Hi,
I'm talking about
http://wiki.ecmascript.org/doku.php?id=harmony:proto_climbing_refactoring#refactoring_hasproperty
The 2 first steps of the proposed algorithms are:
1. Let prop be the result of calling the [[GetOwnProperty]] internal
method of O with property name P.
2. If prop is not undefined, return true.
If O is a proxy, it means that the getOwnPropertyDescriptor trap is
being called. This sounds a bit silly considering handlers have an
"hasOwn" trap which is what could be expected to be called.
It would turn the [[HasProperty]] algorithm to the more elegant:
1. Let hasOwn be the result of calling the [[HasOwnProperty]] internal
method of O with property name P.
2. If hasOwn is true return true.
3. Let proto be the [[Prototype]] internal property of O.
4. If proto is null, return false
5. Return the result of calling the [[HasProperty]] internal method of
proto with argument P.
In the ES5 world, [[HasOwnProperty]] or "[[GetOwnProperty]]+check if
prop !== undefined" is equivalent, but proxies make visible the
difference and in the context of the "in" operator, "hasOwn" seems like
a more relevant trap to call instead of getOwnPropertydescriptor.
David
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