In the preceding examples, we showed how to use monoids in order to achieve certain things. However, if we look at the previous example, we could simplify it in the following way:
object FeatureCountingOneOff { def main(args: Array[String]): Unit = { val features = Array("hello", "features", "for", "ml", "hello", "for", "features") System.out.println(s"The features are: ${ features.foldLeft(Map[String, Int]()) { case (res, feature) => res.updated(feature, res.getOrElse(feature, 0) + 1) } }") }}
In fact, each example could be rewritten to a representation similar to the preceding code.
While someone might be tempted to do things this way, it might not always be scalable. As we already mentioned, the purpose of monoids is ...
