#10 Subarrays

[Dennis]

It would be useful to have an operator returning all (non-empty?) subarrays (as in subsets) of a given array.

Example:

[1 2 1]eS "returns [[1] [2] [1 2] [1 1] [1 2 1]] ";

[Martin Büttner]

Alternatively, getting all (non-unique) subsequences might be good too. The result for input [1 2 1] would be

[[1] [2] [1] [1 2] [1 1] [2 1] [1 2 1]]

I also considered all substrings, but I suppose that can be achieved reasonable well with few, like

_,f{)ew~}

Not particularly golfy, but certainly doable. In fact, getting all subarrays as in subsets can be done from there with :$_&, so getting an operator for subsequences might actually be more useful. I'm not sure how I'd implement that conveniently at the moment.