span “Returns the longest prefix of the list whose elements all satisfy the given predicate, and the rest of the list.” the list here is the ls parameter and ls.head is the first item of the list The two lists are then assigned to packed (containing the longest prefix) and next which contains the rest. … Read more
MD5 is a cryptographic hash function. Cryptographic hashes are one way functions. You cannot reverse a cryptographic hash value, but you can brute force messages to find one. Brute forcing means trying all possible input strings and then checking if the hash value is correct. This is possible because cryptographic hashes are also computationally unique. … Read more
It’ll be perfectly safe with a smart constructor and stored dimensions. Of course there are no natural implementations for the operations signum and fromIntegral (or maybe a diagonal matrix would be fine for the latter). module Matrix (Matrix(),matrix,matrixTranspose) where import Data.List (transpose) data Matrix a = Matrix {matrixN :: Int, matrixM :: Int, matrixElems :: … Read more
The question is a bit too broad to answer it here. But Jonas Bonér, the creator of Akka, explores the relationship between Microservices and Reactive Systems in his free ebook “Reactive Microservices Architecture“, why don’t you read that for a start. Akka is a library/tookit, it’s more low-level and doesn’t guide you towards using certain … Read more
I would go by a string.split(” “).lastOption. But keep in mind that other blank chars may be used instead of space solved Scala. How get last word in String [closed]
You can foldLeft over the input string, with a state of List[(Char, Int)]. Note that if you use Map[Char, Int], all occurrences of each character would be added up, weather they’re beside each other or not. s.foldLeft(List.empty[(Char, Int)]) { case (Nil, newChar) => (newChar, 1) :: Nil case (list@(headChar, headCount) :: tail, newChar) => if … Read more
Your use of for does not behave as you expect. You’re using this for-comprehension: for (data <- category(i)) { if (data.startsWith(x)) true else false } This expression “desugars” into (i.e. is shorthand for): category(i).foreach(data => { if (data.startsWith(x)) true else false }) foreach returns Unit, and therefore the type of this expression (and the type … Read more
You can use pattern matching to determine which type of Array you’re dealing with. def arrTest[A](a :Array[A]) :Boolean = a match { case sa :Array[String] => sa.length < 2 || sa.sliding(2).forall(x => x(0) < x(1)) case ia :Array[Int] => ia.length > 2 && ia(0) == 1 && ia(1) == 1 && ia.sliding(3).forall(x => x(0) + … Read more
A regex is not necessary: “/text/text/text/” stripPrefix “https://stackoverflow.com/” stripSuffix “https://stackoverflow.com/” or if you know they’re always there: “/text/text/text/”.tail.init 0 solved Remove symbol “/” at start and end of string
That is a recursive method that just calls itself. It creates an infinite loop. 3 solved What does “def loop: Boolean = loop” do in Scala
You can use standard Java image processing libraries from Scala. It depends on how you want to process your images. Java Image IO Processing Java Image Filters Scala Pure Image library Please reply with in hours my job is at stake If you are telling us that you need to learn Scala, Java, image processing, … Read more
Given List: val myList = List( “IDENTIFIER, a, b, c”, “IDENTIFIER, d, e, f”, “INFORMATION, a, b, c”, “INFORMATION, d, e, f” ) Using, myList.map(_.split(“,”)).groupBy(_.head).mapValues(_.map(_.tail.mkString(” “).trim)) In Scala REPL: scala> myList.map(_.split(“,”)).groupBy(_.head).mapValues(_.map(_.tail.mkString(” “).trim)) res91: scala.collection.immutable.Map[String,List[String]] = Map(IDENTIFIER -> List(a b c, d e f), INFORMATION -> List(a b c, d e f)) scala> 0 solved Scala … Read more
You could achieve this as follows: import java.nio.file.Paths val path = “/home/gmc/exists.csv” val fileName = Paths.get(path).getFileName // Convert the path string to a Path object and get the “base name” from that path. val extension = fileName.toString.split(“\\.”).last // Split the “base name” on a . and take the last element – which is the extension. … Read more
A few pieces of information that might help when looking at code like this: Calling an object or class as a function calls the appropriate apply method if there is one Parentheses are often optional so another way to rewrite the code above would be: val route = HttpService.apply({ case GET -> Root / “hello” … Read more
Here is an informal explaination: The map() method, when applied to a collection of one type of thing (e.g. a collections of lines in a file) and provided a function (e.g. extract the second and third item from the given string) will return a collection of the results of applying that function to each item … Read more