New circular Seq operations: rotateRight, rotateLeft, startAt

[mcallisto]

I would like to add to Seq several operations, all related to considering a Seq (or a subtype) a circular sequence.

If you take a look at my library repo at https://github.com/scala-tessella/ring-seq, these are all the methods that I have in mind.

But I started here adding just three, since I need to get used to the intricacies of the Scala collections.

If this is of interest, I will have many more questions on how to correctly add other methods.

[mcallisto]

Any positive or negative comment about this proposal?

[OndrejSpanel]

I am not sure if this method should exists. When I have read its description, I though: but this is the same as rotateLeft. Once I have checked the implementation, I see it really just calls it.

[mcallisto]

@OndrejSpanel I can definitely see your point.

The reason why, at the end, I went for the proposed duplication is that startAt accepts an index, while rotateLeft accepts a number of steps. Even if the result is the same, depending on how you see the circular sequence both can feel more natural.

Just as an example, startAt plays nicely with reflectAt another method you can find in my more complete and documented RingSeq library, see https://scala-tessella.github.io/ring-seq/usage.html