Action proxies

[Brendan Eich]

David Bruant wrote:
>     // notif proxies
>     trap(...args){
>         // pretrap code
>         return () => {
>             // post-trap code
>         }
>     }
>
> In the last snippet, the engine has to store the result of 
> Reflect.trap(...args) internally, but that's not worse than storing it 
> in a variable as it would currently be the case. I think that having 
> this storage internal may even open the door to optimizations that 
> would be harder if not impossible to achieve with current proxies.

Maybe, but this is irrelevant to the allocation of the arrow-function 
closure.

> Thinking about it more, since the posttrap can't modify the return 
> value, it can be seen like a "finally" block. So return-value related 
> allocation characteristics of a notif proxy with a post trap are 
> comparable to the allocation characteristics of:
>
>     function f(){
>         try{
>             return 'https://www.youtube.com/watch?v=08WeoqWilRQ'
>         }
>         finally{
>             console.log('finally')
>         }
>     }

No, that's not a closure. It's not free either, but there's no closure 
allocation.

/be