delete operator

[dijs]

Cannot use "delete" to remove object properties...

[rzimmerman]

I'm a little torn on this one...

JavaScript's delete is quirky and sometimes confusing. For example:

x = function () {return 2};
delete x();

Doesn't throw any errors or indicate any issues (except in strict mode, which Kal doesn't use at this time).

var y = 2;
delete y;

Just does nothing.

Is there something better we can do?

[dijs]

The only reason you should use delete if for object properties, not variables or functions.

For the problem I had, I solved it without using the delete operator by assigning it a value of 'undefined'

[cmwelsh]

There is no equivalent to the delete keyword. The best option is to warn people in the documentation to be careful.

http://perfectionkills.com/understanding-delete/

[rzimmerman]

A couple options would be:

1. Do nothing and just note in the readme that delete isn't supported
2. Just support JavaScript-style delete (really easy)
3. Support delete, but do compile-time checks to make sure they aren't trying to delete variables and are only deleting a property or array index.
4. Make something "new" that is more useful and less confusing.

I'm ok with number 1 if nobody can think of a use case that really benefits from delete.

I don't like number 2 because I think it's confusing to anyone who isn't already a JavaScript expert.

Number three isn't bad, but I worry people will try things like:

x = [1,2,3]
delete x[1]
print x.length

and expect to get 2.

However, I don't think

x = {a:1,b:2}
delete x.a
print x.a

Is confusing.

For number 4, the best idea I have is:

delete property a from x
delete item 3 from y
delete items 10 to 20 from z

In this case I'd use splice rather than delete for the arrays. I think this would prevent people from even trying things like delete a.

But I'm looking for thoughts.

[dijs]

4 is sick! That would be awesome syntax to have.

[cmwelsh]

Sounds like 4 would encourage the correct usage.