array/masks

[shannonmoeller]

Gets multiple values from items in an array.

var customers = [ ... ];
var names = customers.map(picks('firstName', 'lastName'));

[shannonmoeller]

Justification:

http://stackoverflow.com/questions/17121316/how-to-pluck-multiple-attributes-from-a-backbone-collection

[nickstark]

Just an idea, I like the name mask for this, but it also makes a difference how it would work functionally if a value doesn't exist.

Intuitively, I think they do slightly different things.

var customers = [
    { name: 'jeff', parkingSpace: 22 },
    { name: 'mike' }
];
var pickedSpaces = customers.map(picks('parkingSpace')); // [{parkingSpace:22},{parkingSpace:undefined}]
var maskedSpaces = customers.map(masks('parkingSpace')); // [{parkingSpace:22},{}]

Thoughts?

[shannonmoeller]

The only difference between those two results would be the resulting value of key in obj and obj.hasOwnProperty(key). I think we should pass through values, if any, unmodified, so that the resulting object looks as similar to the original as possible:

{ name: 'jeff', parkingSpace: 22 } // -> { parkingSpace: 22 }
{ name: 'jeff', parkingSpace: undefined } // -> { parkingSpace: undefined }
{ name: 'jeff' } // -> { }

[nickstark]

I think that's the better behavior, too. So going along with that, I like the name masks better. I would confuse picks with plucks all the time. Then we'd have a slice/splice situation.

[shannonmoeller]

Works for me. I was just aping mout (http://moutjs.com/docs/v0.9/object.html#pick).