[goldenkey]

Attribute selectors have the worst performance of any selector. Coupling that with the =~ operator is even more cause for concern. This is why classes and id exist.

[batbomb]

I'm not sure, but from the post it's actually ~=.

The =~ variant is used in Perl and Bash as a regex matching operator.

[ratbeard]

No, :nth-last-child(n) has the worst performance of any selector.

[bGriz]

span:nth-last-of-type(2n+1):not(div) > span ?

Edit: I reversed my edits to maintain proper history.

[ratbeard]

Actually, I spoke to soon. Since selector engines work right to left, this would first narrow down the list of elements to all the spans in the document. Assuming thats a fairly small percentage of the overall tags in the document, this selector runs at .0023 ms on my MBP w/ 8 GB or RAM.

Sa'll good.

Edit: For the record, bGriz edited his comment, making my comment invalid.

Edit (2): Thanks!

[bGriz]

Definitely fact.

[ratbeard]

Yea, thats slower for sure.