On Jun 12, 2012, at 11:44 PM, Thaddee Tyl wrote: > Besides, it often has a similar meaning: I have seen in a lot of code > a de-facto standard wherein null is used to indicate a value that is > voluntarily undefined. You can see this pattern all over node.js code, > for instance.
I *think* this is the key point, but I'm still trying to figure out the implications. I believe you're right, and I think it calls into question the "undefined means no-value, null means no-object" mantra. In practice, I think it's really "undefined means uninitialized, null means no-value." > Harmony's default parameters will make this easier, while letting a > null value through -- which will make this pattern even more common. This confuses me. If default parameters *don't* treat null as requiring a default, won't that work against this pattern? > Besides, the null value can be obtained from the standard library, > when calling certain methods. > Object.getPrototypeOf(...), string.match(...), even calling the toJSON > method of a Date can return null. > Having a way to deal with those return values by providing a default > value would be nice. That's a pretty strong argument IMO. Dave, still mulling _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
