Milan Straka and I agree that we want Data.Sequence to offer pattern synonyms to make it more convenient to work with the ends of sequences. I wanted to check with everyone here what names to use. Relevant names already exposed:

1. <|, |>, and empty for cons, snoc, and empty
2. data ViewL a = EmptyL | a :< Seq a, and the equivalent on the right.

I suggested Empty, :<<, and :>> as the pattern synonyms, the latter chosen for the relative convenience of the double tap. Milan suggested (correctly, I suspect) that the greater clarity of Empty, :<|, and :|> is worth the price in typing.