Scala Treeset example: partition

var ts_keys = new TreeSet[KbdKey]()(new CompareRowThenCol())

val (ts_inferiorOrEqualRowKeys,ts_superiorRowKeys) = ts_Keys.partition(_.i_row<=i_row)

class CompareRowThenCol extends Ordering[KbdKey] {
    def compare(k1: KbdKey, k2: KbdKey) = k1.value-k2.value
}