我应该如何修改
WithArea
函数的areaCalculator
参数的通用类型参数U
,使其扩展当前MixinFactory
实例的基类?type Constructor<T> = new (...args: any[]) => T;
interface IArea {
readonly area: number;
}
class MixinFactory<T extends Constructor<Shape>> {
constructor(public Superclass: T) {}
WithArea(areaCalculator: <U extends Shape & IArea>(ctx: U) => number) {
return new MixinFactory<T & Constructor<IArea>>(class extends this.Superclass implements IArea {
get area(): number {
return areaCalculator(this);
}
})
}
}
class Shape {}
class RectRaw extends Shape {
constructor(
public x: number,
public y: number,
public w: number,
public h: number) {
super();
}
}
const Rect = new MixinFactory(RectRaw).WithArea(ctx => {
return ctx.w * ctx.h;
}).Superclass;
const rect = new Rect(10, 10, 20, 20);
console.log(rect.area);