> Le 16 janv. 2017 à 18:00, Michael Haufe <[email protected]> a écrit :
>
> The question came up recently on CLJS [1] on how to determine if an object is
> safe to call as a Constructor.
The two following procedures will determine whether an object is a constructor
without running it, according to ES6. (Whether it is safe to call it as
constructor... you need first a definition of "safe".)
(1) Using `class/extends`:
```js
function isConstructor1(f) {
if (f === null)
return false
try {
class c extends f { }
return true
}
catch (e) {
return false
}
}
```
(2) Using `Proxy`:
```js
function isConstructor2(f) {
var p = new Proxy(f, { construct() { return {} } })
try {
new p
return true
}
catch (e) {
return false
}
}
```
—Claude
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
