Nullable values sort order

[Munter]

The current documentation doesn't mention how nulls are sorted on each of the sort functions.

Would it be possible to add a sort option that allows configuration on if nulls should be sorted first or last?

[cosimochellini]

Hey, @Munter you're right, I've never had this need, but it's a legit feature.

What about if we add a defaultNullValue in the sortable options, so you can choose the value to use instead of the null value?

[johnw42]

I don't think defaultNullValue is the right approach, because it's easily simulated using byValue, and it doesn't support what I consider the two most reasonable behaviors:

• Sort null after all other values
• Sort null before all other values

There are similar issues involving undefined and NaN, and especially handling combinations of null, undefined, and NaN in the same array. I'm not entirely convinced the exact ordering matters so long as it's documented, and more importantly, consistent. NaN is especially hairy because dealing with it naively leads to an inconsistent comparison function, which in turn can cause Array.prototype.sort to produce unpredictable results.

I'll put out a proposal I'm not crazy about becuase of its complexity, but which I think covers all the possible user requirements. Add two new array-valued options, "sortFirst" and "sortLast". The arrays can contain only null, undefined, and NaN, and putting the same value in both arrays is an error. I think maybe an example is the best way to describe the semantics. Consider this set of options:

{ sortFirst: [null, NaN], sortLast: [undefined] }

In this example, sorting with the comparator will put all nulls at the start of the array, followed by all NaNs. Next will be all the ordinary values (i.e. not null, undefined or NaN), and finally all undefined values will be but at the end of the array. Any value not appearing in either array will be sorted to a default position we can figure out later.

[cosimochellini]

I've thought about it a little bit, and a possible solution could be to add an option,

byNumber({ valuesOrder : // the name is temporary :)
  [
   'null',
   'undefined',
   'NaN',
   'others' // all the number not null | undefined | NaN (also this name is temporary)
  ]
})

So the developer is able to choose the correct order of all the possible values that arrive in the array.
Passing directly the values is more tricky since NaN is a "little bastard" in terms of reference.

Any thoughts?

PS:
A quite big downside about adding this feature is that the performance of the sorting procedure is going to be way slower

[johnw42]

Yeah, I like strings better.

…

On Tue, Aug 8, 2023 at 3:52 AM Cosimo Chellini ***@***.***> wrote: I've thought about it a little bit, and a possible solution could be to add an option, byNumber({ valuesOrder : // the name is temporary :) [ 'null', 'undefined', 'NaN', 'others' // all the number not null | undefined | NaN (also this name is temporary) ]}) So the developer is able to choose the correct order of all the possible values that arrive in the array. Passing directly the values is more tricky since NaN is a "little bastard" in terms of reference. Any thoughts? — Reply to this email directly, view it on GitHub <#11 (comment)> or unsubscribe <https://github.com/notifications/unsubscribe-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ou are receiving this email because you commented on the thread. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub> .