Rewrite the PG uniq function to return the array in a consistent order

[dlglin]

This is to address #1275. Find a MWE to test there.

With this update (supplied by @drgrice1 ) uniq now always returns the array in the same order.

[drgrice1]

Looks good. Of course it is the code I gave you, so this probably doesn't say much!

[pstaabp]

Looks good.

Does this work because grep keeps the same order as the input? Whereas using a hash doesn't preserve order?

[duffee]

Your other option is to use the List::Util's uniq function. The module has been in core since 5.7-5.10 which is old enough to expect it in all(?) distributions. That decision hinges on your feeling about adding dependencies. Like the grep solution above, it also returns results in the same order and may have been optimized for speed. Just a thought.

[drgrice1]

Does this work because grep keeps the same order as the input? Whereas using a hash doesn't preserve order?

Yes. That is basically it.