**disclaimer** I know this has been brought up before, but bump :> People are experimenting with polyfilled class implementations, which don’t all correctly throw when called as a function (no `new`). Eventually, they’re likely to be disappointed that this isn’t legal, and might have to undergo some serious pains to fix their applications.
I notice that this is particularly problematic for AngularJS, because classes are registered with an injector, which doesn’t know if it can `[[Call]]` them or not. It will later on try to `[[Call]]` (depending on how the class was registered with DI). It would be really great if we had a way to determine if this was going to throw or not, other than looking at the stringified value of a function, so that these libraries could be updated to accomodate new class behaviour without pains (try/catch or processing Function.toString()) Some ideas: Reflect.isConstructor(fn) -> true if Class constructor, generator, or legacy (and non-builtin) function syntactic form Reflect.isCallable(fn) -> true for pretty much any function, except for class constructors and a few builtins I know it’s way too late for ES6, but maybe some kind of fast-tracked extension is in order? it should be pretty simple to implement these (and SM and v8 have variations of these in the runtime anyways) _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss