) => x * y;
multiply(~x = ?Some(14), ~y = ?None, ()); // 14
~foo = ?foo
~foo? // equivalent to the ~foo =? foo
let square = (~x=?, ()) => multiply(~x?, ~y=?x, ());
- Single-argument match functions
let divTuple =
fun
| (_, 0) => (-1)
| (x, y) => x / y;
- Operators
(+)(7, 1);
let (+++) = (s, t) => s ++ " " ++ t;
[image:DA85BCBE-66AD-4142-83DF-72AAA68F867E-513-0000F115F3CB4651/B32D2315-3D65-4DB4-ADDD-A6F12389EDE1.png]
let (@-) = (x, y) => x - y;
// According to the operator table, if it starts with an @ symbol,
// it is automatically right-associative
3 @- 2 @- 1 // 2
- Polymorphic functions
polymorphism: making the same operation work for several types
// let id: ('a) => 'a = <fun>;
let id = x => x;
// ListLabels.map: (~f: ('a) => 'b, list('a)) => list('b)
