twitter/algebird — pull request #356 by asciola (2014-11-07 22:11:53+00:00)
Title: Add Array Monoid & Group.

Adding monoid & group for arrays.

The monoid takes the provided arrays and does pair-wise addition of the elements. If one array is longer than the other, the result is longer.size in length with the items from the longer copied over. zero returns an empty Array.

The group extends the monoid and implements negation by calling negate on the individual items of the array.