Thank you all for your answers! Your answers were really helpful. Best, -- Sukyoung
On Aug 30, 2014, at 12:34 AM, Allen Wirfs-Brock wrote: > > On Aug 29, 2014, at 4:07 AM, André Bargull wrote: > >> ... >> >>> We checked with the recent ES6 draft but it seems to have the same issue. >> >> In ES6 it's actually possible to reach that step (8.1.1.2.6 GetBindingValue, >> step 5), albeit it's a somewhat tricky and involves doing unusual things >> with proxy objects: >> >> ,,, >> Proxy objects allow you to define your own [[HasProperty]] implementation >> (the "has" method in the example above). In this case [[HasProperty]] will >> return `true` on the first call in order to report a binding is present in >> HasBinding, but then will return `false` when the binding's presence is >> checked the second time in GetBindingValue. >> > > And in ES5, host object have similar capabilities. I believe we put this > checks in specifically to make sure everything was well defined in the > presence of such host objects. > > Allen > _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
