fancellu’s gists

fancellu / combine.scala

Last active August 29, 2015 14:17

Combines 2 maps of sequences. Have seen this asked a few times. This is a fairly concise solution.

	def combine[K,V](map1:Map[K,Seq[V]], map2:Map[K,Seq[V]]) =
	(map1.toList ++ map2.toList).groupBy(_._1).mapValues(_.map(_._2).flatten).map(identity)

fancellu / CaseTuple.scala

Created March 19, 2015 23:14

Case to tuple and back

	case class Person(name:String,age:Int)

	val dino=Person("dino",48) //> dino : stuff.Person = Person(dino,48)

	// get tuple from case class, decompose
	val (name,age)=Person.unapply(dino).get //> name : String = dino
	//\| age : Int = 48

	// create case class from composed tuple
	val dino2=Person.tupled((name,age)) //> dino2 : stuff.Person = Person(dino,48)

fancellu / FirstToFinishMost.scala

Last active August 29, 2015 14:17

Quick coding test. Given tasks to people, find person with most tasks, that finished first

	// Broken apart to ease understanding.
	val s1=Seq(1,1,1,2,2,2,3,3,3,3,4,4,4,4,1)

	val groups=s1.groupBy { identity }

	val sizes=groups.mapValues { _.size}
	val maxSize=sizes.values.max
	val maxUsers=sizes.filter(_._2==maxSize).keys.toSet
	val pop=s1.filter(maxUsers).zipWithIndex
	val lastPlaces=pop.groupBy(_._1).mapValues(_.last)

fancellu / DropNth.scala

Created July 30, 2015 18:46

Drop Nth element from List alternative soltuion

	http://aperiodic.net/phil/scala/s-99/p16.scala

	Mine

	def dropNth[A](n: Int, ls: List[A])=
	ls.grouped(n).flatMap(_.take(n-1)).toList

	---------

	val li=List('a, 'b, 'c, 'd, 'e, 'f, 'g, 'h, 'i, 'j, 'k)

fancellu / RotateN.scala

Last active August 29, 2015 14:26

RotateN to left : Alternate solution for http://aperiodic.net/phil/scala/s-99/p19.scala

	Alternate solution for

	http://aperiodic.net/phil/scala/s-99/p19.scala

	def rotate[A](n: Int, ls: List[A])=
	if (ls.isEmpty) ls
	else{
	val (first,last)=ls.splitAt((if (n>=0) n else ls.length+n)%ls.length)
	last:::first
	}

fancellu / InsertAt.scala

Created July 31, 2015 11:49

InsertAt.scala Alternative for http://aperiodic.net/phil/scala/s-99/p21.scala

	Alternative for http://aperiodic.net/phil/scala/s-99/p21.scala

	def insertAt[A](e: A, n: Int, ls: List[A]) =
	ls.patch(n, List(e), 0)

	insertAt('new,1,li) //> res1: List[Symbol] = List('a, 'new, 'b, 'c, 'd)
	insertAt('new,0,li) //> res2: List[Symbol] = List('new, 'a, 'b, 'c, 'd)
	insertAt('new,99,li) //> res3: List[Symbol] = List('a, 'b, 'c, 'd, 'new)

fancellu / SparkShellDebugOff.scala

Created August 6, 2015 11:20

Spark shell too chatty, want to turn off logging and can't be bothered to edit log4j files?

	// Just run this inside the spark shell, no more chatty logs

	import org.apache.log4j.Logger
	import org.apache.log4j.Level

	Logger.getLogger("org").setLevel(Level.OFF)
	Logger.getLogger("akka").setLevel(Level.OFF)

fancellu / Insert.scala

Created August 30, 2015 15:03

Simple insertion into an ordered List

+val li=List(1,2,10,20,30)                         //> li  : List[Int] = List(1, 2, 10, 20, 30)
+def insert[T](li:List[T],x:T)(implicit cmp:Ordering[T])={
+ val (first,last)=li.partition {cmp.lteq(_, x) }
+ first:::x::last
+}                                                 //> insert: [T](li: List[T], x: T)(implicit cmp: Ordering[T])List[T]
+insert(li,11)                                     //> res0: List[Int] = List(1, 2, 10, 11, 20, 30)
+insert(li,10)                                     //> res1: List[Int] = List(1, 2, 10, 10, 20, 30)
+insert(li,9)                                      //> res2: List[Int] = List(1, 2, 9, 10, 20, 30)

fancellu / T1.scala

Last active September 10, 2015 15:27

ScalaJS ractive example - Live demo http://dinofancellu.com/demo/scalajsRactive/

	package example
	import org.scalajs.dom
	import scalajs.js.annotation.JSExport
	import scala.scalajs.concurrent.JSExecutionContext.Implicits.runNow
	import dom.ext.Ajax
	import scalajs.js
	import js.Dynamic.literal
	import com.felstar.scalajs.ractive._

	@JSExport

fancellu / Checkout.scala

Last active October 9, 2015 11:19

Checkout Kata CodeTest in Scala

Dino Fancellu fancellu