> It is pretty common to want to map over an Enumerable, but only include the elements that match a particular filter. A common idiom is: > > enum.map { |i| i + 1 if i.even? }.compact > > It is of course also possible to do this with two calls: > > enum.select { |i| i.even? }.map { |i| i + 1 } > > Both cases are clumsy and require two iterations through the loop. I'd like to propose a combined method: +1 for a combined map and select. I find myself reaching for it every so often and wishing it were there.