Scala For Comprehensions are Their Own Reward
val one = "This checks for scala or sbt patterns"
val two = "java rocks"
val sentences = List(one, two)
val dict = List("scala", "sbt", "patterns")
val result = for {
sentence <- sentences
does = dict forall sentence.contains
} yield (sentence, does)
//result: List[(String, Boolean)] = List((This checks for scala or sbt patterns,true), (java rocks,false))
Given a list of sentences the comprehension checks to see if every word in a dictionary (list) appears in each sentence and returns a list of pairs containing the sentence and the result.
For comprehensions are really powerful, and useful applications of functional programming concepts such as map
and flatMap
, in a sugared expressive style. One of the many reasons Scala is such an interesting and fun language to use.
This is a good post that describes the idiomatic applications of the for comprehension in Scala.
Written by Ahmad Saad Ragab
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2 Responses
Somehow I have never become interested in Scala, despite it being so functional and having a number of interesting and strong sides, like you've indicated. Regardless, thanks Ahmad for showing this.
Btw. the link to the article at nerd.kelseyinnis.com seems to be broken. Just saying.
Thank you for the comment. If TIOBE Indexes are to be believed you are almost certainly in the majority. Also, thanks for the heads-up about the link, it seems to be a common error on coderwall.