The cost of nested methods
- by Palimondo
In Scala one might define methods inside other methods. This limits their scope of use to inside of definition block. I use them to improve readability of code that uses several higher-order functions. In contrast to anonymous function literals, this allows me to give them meaningful names before passing them on.
For example:
class AggregatedPerson extends HashSet[PersonRecord] {
def mostFrequentName: String = {
type NameCount = (String, Int)
def moreFirst(a: NameCount, b: NameCount) = a._2 > b._2
def countOccurrences(nameGroup: (String, List[PersonRecord])) =
(nameGroup._1, nameGroup._2.size)
iterator.toList.groupBy(_.fullName).
map(countOccurrences).iterator.toList.
sortWith(moreFirst).head._1
}
}
Is there any runtime cost because of the nested method definition I should be aware of?
Does the answer differ for closures?
