[Feature] Implement spread operator for objects and arrays allowing the direct insertion of another object or array

[Luna-Klatzer]

Is there an existing proposal for this?

• I have searched the existing issues

This feature does not exist in the latest version

• I am using the latest version

Proposal

Add support for the spread syntax, which allows the direct insertion of arrays or objects into other arrays or objects.

Examples:

• Arrays:

  var arr1: Array<num> = [1, 2, 3];
  var arr2: Array<num> = [4, 5, 6];
  
  var newArray: Array<num> = [...arr1, ...arr2, 7, 8, 9]; // -> [1, 2, 3, 4, 5, 6, 7, 8, 9]

• Objects:

  var obj1 = {
    x: 1,
    y: 2,
  };
  var obj2 = {
    z: 3,
  }
  
  var newObj = {
    ...obj1,
    ...obj2,
  };

Exact behaviour / changes you want

• Add syntax for the spread operator into the parser and allow it as a valid member of array and object literals.
• Add built-in functions spreadArr and spreadObj, which implement the underlying functionality.
• Add appropriate type checks and implement code generation for JavaScript and TypeScript.