What does this syntax mean (...)

Question

I'm putting my hands into reason-react. In the following code :

let component = ReasonReact.statelessComponent("Component3");
let make = (~name, _children) => {
  ...component,
  render: self => <input type_="checkbox" />,
};

I don't understand what (...) means on line 3. When I delete it I get an error message :

 The record field component can't be found.

  If it's defined in another module or file, bring it into scope by:
  - Annotating it with said module name: let baby = {MyModule.age: 3}
  - Or specifying its type: let baby: MyModule.person = {age: 3}

Answer 1

The representation is called Spread Syntax. This was introduced in ES6.

Definition and example from MDN Docs. Link at the bottom.

Spread syntax allows an iterable such as an array expression or string to be expanded in places where zero or more arguments (for function calls) or elements (for array literals) are expected, or an object expression to be expanded in places where zero or more key-value pairs (for object literals) are expected

function sum(x, y, z) {
  return x + y + z;
}

const numbers = [1, 2, 3];

console.log(sum(...numbers));
// expected output: 6

console.log(sum.apply(null, numbers));
// expected output: 6

More details at : Spread Syntax