If we ever have the idea to introduce throw-when-trap-is-undefined handlers

David Bruant bruant.d at gmail.com
Fri Oct 19 07:46:56 PDT 2012


This is just a short note.
In the previous design, some internal proxy operations threw when there was
a missing fundamental trap. We also considered at some point making missing
traps of Handler (previously VirtualHandler) [1] throw as well (I suggested
to make Object.getPrototypeOf(VirtualHandler.prototype) === Reflect, it's
still in the open issues).

I was playing with ES6 maps and I implemented a proxy wrapper for maps to
make them looks like objects (syntactic sugar) [2]. I wanted all irrelevant
traps to throw. It took about 5-6 lines to define a meta-handler as you'll
see, so maybe it's not worth defining "throw-if-undefined trap" when
another useful (and more complicated to implement) solution can be found.


[1] http://wiki.ecmascript.org/doku.php?id=harmony:virtual_object_api
[2] https://gist.github.com/3918227
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