shelajev

enum Hairstyle {
  LONG,
  SHORT
}
class Person {
  static final double LONG_RATIO = 0.4;
  static final int MAX_AGE = 100;
  static final int MAX_HEIGHT = 200;
  public final Hairstyle hair;
  public final int age;

shelajev

public static Person[] generatePeople(int total) {
  Random r = new Random(10);
  Person[] people = new Person[total];
  for (int i = 0; i < total; i++) {
    people[i] = new Person(
      r.nextDouble()<LONG_RATIO ? Hairstyle.LONG : Hairstyle.SHORT,
      (int)(r.nextDouble() * MAX_HEIGHT),
      (int)(r.nextDouble() * MAX_AGE));
  }
  return people;

shelajev

@Benchmark
public double shortHairYoungsterHeight() {
  double averageAge = Arrays.stream(people)
    .filter(p -> p.hair == Hairstyle.SHORT)
    .mapToInt(p -> p.age)
    .average().getAsDouble();
  return Arrays.stream(people)
    .filter(p -> p.hair == Hairstyle.SHORT)
    .filter(p -> p.age < averageAge)
    .mapToInt(p -> p.height)

shelajev

@Benchmark
public double volleyballStars() {
  return Arrays.stream(people)
    .map(p -> 
      new Person(p.hair, p.age + 1, p.height))
    .filter(p -> p.height > 198)
    .filter(p -> p.age >= 18 && p.age <= 21)
    .mapToInt(p -> p.age)
    .average().getAsDouble();
}

shelajev

const http = require("http");
const span = require("ansispan");
require("colors");

http.createServer(function (request, response) {
    response.writeHead(200, {"Content-Type": "text/html"});
    response.end(span("Hello Graal.js!".green));
}).listen(8000, function() { console.log("Graal.js server running at http://127.0.0.1:8000/".red); });

shelajev

git clone https://github.com/graalvm/graalvm-demos
cd graalvm-demos/scala-days-2018/scalac-native/scala-substitutions
sbt package
cd ../

$GRAALVM_HOME/bin/native-image -cp $SCALA_HOME/lib/scala-compiler.jar:$SCALA_HOME/lib/scala-library.jar:$SCALA_HOME/lib/scala-reflect.jar:$PWD/scalac-substitutions/target/scala-2.12/scalac-substitutions_2.12-0.1.0-SNAPSHOT.jar \
  -H:SubstitutionResources=substitutions.json,substitutions-2.12.json \
  -H:ReflectionConfigurationFiles=scalac-substitutions/reflection-config.json \
  -H:Class=scala.tools.nsc.Main \
  -H:Name=scalac

shelajev

from random import random
from math import log
rate = 3
result = []
for i in range(1000):
    result += [-1/rate * log(random())]

shelajev

import polyglot
# Create an R function and save it to python variable
rcode = "function(x, l) ks.test(as.vector(x), 'pexp', l)$p.value"
kstest = polyglot.eval(string=rcode, language="R")
# invoke the R function with arguments that are Python objects
pvalue = kstest(result, rate)
print("The p-value of the test is ", pvalue)

shelajev

# load the R package lattice and open a window for plotting
polyglot.eval(string="library(lattice); awt()", language="R")
# Create R function that draws a histogram
plot = polyglot.eval(string="function(y) {print(histogram(~as.vector(y), main='Hello from Python to R', xlab='Python List')) }", language="R")
# invoke the R function from Python
plot(result)

shelajev

svg()
print(histogram(...))
svgCode <- svg.string()

png('/path/to/image.png')
print(histogram(...))
dev.off()