bmaggi

Creating a clean gh-pages branch

This is the sequence of steps to follow to create a root gh-pages branch. It is based on a question at [SO]

cd /path/to/repo-name
git symbolic-ref HEAD refs/heads/gh-pages
rm .git/index
git clean -fdx
echo "My GitHub Page" > index.html

bmaggi

Conform [1] The general classifier must be an element stereotyped by Viewpoint.
Conform [2] The specific classifier must be an element that is stereotyped by View.\

Expose [1] The client must be an element stereotyped by View.\

View [1] A view must only conform to a single viewpoint.
View [2] The derived value of the viewpoint is the classifier stereotyped by Viewpoint that is the general classifier of the generalization relationship stereotyped by Conform for which the View is the specific classifier.
View [3] The derived values of the stakeholder attribute are the names of the classifiers stereotyped by Stakeholder that are the values of the stakeholder attribute of the general classifier of the generalization relationship stereotyped by Conform for which the View is the specific classifier.\

Viewpoint [1] The derived values of the method attribute are the names of the methods of the operations stereotyped by the UML Create stereotype on the classifier stereotyped by Viewpoint.\

bmaggi

import java.util.Arrays;
import java.util.Collection;

import org.eclipse.emf.common.util.Diagnostic;
import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.util.Diagnostician;
import org.junit.Assert;
import org.junit.Test;

bmaggi

/**
 * On an online test the recursive method exited with 
 * java.lang.StackOverflowError
 * 
 * I suppose that the while should have worked better 
 * but my local test only exit with java.lang.OutOfMemoryError: GC overhead limit exceeded for both implem
 * 
 * TODO: limit jvm parameters to get the StackOverflowError
 *
 */

bmaggi

// floating addition/multiplication are commutative but not associative with big numbers
val small = 1e-200
val big = 1e200
val invBig =  -big

(big +invBig)+small //  Double = 1.0E-200
big+(invBig+small) // Double = 0.0

List(big,invBig,small).reduceLeft(_+_) //  Double = 1.0E-200
List(big,invBig,small).reduceRight(_+_) // Double = 0.0

bmaggi

case class A()
case class B()

val b1 = B()
val b2 = B()
val sB = Seq[B](b1,b2)

sB match {
  case _:Seq[A] => println("niet")
  case _:Seq[B] => println("da")

bmaggi

import org.json4s.FieldSerializer._
import org.json4s.jackson.Serialization
import org.json4s.{DefaultFormats, FieldSerializer}

case class Data(id: Int)

implicit val format = new DefaultFormats {} + FieldSerializer[Data](
  renameTo("id", "@id"),
  renameFrom("@id","id")
)

bmaggi

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.Duration;
import java.util.Date;
import java.util.TimeZone;

class TimeChange {
    public static void main(String[] args) throws ParseException {
        timeForward("Europe/Paris", "2019-03-31 01:59:59", Duration.ofSeconds(2).toMillis()); // FRANCE +1

bmaggi

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.Random;
import java.util.UUID;
import java.util.concurrent.ThreadLocalRandom;
import java.time.Instant;

class JavaRandom {

    public static void main(String[] args) {

bmaggi

import java.util.Optional;

public class FunIsOptional {

    public static void main(String[] args) {
        Integer i = 0;
        System.out.println(Optional.of(i).map(v -> v++).orElse(i--));
        //         => res = 0 (orElse is evaluated even when not empty)
    }