Action proxies

David Bruant bruant.d at
Mon Feb 4 14:05:07 PST 2013

Le 04/02/2013 22:41, David Bruant a écrit :
> Le 04/02/2013 19:57, Tom Van Cutsem a écrit :
>> The post-trap could be cached and reused, but only if the 
>> post-processing is independent of the specific arguments passed to 
>> the intercepted operation.
> Is there any harm in passing the trap arguments to the post-trap 
> function additionally to the result?
I've played with post-traps a bit. A place I would naturally store the 
post-trap to cache it is the handler.

Assuming trap arguments are passed to the post-trap, another idea is to 
have pre and post traps. It duplicates the number of elements in a 
handler, but not the size of the code (or marginally assuming pre/post 
traps are longer than the boilerplate). Having a post-trap would still 
be an opt-in, but the protocol to get it would be "callable 
handler.[[Get]]" instead of the current "callable pretrap-return". One 
allocation per handler would become the natural default (while the 
current natural default is a function literal as return value).


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