Play Framework and Functional Programming

Check this post if you are interested in the Play Framework and how functional programming is used in a web framework. This is an example of composable data manipulation:

	val linkedInProfiles: List[Profile] = …
	// 1: Keep only profiles of young people
	val youngProfiles: List[Profile] = linkedInProfiles.filter (p => p.age < 25)
	// 2: Group these profiles by skill
	val skillToProfile: List[(Skill, Profile)] = for {
	p <- youngProfiles
	s <- p.skills
	} yield (s, p)
	val profilesBySkill: Map[Skill, Profile] =
	skillToProfile
	.groupBy{ case (skill, profile) => skill) }
	.mapValues{ case (skill, profiles) => profiles }
	// 3: For each skill determine the number of profiles
	val skillsWithPopularity: List[(Skill,Int)] =
	profilesBySkill.mapValues( profiles => profiles.count )
	// 4: Order results by number of profiles and take top 10 skills
	val top10Skills: List[(Skill, Int)] =
	skillsWithPopularity
	.sortBy{ case (skill, count) => - count}
	.take(10)

view raw DataManipulation.scala hosted with ❤ by GitHub

If you are confused by the Iteratees mentioned in previous post, take a look at this post.