My interpretation of these spec sections: (new bound) instanceof bound => (new Bar()) instanceof bound // bind's Construct defers to the targetFunction and ignores bound thisValue => bound.[[HasInstance]](new Bar()) // meaning of instanceof => Bar.[[HasInstance]](new Bar()) // bind's HasInstance defers to the targetFunction => true // normal HasInstance
Similarly for 'new bound instanceof Bar'. IE and Firefox both appear to agree with this result. Luke -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of John-David Dalton Sent: Tuesday, August 16, 2011 7:27 AM To: [email protected] Subject: Function#bind [[HasInstance]] question. Sorry about the last empty reply, GMail got ahead of itself :D So Chrome and Firefox disagree on their Function#bind implementation. http://es5.github.com/#x15.3.4.5.2 http://es5.github.com/#x15.3.4.5.3 ~~~ js function Bar() { return 1; } var bound = Bar.bind({}); new bound instanceof bound; // Firefox reports `true`, Chrome `false` (I think Chrome is right) new bound instance of Bar; // Firefox and Chrome report `true` ~~~ The test262 doesn't appear to cover this case. What is the correct result of `new bound instance of bound;` and why? -JDD _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
