Comment by uryga

they allow as many operations as you need, just pass in a "method name" :)

  const p = Point(3, 5)
  p('getX') // 3
  p('up', 11)('toString') // "Point(3, 16)"


  const Point = (x, y) => (method, ...args) => {
    switch (method) {
      case 'getX': return x;
      case 'getY': return y;
      case 'toString': return `Point(${x}, ${y})`
      case 'up': return Point(x, y+args[0]);
      // ...
    }
  }

(unfortunately statically typing this statically requires... some work, either sth like [typescript overloads + literal types] or full on dependent types)